PHD16 User’s Manual

READ THIS MANUAL BEFORE ATTEMPTING TO CLEAN YOUR PRINT HEADS

● Practice cleaning on a bad print head.

● Test the print head on a printer to make sure it’s recovered, before you
start working on another one.
● Do not clean more than 1 print head at a time, especially when you’re new
to the process.
● Do not attempt any reverse flushing if the print head is still in a good
shape. You may clog it if you don’t take the required precautions.
● Test the pressure control on your PHD machine before connecting a print
head to it.
Print Head Doctor 16
User’s Manual

WARNING: Wear chemical goggles! The recovery fluids are extremely

irritating to the eyes and eye protection is mandatory.

WARNING: Earth your PHD machine. Use the AC plugs with the ground
pin and the grounded wall outlets. Do not use 2-wire extension cords.

WARNING: Print heads can be damaged by excessive use of

ultrasound, pressure, temperature and aggressive chemicals. It is
always a good idea to minimize the risk of a print head damage by
using no ultrasound, low pressures, low temperatures and less
aggressive recovery fluids (1X, R-UV, 4UV, 1DX, 1W). If no progress can
be made this way, you can start introducing short periods of
ultrasound, warming up the fluids, and using more aggressive
chemicals.

Most print heads are sensitive to ultrasound. A low-frequency

(28-40kHz) ultrasound is more destructive to the print heads, and
should be avoided. Our 75kHz ultrasonic tanks are a safer solution.
Always start with a low-power mode by pressing the “P” button on
the tank, then setting the numbers to 25 using the arrow keys beside
it, and then pressing “P” again.

What to Expect of the Print Head Doctor

Owning a production printer is similar to owning a car. If you do a periodic service, it will last a long time. Stop
doing oil changes and a scheduled maintenance to your car, and you’ll ruin the engine. The same happens to
the print heads. If you never take care of them, they will get clogged, and it will be extremely difficult to recover
them. But if you don’t let your heads clog by flushing them on a regular basis, they will never get clogged and
can serve you for many years to come.

Print Head Doctor is by far the best solution on the market for unclogging and maintaining all kinds of inkjet
print heads. However, it cannot do miracles. Don’t expect it to unblock a print head completely clogged with a
cured UV ink. Nothing can save it. Clean your print heads before they get fully blocked. As soon as you see
deflected or fuzzy nozzles, it’s time to flush that print head. It will take less effort from you and it will be safer for
the print head itself.

Because there are so many printing inks out there, there is no universal cleaning fluid that can unclog any print
head. We had to work hard to come up with a range of recovery chemicals. While we have pretty universal
solutions that work with a variety of inks and print heads, it still remains to be determined which one will work
best for your print head and ink. We recommend starting with a print head that has no value to you. Remember
that while you’re learning how to use the machine, you may damage the print head.

Print Head Sensitivity

Here is the list of print heads sorted by sensitivity in an ascending order. Less sensitive print heads can handle
more pressure, temperature, ultrasound and chemistry. Less sensitive heads can be cleaned starting with Step
3 below. Others should go through steps 1 and 2. If you are working with Epson heads, please read our
manual on Epson head recovery with PHD, as they are way too sensitive and require extra care.

Spectra S-class: SL128, SM128, SE128 Very low sensitivity Spectra Q-Class, Polaris Medium to high sensitivity

Spectra Nova and Galaxy Low sensitivity Ricoh Gen4, Gen4L, Gen5 High sensitivity

Konica-Minolta KM512 Medium sensitivity Xaar 500 Medium to high sensitivity

Konica-Minolta KM256 Medium sensitivity Xaar 1001/1002/1003 Medium to high sensitivity

Konica-Minolta KM1024 Medium sensitivity Kyocera KJ Medium to high sensitivity

Xaar 128 Medium sensitivity HP Aprion High sensitivity

Seiko SPT510 and SPT508 Medium sensitivity Epson DX4, DX5, DX6, DX7 Very high sensitivity

HP X2* Medium sensitivity Epson Micro Piezo TFP High sensitivity

Hitachi (Ricoh) Gen3 Medium sensitivity Epson - all models Very high sensitivity

Kyocera KJ4 Medium sensitivity HP Thermal Printheads Very high sensitivity

*HP X2 print heads can be cleaned with the original HP MF10 and MF26 cleaning fluid. It is approved for use
on the Print Head Doctor machines without affecting the warranty.
Explanation of the Recovery Cycles
Dr - Drain Cycle - is used to empty the tank, or when you need to pump fluids in a forward direction for a short
time. Connect the drain tube to any of the ports on the upper row of the panel.
C - Combined Forward - pumps the fluid into the print head and sucks it out of the RF cap. Also known as
Vacuum-Assisted Forward Flushing. Your print head(s) must be in the RF slot of the adapter. To identify the RF
slots, look at the slots in the adapter down into the tank. The non-RF slots are open, and you should be able to
see the tank bottom through them. The RF slots aren’t open. They have a slot with 2 tubes connected to it.
F - Forward - only the pressure pumps will work (no vacuum). Do not use this cycle if your RF tubes are
connected to the machine. Use Forward12 instead.
R - Combined Reverse - Vacuum-assisted reverse flushing: the pressure is fed to the RF cap and the vacuum
is connected to the print head ports.
S - Reverse - Reverse flushing without vacuum. The pressure is applied to the RF cap. This is a legacy cycle
which is not recommended to use on a PHD16.
M - Mesh - Mesh cleaning cycle. To be used on print heads with two input ports. Pressure is applied to one
port and vacuum is applied to the other. The fluid will clean the internal mesh of a print head without pushing
on the nozzles.
P - RF Cap Flush - Flushing cycle for the RF Caps equipped with two ports. The pressure is applied to one
port of the RF cap and vacuum is applied to the other one.
V - Vacuum - Reverse flushing using only a vacuum. Pressure pumps won’t be used. The print head must be
connected to the vacuum ports of the machine. Make sure the print head’s nozzle plate is clean and the fluid in
the ultrasonic tank is clean. This cycle should not be used when the RF tubes are connected. Use Vacuum12
instead.
U - Ultrasound - Ultrasonic treatment without pumping fluid. This one is usually used as part of custom cycles.
L - Alternating - It alternates between Forward and Vacuum.
O - Foward12 - This is the main cleaning cycle, which applies pressure to all ports in the upper row. The RF
tubes can be connected to the bottom row, as the pressure won’t be applied to them.
B - Forward34 - This cycle pressurizes the ports of the bottom row on the Pro panel (3 and 4). The upper row
ports are closed off.
E - Vacuum12 - It applies vacuum to the top row of the Pro panel, while the bottom row ports are closed.

Useful Tips

Protect your print head’s electronics from the fluids. Wrap the areas where fluids may get on the electronics
with tape. Make sure that the print head is submerged into the fluid by only 3mm (1/8”) and not deeper.

Do not clean your print head for too long. One hour a day will be enough. Before installing the print head on
your printer, test the nozzles by pushing the flushing solution that came with your ink through the print head
using a syringe. Do not apply too much pressure. Once you see the nozzles are in a good condition, put the
head on the printer. Otherwise you’ll need to re-flush it.

Do not use alcohol to clean the electronics of a print head. If you want to remove moisture from the electronic
parts, use the spray-on Contact Cleaner that can be found in automotive parts stores.
Note on UV Print Heads

UV curable ink, when fully cured, creates a very chemically resistant polymer. If your UV print head is clogged
with a cured UV ink, the chances for recovering that head are close to zero. It’s much easier to clean the
heads that are not completely blocked. Flush your print heads with a PHD machine on a regular basis, or as
soon as you see the signs of head clogging: a few missing, deflected or overspraying nozzles. Better yet, flush
your print heads regularly even if they seem to be OK. Prevention is the best medicine.

Do not set your expectations too high for UV print heads. A completely blocked print head is considered DOA
(dead on arrival). There are very slim chances of unclogging such heads.

Precautions on Epson Heads

Epson heads are extremely sensitive to everything. Follow these precautions to keep them safe during
recovery, and disregard the pressure settings shown on the diagrams in this document. Epson heads cannot
handle any kind of pressure applied to the input ports. Keep the print head pressure at a maximum of 2 psi.

Do not use a 40kHz ultrasound, as it will damage Epson heads. A 75 kHz ultrasound is much safer. We are
offering 75 kHz ultrasonic tank upgrades for all models of Print Head Doctor. Even with a 75kHz ultrasound,
you should set the power output of the tank to a minimum (25%) by pressing the P button on it, then setting 25
with the arrow buttons, then pressing P again. At 25%, the sonic power is only 12W, which is safer for print
heads.

Do not preheat the recovery fluid over 30°C, or let it run at room temperature. Watch the temperature: it should
not get warmer than 30°C.

The most effective way of cleaning Epson heads with non-automatic PHD machines (models below 15) is by
using a vacuum-assisted forward flushing method with the maximum forward pressure of 2 psi. There is no
limit to the vacuum: it can be as high as it gets. Vacuum cannot damage print heads.

A PHD16 can clean Epson heads better than any other, because it can automatically switch between pushing
and pulling the fluid, which requires a lot of operator work when using older models.

Do not clean your print head for too long. One hour a day will be enough. Purge the print head with a weak
flush and then with air, gently pushed by a syringe, and let it sit for a day without any fluids inside.

Notice on HP X2 Print Heads

We recommend using the fluid called H-UV which is designed for work with HP inks, which is compatible with
the original MF10 solution to clean HP X2 print heads
Machine Controls

This is the controls layout for PHD16.

Button # 1 serves as a Start and Pause button for the cycles. When the display prompt says PRESS START,
this button will start the cycle. When the cycle is running this button will pause it. It will resume the cycle if it’s
been paused.

Button # 2 is a software-assigned button. The lower line on the LCD will show the function of this button.

Button # 3 is the info button. It will show the serial number of the PHD machine and the Bluetooth PIN
(password) that you will need for connecting with Android devices. This button gives you access to the
PARAMS (parameters) menu, where you can adjust the default pressure, vacuum, cycle time and drain time.

Button # 4 is a software-assigned button. The lower line on the LCD will show the function of this button.

Select / Pressure Adjust knob is used to navigate through menu items on the display, or to adjust the set
pressure.

Button # 5 switches between an automatic and manual pressure control. It’s not recommended to switch to
a manual pressure control.

Auto / Manual LED indicates the current mode of control: Red for Manual, Green for Automatic.
Relief Valve knob is used to relieve the pressure quickly. Keep it closed at all times.

Intake Vacuum Gauge shows the vacuum past the input filters. Its purpose is to detect if the input filters are
clogged and need replacing. When the vacuum is deeper than 15” Hg, it means the filters must be replaced.

Automatic Pressure Control

The automatic pressure control on PHD16 will maintain the desired pressure in the output pressure ports of the
machine. Keep the Relief Valve (RV) closed at all times and the machine will control pressure
automatically.

Now the machine will maintain the current pressure. The display will show the actual pressure / set pressure.
For example, 6.2 / 7.0p means that the target pressure is 7 psi and the current pressure is 6.2 psi.

You can adjust the set (target) pressure with the knob near the LCD.

Any time during the cycles or in a standby mode you can switch between the automatic and manual modes. Be
careful with a manual mode, because it’s very easy to over-pressurize the print head this way.

Ultrasonic Tank Controls

As long as the ultrasonic tank is connected to the AC power, it will work automatically. However, the built-in
heater must be controlled on the tank itself. Use the arrow buttons to set the desired temperature. The two
numbers on the tank’s panel show the actual fluid temperature and the set temperature.

Do not use the fluid heater if there isn’t enough fluid in the tank. It must be filled up to the waterline (the
step in the wall). Always press the Reset button when you’re about to empty the tank. This will turn off the
heater.

If you are using more than 20% ultrasound on the cycles, you will increase the fluid temperature above the
set point due to the work of the ultrasound.

A 75kHz ultrasonic tank has a control for the output power. You can set between 25% and 100% of the full
power (50W). It’s highly recommended to set the sonic power to 25% to minimize the risk of print head
damage. Press the “P” button, then set the numbers to 25 using the arrow keys, then press “P” again. This
should be repeated every time the tank’s power is reset.

Ultrasonic Treatment

How the ultrasound works: the bottom of the tank vibrates at a high frequency (75 kHz), creating sonic
waves in the liquid. These waves create microscopic bubbles that will subsequently burst. When they burst
near the contaminant which clogged a print head, they cause it to break loose from the wall of a print head.
Therefore the ultrasonic treatment is highly effective for print head cleaning. Such treatment is more
productive when the fluid isn’t moving, therefore the PHD machines will pause pumping when turning the
ultrasound on, and resume pumping while it’s still on.

The side effect of using the ultrasound on print heads is that it may cause print head destruction or electronic
failure. Sensitive print heads (such as Epson) will get damaged after just 1 minute of ultrasonic treatment. More
robust print heads can handle a decent amount of ultrasound without adverse effects. We recommend using it
in moderation. Start with only 5% of ultrasound per cycle. If that doesn’t help fully clean a print head, increase it
to 10% or 20%.

Another side effect of the ultrasound is fluid heating. Almost all of the sonic energy converts to heat, causing
the fluid in the tank to heat up. Such heating is a bad thing when it exceeds safe limits (40..45°C). We
recommended stopping the machine and allowing it to cool down. At the same time, a moderate heat of 30°C
will help the chemicals work better.

Pro Panel

The upper row of the Pro Panel has 8 quick-connect fittings for the print heads. A print head must be
connected to ports 1 and 2.

The bottom row contains fittings for RF connection. The clear tubes from the adapter (normally 2 tubes per 1
RF slot) must be connected to ports 3 and 4.

The port assignment on the Pro Panels is as follows.

Pro Panels shipped before January 2021 Pro Panels shipped after January 2021

The PHD16 Pro Panel has a pneumatic input at the back. It needs a compressed air at the pressure between
80 and 100 psi.

Pro Adapters

PHD16 is designed to work with Pro Adapters, which:

- Permanently stay on the ultrasonic tank and normally don’t need to be removed.
- Use the compressed air to secure the print heads in place.
- Do not need any screws to install or remove a print head.

KM1024 Hexa Pro Adapter

It allows cleaning up to six KM1024 / KM512i print heads at once if not using an RF slot, or up to 2 print heads
in an RF slot.
Print head Name Allowed Cycles Max Pressure Max Vacuum
slot

1, 8 RF slot Mesh 8 psi - Reverse 8” Hg - Mesh

Forward Combined Combined
Reverse Combined 13” Hg - All other
RF Cap Clean 4 psi - All other cycles cycles
Ultrasound

2,3,4,5,6,7 Open slot Mesh 5 psi - Mesh 8” Hg - Mesh

Forward12
Vacuum12 6 psi - Forward12 15” Hg - Vacuum12
Ultrasound

A Pro adapter has 4 clear tubes attached to it. These are called “RF Tubing” and they must be connected to
the ports on the lower row of fittings on the Pro panel as shown on the picture below. The black air tube
connects to a black fitting on the right side of the 2nd row of a Pro panel.

Tip: moisten the quick-connect fittings on the ends of the clear tubing before connecting them to the Pro panel.

KM1024 Print Head Installation on a Pro Adapter

To install a print head on a Pro adapter:

● Place it into a desired slot. If you are just starting with head recovery, use the open slots (2-7).
● Make sure the print head is vertical and not tilted.
● Holding a print head with one hand, flip the air switch on the Pro panel. The air cylinders will extend and
secure the print head in place.
● Connect tubes with quick-connect fittings to both sides of a print head.
● Attach the quick-connect fittings to the ports 1 and 2 on the upper row of the Pro panel. You can pick
any ports 1 and 2.
Kyocera Dual Pro Adapter
It allows cleaning up to two Kyocera KJ4 print heads at the same time on the open slots (2, 3), or 1 print head
in an RF slot (1).

Print head Name Allowed Cycles Max Pressure Max Vacuum

slot

1 RF slot Mesh 8 psi - Reverse 8” Hg - Mesh

Forward Combined Combined
Reverse Combined 13” Hg - All other
RF Cap Clean 4 psi - All other cycles cycles
Ultrasound

2,3 Open slot Mesh 7 psi - Mesh 8” Hg - Mesh

Forward12 9 psi - Forward12
Vacuum12 15 psi - Forwar12 for 15” Hg - Vacuum12
Ultrasound 5 seconds only

A Pro adapter has 2 clear tubes attached to it. These are called “RF Tubing” and they must be connected to
the ports 3 and 4 on the lower row of fittings on the Pro panel. Use any two adjacent ports on the bottom row.
The black air tube connects to a black fitting on the right side of the 2nd row of a Pro panel.
Kyocera print head installation on a Pro adapter

To install a Kyocera print head on a Dual Pro adapter:

● Place it into a desired slot. If you are just starting with head recovery, use the open slots (2,3), which
will capture the print head magnetically. When installing in the RF slot (1), hold the print head with one
hand, flip the air switch on the Pro panel. The air cylinders will extend and secure the print head in
place.
● Connect tubes with quick-connect fittings to both sides of a print head.
● Attach the quick-connect fittings to the ports 1 and 2 on the upper row of the Pro panel. You can pick
any ports 1 and 2.
● If you want to clean two print heads at the same time, connect each one of them to ports 1 and 2 (left
side of a print head to port 1, right side to port 2).

Seiko IRH2513 Quad Pro Adapter

It allows cleaning up to four Seiko IRH2513 print heads at once.
Print Name Allowed Allowed Max Pressure Max Pressure Max Vacuum
head Cycles with Cycles with Damper without
slot Damper without Damper
Damper

2, 4, 6, RF slot Forward Mesh, 8 psi - 8 psi - 8” Hg - Mesh

8 Combined, Forward Reverse Reverse
Reverse Combined, Combined Combined 13” Hg - All
Combined, Reverse other cycles
RF Cap Clean Combined, 2.5 psi - All 3.5 psi - All
Ultrasound RF Cap other cycles other cycles
Clean,
Ultrasound

1,3,5,7 Open slot Forward12, Mesh, 3 psi 3 psi - Mesh 8” Hg - Mesh

Vacuum12, Forward12,
Ultrasound Vacuum12, 6 psi - 15” Hg -
Ultrasound Forward12 Vacuum12

A Pro adapter has 8 clear tubes attached to it. These are called “RF Tubing” and they must be connected to
the ports on the lower row of fittings on the Pro panel (ports 3 and 4). The black air tube connects to a black
fitting on the right side of the 2nd row of a Pro panel.

Seiko IRH2513 print head installation on a Pro adapter

Seiko print heads have a built-in damper. It cannot handle pressure higher than 2.0 psi. You can clean a print
head with a damper on it, or you can remove the damper and connect the tubes directly to the two ports on the
print head - this method should be used if you couldn’t recover a head with the damper on, because it allows a
more aggressive cleaning.

To install an assembled Seiko print head on a Pro adapter (without removing a damper):

● Place it into an RF slot (2, 4, 6, 8), hold the print head with one hand, flip the air switch on the Pro
panel. The air cylinders will extend and secure the print head in place.
● Connect a tube with a metal nut to the input fitting on a print head. Make sure there is an o-ring under
the nut, otherwise it won’t seal.
● Attach the quick-connect fittings to the ports on the upper row of the Pro panel. If you are connecting
several print heads, make sure they are connected to ports 1 and 2 (not just to 1 or just to 2).

To install a Seiko print head without a damper on a Pro adapter:

● Remove the damper from your print head.

● Connect 2 tubes to the print head: one to the main (central) port, another one to the side port. Make
sure the tubes are sitting tightly. You may need to wipe the inlet ports on a print head dry before
connecting the tubes.
● You can place a print head onto an RF slot (2, 4, 6, 8) or an open slot (1, 3, 5, 7), hold the print head
with one hand, flip the air switch on the Pro panel. The air cylinders will extend and secure the print
head in place.
● Connect the 2 tubes from a print head to ports 1 and 2.

Pro Adapters installation instructions

If your Pro adapter came disassembled, read this document.

Print Head Connections on a PHD16

Without a Reverse Flushing (RF) slot:

1. Connect your print head to ports 1 and 2 of the PHD16 machine.

When a print head is sitting in an open slot, you cannot run the Forward Combined or Reverse Combined
cycles or any programs containing these cycles, because they are designed for RFs only.

With a Reverse Flushing (RF) Cap:

● Connect your print head to ports 1 and 2
● Connect the 2 tubes of the RF cap to ports 3 and 4

NOTE: You can run only the following cycles when a print head is in an RF slot:

● Forward Combined
● Reverse Combined
● Mesh
● RF Cap Flush

Adding Fluid to the Tank. Draining the Tank.

If the adapter on the PHD16 is covering almost an entire tank, it’s not easy to pour in the fluid straight from a
bottle.
1. Connect 2 tubes to ports 1 and 2 on the Pro panel.
2. Place the ends of the tubes into the bottle with fluid.
3. Start the INTAKE cycle.
4. Watch the fluid level in the tank. When the fluid covers the o-rings on the bottom of the adapter, stop
the cycle.

To drain the tank, repeat steps 1,2 and run the DRAIN cycle.
Important notes:

The fluid level in the tank must cover the top of the rubber o-rings in the
Pro adapter. If the fluid level drops during cleaning cycles, add some
more fluid.

Do not heat an empty tank! You need to have fluid at a proper level
before you can turn on the heating.

Turn the heating off before draining the tank. Just press the Reset
button.

Do not open the relief valve during the cycles. Keep it fully closed. You
can open it only if you need to drop the pressure to zero quickly.
Print Head Recovery Steps with PHD16

Step 0. Print Head Soaking.

Before you start cleaning a print head on a machine, it’s recommended to soak it. You can soak the nozzle
plate of the print head by placing it onto a lint-free cloth soaked with a recovery solution that is native to your
ink. You can also soak the insides of the print head by pushing a small amount of a recovery fluid into the print
head with a syringe. Leave the print head to sit for some time: from several minutes to several hours,
depending on how badly it’s clogged. Note that some recovery fluids are quite aggressive and therefore you
should limit the soaking time with them down to 15-30 minutes.

● For UV curable inks, a good soaking solution is N-UV, which can be left inside a head for a long time,
then our next strong one is R-UV, then the stronger ones are 7UV and 9UV. Fluid 4UV is not too
effective for soaking, but it’s very good for flushing with a PHD machine.
● For solvent inks, good soaking fluids are X-A, X-B and 4X.
● For water-based inks, use fluids 0W, 1W, 2W, 3W or 4W for soaking, with fluid 4W being the most
effective in many cases, but at the same time 4W presents the highest risk to a print head. Fluid 0W is
very safe and it works best for soaking if you add 20% (by volume) of a 99% IPA alcohol. It’s good for
storing print heads.
● You can use your own cleaning fluids.

Step 1. Through-Head Flushing / Mesh Cleaning

This step will work only with the print heads with two input ports and it will clean the inside channels and the
mesh of the print head without pressurizing the nozzles. It will remove any contaminants that may end up
re-clogging the nozzles if you don’t do this step.

● Mount the print head on the adapter in an open slot.

● Install the adapter with the head on the ultrasonic tank.
● Connect your print heads to ports 1 and 2 on the Pro panel.
● Fill the bath with the recovery fluid. It doesn’t need to touch the print head.
● Set the temperature on the ultrasonic bath to 30° - 35°C.
● Run the cycle called M (Mesh). Keep the pressure at 4 psi and the vacuum at 8” Hg max.
● Depending on the print head condition, the Mesh cycle should run for 3 - 10 minutes.

Step 2. Light Flushing

We will attempt to unclog your print head the safest way possible.
● Use fluid # 1X for solvent print heads, or 4UV for UV curable, or 1W for water-based ones. You can also
use your own fluid recommended by your ink supplier.
● Set the temperature to 30°-35°C. Set up your print head in an open slot.
● Select the Forward12 cycle. Select 0% ultrasound and press START. Using the knob near the LCD,
adjust pressure to a recommended pressure for your type of printhead.
● Check the nozzles. If you see an obvious progress, continue with the forward flushing for another full
Forward12 cycle. If no progress has been observed, move on to the next step. Note: different print
heads require different pressure in order to see the jet curtain: from 5 psi to 14 psi (Kyocera). Usually
the test pressure exceeds the recommended working pressure, therefore you should test the nozzles
very quickly, within a few seconds, and then reduce the pressure.
Step 3. Medium Strength Flushing of Sensitive Print Heads
Continue with the less aggressive recovery fluid.
● Start Forward12 and select 10% ultrasound.
● Check the nozzles after 15-20 minutes.
● If no progress has been made, you’ll need to change the recovery fluid.
● Re-check the nozzles and if there was no progress, move on to Step 4.

Step 4. Powerful Flushing of Robust Print Heads

Please note that this process poses a higher risk for sensitive print heads.

● Run Forward12 with 20% ultrasound for a full length of it.

● Re-check the nozzles.
● If you see a great deal of improvement, repeat the same cycle.
● If no further progress is observed, change the recovery fluid to the next one.
● Repeat the F1 cycle with the new fluid.

Robust print heads can handle as much as 4 hours of continuous flushing, while other heads should be flushed
for no longer than 1...2 hours per day. If no improvement is taking place after each cycle, it means that the
recovery fluid should be changed to another one.

When you’re done cleaning a print head, flush it out with the intermediate fluid, or with fluid 1X (for solvent
heads) or with fluid 0W or distilled water for water-based heads, and fill it with the flushing solution that comes
with your ink.

Vacuum-Assisted Forward Flushing

In this cycle the vacuum is applied to an RF cap attached to the nozzles of your print head, which sucks the
fluid out of it, while pressurized fluid is supplied to the input ports of the print head. Pressure and vacuum work
together to increase effectiveness of the cleaning. Please note: the safe pressure for any Epson head is 2
psi.

Set up your print head in an RF slot.

Run the C - Combined Forward cycle. Make sure the print head pressure does not exceed 4 psi. Very sensitive
print heads will get damaged at 7psi, so you should keep it at no more than 2 psi. For Epson heads, keep the
pressure at 1 - 1.5 psi.

Medium and Low sensitivity print heads can be cleaned with cycle Combined Forward with 20% ultrasound.

Reverse Flushing with an RF Cap

If you have a Reverse Flushing cap for your print head, here is another method of cleaning heavily clogged
print heads. It will run the fluid in a reverse direction, pushing the clog out of the print head as opposed to
pushing it through the nozzles, as it happens during the forward flushing.

Keep the vent hole capped with the screw.

First, we need to clean the insides of the RF Cap. This is very important to prevent clogging of the nozzles
from outside of the print head.
● For sensitive heads: run the Vacuum-Assisted Forward Flushing on C0 cycle for 15 minutes.
● For less sensitive heads: Install the RF Cap on a print head and connect it to the dummy port on the
adapter plate. Connect the print head input to one of the pressure ports of the machine, and plug the
other port. Run the F1 cycle for 15 minutes at a pressure not exceeding 5psi. Make sure the fluid is
escaping from the dummy port on the adapter into the tank.
● If you have a Sonic Flow RF Cap (the one with 2 ports): Connect one port of the RF Cap to the
pressure port of the machine. Connect the second port of the RF Cap to the dummy fitting on the
adapter plate. Run the F1 cycle for 15 minutes with at a pressure not exceeding 5 psi. If you’re working
with a sensitive print head, use F0 instead (Forward without any ultrasound).

Connect the RF Cap to the pressure port and the print head to the vacuum port, as shown on the diagram
above. Run the C1 cycle (for Epson heads use only C0 with no ultrasound). Because all the pressure is
applied to the outside of the nozzles, it’s safe to use a high pressure of up to 10 psi (PHD11,12) or 15 psi
(PHD13,14, 15).

Medium and Low sensitivity print heads can be cleaned with cycle C2, which gives more ultrasound.

After the reverse flushing, you should do a forward flushing and check the nozzles condition.

Changing Over the Fluid

Some recovery fluids are not compatible with each other. They may create a gel-like substance when mixed,
therefore we recommend using the Intermediate / Storage Fluid for a change-over. Alternatively, you can use
fluid N-UV (for UV heads) or the flushing solution that comes with your ink, but you need to test if it’s not
reacting with the other recovery fluids you are using.

Draining the Tank:

● Disconnect the print head(s).

● Connect 1 or 2 drain tubes to ports 1 and 2.
● Place the ends of the tubes connected to ports 1 and 2 into the bottle where the recovery fluid came.
● Make sure the relief valve is fully closed at all times.
● Start the Drain cycle.
● Allow all fluid to be pumped back into the bottle.
● Allow the pumps to run for a few minutes after all fluid is removed from the tank. This will fill the
machine with air.
● Disconnect the drain tubes.
● Re-connect the print heads to the Pro panel.
● Run the Vacuum cycle with 0% ultrasound for 10-20 seconds. This will empty the print heads.

Flushing the Machine with the Intermediate Fluid:

● Now place the ends of the two drain tubes into the tank.
● Add a small amount of the Intermediate Fluid into the tank.
● Run the Drain cycle for just a minute, and let it cycle the intermediate fluid through the machine.
● Stop the cycle.
● Place the output tubes into a waste bottle.
● Run the Drain cycle again, to empty the tank.

Adding a New Recovery Fluid:

● Add the new recovery fluid to the tank.

● Keep the print heads connected to ports 1 and 2.
● Run the Mesh cycle for 5 minutes at 4 psi and 8” vacuum.

Fluid Foaming Issue

Some fluids are loaded with surfactants, which make them very foamy. For example, fluids 1W-4W tend to
foam a lot. The reason for foaming is the air getting into the lines.

Checking for air leaks inside the machine. Make sure the tank is filled by at least 30% with fluid. Put the
tubes from the pressure ports to the tank. Start the F - Forward cycle. Allow it to run for a minute. See if the
fluid coming out of the tubes is clear, without any foam in it. If it’s clear, the machine is fine. If it’s full of foam,
then you’ll need to remove the top cover of the machine and check where the foam is being created in the
lines. Usually this happens at the connections. To fix the leak, tighten the connection (if possible) or replace the
fitting.

Checking whether the foaming is caused by the vacuum pump. Run only the F - Forward cycle. If this
cycle doesn’t create foam, then we’ll need to diagnose the vacuum part.
● Close both vacuum ports with the plugs. Run the V - Vacuum cycle and check for foaming. If it creates
a lot of foam, then it’s the problem with the vacuum pump. Replace the tubing with fittings. If that
doesn’t help, replace the vacuum pump.
● Connect one tube to one vacuum port and plug the second vacuum port. Submerge the end of the tube
into the fluid. Start the Vacuum cycle. If you see a lot of foaming, it’s a leak in the lines, fittings or
connections to the vacuum pump, or in the pump itself. Replace all parts.
If you are doing the Combined flushing cycle and it creates a lot of foam, check if the fluid level reaches
the top of the RF cap. The RF cap must be completely submerged in the liquid, or else it will pick up some air
and create a big amount of foam.

Using Recovery Fluid 4UV

The recovery fluid 4UV is totally different from the rest of the UV fluids (R-UV, 7UV, 9UV, N-UV, J-UV, H-UV). It
is not based on organic solvents. Instead, 4UV contains water, and it is loaded with strong surfactants aimed at
detaching the UV ink residue from the inner walls of print heads. This makes it incompatible with many
solvent-based solutions. If you switch to or from 4UV, you will need to flush the PHD machine and the print
head with our Intermediate / Storage Fluid, or with some other flushing solution that will mix well with both
recovery fluids (sometimes a distilled water will do the job). In some cases you don’t need to flush after 4UV if
you run a quick Mesh cycle to introduce the new fluid.

PHD App for Android

Our Android app allows you to create custom cleaning programs: the sequence of standard cycles with custom
parameters.

Download the PHD app from Google Play store by searching for Print Head Doctor.
Press the Info button on the PHD machine to see the serial number and the bluetooth password.
Launch the PHD app. It will scan for PHD devices. Your device should be identified as

P[serial_number]LE

For example, a PHD16 machine with serial number 54214 will be visible as a bluetooth device P16-54214LE.
Pair with it and enter the BT password. The BT password can be revealed by pressing the INFO button.

In the main screen of the app (see below) you can control the machine, see the progress of the recovery cycle
or program, monitor and adjust the pressure and temperature (if your model supports that).

You can also use the controls on the PHD machine. Anything you change there will be synchronized with the
Android app.
Error Codes

Error Displayed What it means Possible Cause Solution

01.Error P.Pump Pressure pumps current is Pressure pumps If pumps are still running,
too low. disconnected from the it’s a PCB problem. If it’s
PCB not running, check the
pump's connection.
Replace the pumps.

02. Error P.Pump O.C Pressure pumps Pressure pumps are Replace all filters, the
overcurrent. stalling due to intake and the big one. If no
clogging or result, replace the pumps.
overpressure.

03. Error V.Pump Vacuum pump current is Vacuum pump If the vacuum pump is still
too low. disconnected from the running, it’s a PCB
PCB problem. If it’s not running,
check the vacuum pump
connection. Replace the
pumps.

04. Error V.Pump O.C Vacuum pump overcurrent. Vacuum pump is Replace the pumps.
stalling due to
clogging or
overpressure.

06. Over Heat Fluid temperature is too Disconnected or faulty Replace the temperature
high. temperature sensor. sensor.

09. Temp Sens Error Temperature reading is Disconnected or faulty Replace the temperature
unstable. temperature sensor. sensor.

12. Temp Sens Error Fluid temperature is too Disconnected or faulty Replace the temperature
low. temperature sensor. sensor.