Hakko Electronics FM-204 User manual

1
1. PACKING LIST AND PART NAMES
HAKKO FM-204 desoldering station ............... 1
MODEL FM-2024 desoldering tool ................. 1
Filter pipe assembly (For replacement) ............. 1
Control card ................................................... 1
Power cord ..................................................... 1
Connecting cable ........................................... 1
Iron holder with tip cleaner .............................. 1
Handle (for gun configuration) .......................... 1
Cleaning drill (for heating element) ................... 1
Nozzle remover................................................ 1
Ceramic paper filter (For replacement/10 pcs.) .... 1
Instruction manual .......................................... 1
Ceramic paper filter
(10 pcs.)
Receptacle
Card slot
Fuse
Filter case cover Power
receptacle
Power
switch
Control card
Joint band
Filter pipe assebmly
Desoldering tool (Nozzle is not included)
Handle
(for gun configuration)
Cleaning drill
(for heating element) Nozzle remover
Iron holder
Tip cleaner
Power cord
Connecting cable
ON
OFF
*HAKKO FM-2027/FM-2026 (not included)
can be connected to HAKKO FM-204.
*When using above FM-2027/FM-2026
soldering iron, please use it with
the dedicated iron holder.
●HAKKO FM-204 desoldering station
●Accessories
Please check to make sure that all items listed below are included in the package.
●Option
HAKKO FM-2027/FM-2026

4
A. Iron holder
●Operation
First, remove any excess solder from the tip by
thrusting the tip into the cleaning wire. (Do not
wipe the tip against the wire. This may cause
molten solder to spatter.)
1. Insert the holder assembly securely into the
Iron holder base.
2. When the wire becomes dirty or loaded with
solder, turn the wire until a clean surface is
presented.
3. When changing the cleaning wire, lift the case
top vertically to prevent solder debris from
falling out.
4. Place the spare tips in the tip tray.
●Use of the sleep function
When using the sleep function, insert one end of
the connecting cable into the jack at the back of
the iron holder and the other end into the jack at
the back of the desoldering station to connect
them.
CAUTION
• Be sure to turn off the power before connecting or
disconnecting the connecting cable.
• Securely insert the relay cord all the way into the jack.
B. MODEL FM-2024
●Connecting and replacing the filter pipe
Pull the back holder until it locks, then
insert the filter pipe assembly with the opening
to the nozzle side. Ensure that the outer
surface of the filter pipe assembly is even with
the handle support. If the filter pipe assembly
is tilted, a leak may occur.
To replace the filter pipe assembly, press back
holder unlock button , pull the back holder
to lock it, change the filter pipe assembly, then
lock the filter pipe assembly. Replace the filter
pipe assembly in the cartridge.
4. INITIAL SETUP
Jack to connecting cable
Connecting cable
CAUTION
The surface of the filter pipe
assembly may be very hot.

5
Not sensitive to vertical orientation
●
Attaching and replacing the nozzle cartridge
Insert the nozzle cartridge fully into the grip
as shown in the illustration. Once the nozzle
cartridge is inserted, it is locked automatically.
CAUTION
The nozzle can be very hot. To attach or remove the
nozzle cartridge, be sure to use the nozzle remover to
preclude the possibility of breaking the grip or cartridge.
To replace the nozzle cartridge, insert the nozzle
remover into the flange of the nozzle cartridge,
press the nozzle unlock button Aand remove
the nozzle cartridge.
CAUTION
The nozzle may be very hot.
The nozzle remover may be left mounted on
the end of the straight grip when not in use to
prevent it from being misplaced.
●Using the desoldering iron in the gun
configuration.
To use the desoldering iron in the gun
configuration, attach the handle to the straight
grip.
●Using the desoldering iron in the pen
configuration.
To remove the handle, slide down the button
located on the rear of the handle to unlock it,
then slide the handle toward the back of the
MODEL FM-2024.
Inserting the tip:
●Holding the front end of the tip, insert it into
the sleeve assembly.
CAUTION
Insert the tip into the sleeve assembly until it clicks into
place. When you hear it clicks, avoid forcing the tip into the
sleeve assembly.
●Insert the tip securely into the connector.
NOTE:
Improper insertion of the tip will cause to appear
on the display.
Push
Nozzle remover
Align the parts and slide the handle
toward the front.
The handle will be locked
automatically.
1
2
Hold this part to insert the tip into the sleeve assembly.
Hold this part to insert the tip into the connector.
CAUTION
When holding the head of the tip, there is a danger of burn.
Be sure to use the heat-resistant pad.

6
C. Desoldering station
CAUTION
• Be sure to unplug the cord by holding the plug.
• Securely insert the connecting cable all the way into the jack.
●The HAKKO FM-204 detects when the iron is
removed from the iron holder and sends this
data to the station via the connecting cable.
That data is then used for various functions.
●Connection
1. Connect the power cord to the inlet on the
rear of the station.
(Connect the plug from the MODEL FM-2024
to the receptacle on the HAKKO FM-204.)
The HAKKO FM-204 can be used without being
connected to a control box.
CAUTION
Connect the plug to the receptacle, aligning the tab on the
plug with the opening on the receptacle.
2. Put MODEL FM-2024 into the iron holder.
3. Connect the hose from the MODEL FM-2024
to the filter case cover on the HAKKO FM-204
Station.
4. Plug the power cord into a grounded wall
socket.
Ensure that the power switch is OFF before
inserting the AC plug.
Turn the power switches ON.
CAUTION
Be sure to ground this product as it is ESD safe by design.
5. Turn ON the power.
CAUTION
The HAKKO FM-204 does not function properly if the
power is turned on with the trigger pressed. Release the
trigger and then turn the power ON.
Jack to connecting cable
Connecting cable
Plug
projection Push the plug in as far as it will go, and
try to remove it without pressing the
release pin. If it stays in the receptacle it is
properly seated.
Receptacle opening
FM-2024
24V-70W
Insert all the way to the base.

7
Controls and displays
Controls
The front panel of the HAKKO FM-204 has four
controls.
.........End of sequence signal (terminates a
phase of a data entry mode). When
pressed for less than one second,
displays settings already stored.
.........Initiates a data entry mode.
.........Increases the displayed value.
...Decreases the displayed value.
The HAKKO FM-2027 and the MODEL FM-2024
can be connected to the HAKKO FM-204
Station.
The lamp on the grip operates as follows.
In use ................ Lights
Sleep mode....... Blinks slowly
Off mode ........... Off
Error .................. Blinks quickly
Operation
1. Turn the power switch ON.
2. By default, when the set temperature is
reached, the buzzer sounds, indicating that
the unit is ready.
The heater lamp on the front panel starts
blinking.
5. OPERATION
Displays
The HAKKO FM-204 has a three-digit display
element.
Depending on the selected mode, it will display:
●Sensor temperature (of the iron tip)
●Data entry:
Selected quantity (See the data entry
procedures.)
●Temperature scale:
ºC or ºF, depending on selection
●Error detection (See ERROR MESSAGES.)
An audible buzzer is provided to alert the
operator:
●When the station has reached the set
temperature, the buzzer will sound once.
(Default setting)
●When the low temperature threshold has been
crossed, the buzzer will sound continuously.
This buzzer will shutoff when the sensed
temperature returns to the acceptable range.
●When a foreign substance, an incompatible
tip, or the soldering end of the tip is inserted
into the HAKKO FM-2027, the display will
blink and the buzzer will sound continuously.
●When the auto-power shutoff function is
activated and power to the heater is shut off,
the buzzer sounds three times.
CAUTION
By default, the temperature is set to 350ºC.
You can confirm the set temperature by pressing the
button. The set temperature will be displayed for two
seconds.
CAUTION
When not in use, set the iron in the iron holder.
button
button
button
button
Receptacle

8
Insert the card.
Press the or button.
Press the or button.
Press the button once.
Press the button once.
Press the button once.
●
Changing the temperature setting
• MODEL FM-2024
Temperature setting range
ºC................350 to 450ºC
ºF ................660 to 840ºF
• HAKKO FM-2027 (Option)
Temperature setting range
ºC................200 to 450ºC
ºF ................400 to 840ºF
Example: Changing the temperature from
350ºC to 400ºC
1. Insert the control card into the station.
●The hundreds digit of the display begins to
flash. This indicates that the unit has entered
the temperature setting mode and data may
be entered.
2. Enter the hundreds digit.
●Press the or button to set the
hundreds digit. When the desired figure is
displayed, press the button. The tens digit
begins to flash.
3. Enter the tens digit.
●Press the or button to set
the tens digit. When the desired figure is
displayed, press the button. The units
digit begins to flash.
4. Enter the units digit.
●Set the desired units digit in the same way
as for the tens digit, and then press the
button. The temperature is recorded to the
internal memory, and heater control begins
after the new set temperature is displayed.
To change the set temperature with
the control card in the station:
NOTE:
If you enter a value outside the temperature setting range
(see the table above), the display returns to the hundreds
digit, and you have to enter a correct value.
CAUTION
If the power is turned off without completing the
temperature setting, the new set temperature will not
be recorded.
1. Press and hold the button for at least one
second. The current temperature setting is
displayed, and then the hundreds digit begins
to flash one second later. This indicates that
the station has entered the temperature
setting mode.
Follow steps 3 to 4 on “Changing the
temperature”.
2. If the button is not pressed and held for at
least one second, the current set temperature
is displayed, and then the tip temperature is
displayed.

9
●Entering the tip offset value
Example:
When the set temperature is 400ºC and
the actual tip temperature is 410ºC: The
difference in temperature is 10ºC, so enter
–10 as the current offset value.
1. Insert the control card into the station.
●
The station enters the temperature setting mode.
2. Press the button.
●The station enters the offset entry mode.
Press the or button to set the
hundreds digit.
The values that can be entered in ºC or ºF are 0
(for positive values) and - (for negative values).
3. Select or and press the
button.
The tens digit begins to flash. Enter the offset
value.
The values that can be entered to the tens
digit are 0 to 5 in ºC (0 to 9 in ºF).
The tens and units digits are set with the
offset value range.
Allowable offset value range
ºC................. –50 to +50ºC
ºF ................. –90 to +90ºF
If you enter a value outside the allowable
offset value range, the display returns to
the hundreds digit, and you have to enter a
correct value.
CAUTION
In the offset entry mode (when the display is flashing), the
tip temperature is controlled by the current offset value.
4. Verify the tip temperature.
Press the button once.
Press the or button.
Press the or button.
Press the button once.
Press the button once.
Press the button once.
NOTE:
The station stores the offset values for each tip type.
For example, connect the HAKKO FM-2027 to the
station and enter the offset value (–10ºC). Next, change
to the MODEL FM-2024 and enter the offset value
–20ºC). When you reconnect the HAKKO FM-2027, the
offset value is set to –10ºC automatically.
The temperature accuracy of iron tips is ±15°C (±27°F) (except for designated tips) when using the default offset
values. If a higher temperature accuracy is required, use the following offset function:

10
To change the offset value with the
control card in the station:
●Removing solder
Clean the nozzle tip.
Be sure the nozzle tip is tinned with clean,
fresh solder.
If the nozzle tip is coated with oxidation
or contamination, its thermal conductivity
deteriorates. In contrast, if the nozzle end is
wetted with a small amount of clean solder,
its thermal conductivity increases.
1. Melt the solder.
Position the nozzle above the lead to be
desoldered as shown in the illustration and
melt the solder.
CAUTION
Never allow the nozzle to touch the board itself.
Confirm that the solder is melted.
CAUTION
To confirm that all solder is melted, observe the inside of
the hole and the backside of the P.W.B. If this is difficult to
do, try slowly moving the lead with the nozzle. If the lead
moves, the solder is melted. Never move the lead by force.
If it doesn’t move easily, the solder isn’t yet fully melted.
2. Extract the solder.
After confirming that the solder is completely
melted, extract the solder by pressing the
button (or squeezing the trigger).
CAUTION
Never leave any solder remaining inside the hole in the
P.W.B.
3. Problems during desoldering.
If solder remains, resolder the component and
repeat the desoldering process.
1. Press and hold the button for at least
one second.
The current offset value is displayed, and then
the hundreds digit begins to flash one second
later. This indicates that the station has
entered the offset entry mode. Follow steps
3 and 4 for setting the offset value of the tip
temperature.
2. If the button is not pressed and held
for at least one second, the current
OFF set value is displayed, and then the
temperature setting is displayed.
Nozzle
P.W.B.
Solder
Lead
Slowly move
the lead with
the nozzle.
Extract the solder by slowly
moving the lead back and forth
with the tip of the nozzle.

11
6. PARAMETER SETTINGS
●
Parameter entry mode
process
Select the parameter entry mode using the
following operation.
Be sure to insert the control card before opening.
●: Temperature display (ºC
or ºF)
The HAKKO FM-204 has the following parameters.
Number LED display Setting Default setting
Temperature
display or : ºF display
: ºC display ºF display
Auto sleep
time setting Tens digit entry Sleep time 6 min.
Low temperature
error setting Hundreds digit entry
Low temperature
threshold entry
270ºF
Offset-free mode or :Off
: On Off ( )
Buzzer setting
(C-E sound, S-E
sound)
or :Off
: On On ( )
Buzzer setting
(Set temperature
alert)
or :Off
: On On ( )
Auto sleep
on/off setting or :Off
: On On ( )
Auto shutoff
on/off setting or :Off
: On Off ( )
NOTE:
• Each time the or button is pressed, the
display toggles between the following displays:
and .
• When is selected, the parameter number
selection screen in step 2 is displayed.
CAUTION
Do not leave the HAKKO FM-204 for a long time with the
auto shutoff function activated. Turn the power off when
you do not use the HAKKO FM-204 for a long time.
●When the display changes to and
, the station enters the mode for
changing the temperature display.
●Press the or button to switch the
display alternately between (Fahrenheit)
and (Celsius).
1Turn the power on while pressing the
button.
The station enters the parameter entry
mode.
2Select the parameter number.
is initially displayed, and the tens digit
begins to flash. Use the and buttons
to change the parameter setting, or press the
button to select the units digit.
Press the button to go to the next step.
3Select the number for setting the
parameter setting set in the preceding
step.
The current setting is initially displayed.
Use the , , or button to
enter the parameter setting.
Press the button to return to step 2.
4The display changes to , and
the station asks whether to exit the
parameter entry mode.
Select and press the button to
exit the parameter entry mode.
After the necessary parameters are set, press
and hold the button in steps 2or 3above
for two seconds.

12
●: Auto sleep time setting
Set the time until the auto sleep function
activates after the soldering iron is set on the
iron holder.
Auto sleep examples:
Sleep (immediately after the iron is set
on the iron holder)
Sleep (10 minutes after the iron is set on
the iron holder)
NOTE:
• The auto sleep time can be set in units of minutes (up
to 29 minutes).
●
The tip temperature is reduced to approximately
200ºC (400ºF) during sleep mode. The tip
temperature varies significantly, depending
on the ambient environment, tip type and iron
types. 200ºC (400ºF) should only be used as a
guide.
●
When the display is , press the or
button, or remove the soldering iron from
the iron holder to resume power to the heater.
●: Lower temperature
error setting
Lower temperature error
●
When the temperature drops below a set limit,
an error is displayed and the buzzer sounds.
●When the temperature returns within the
allowable range, the buzzer stops.
Low temperature setting range
for Celsius: 30 to 150ºC
for Fahrenheit: 50 to 300ºF
Example:
When the set temperature is 350ºC and the low
temperature error setting is 100ºC, a warning buzzer
sounds when the temperature drops to 250ºC.
Turn the power on while pressing
the button.
Press the or button.
Press the or button.
Press the button once.
Press the button once.
●The hundreds digit begins to flash when
entering the low temperature setting.
Use the method for setting the temperature to
enter and set the low temperature setting.
●If you enter a value outside the low
temperature setting range (see the table on
the left), the display returns to the hundreds
digit, and you have to enter a correct value.
●After the low temperature setting is set, the
display returns to the parameter number
selection screen.
CAUTION
• When the setting temperature is 300ºC (570ºF) or less,
the sleep function cannot be set to Sleep even if the
sleep function is set to ON.
• The tip temperature rises to the setting temperature once
at power on even if the sleep time is set to “0”. The tip
temperature will be reduced to the sleep temperature
after the temperature reaches the set temperature.

13
●: S-E, C-E buzzer sound
setting mode
●In the buzzer sound setting mode, which sets
whether to sound the buzzer when a sensor
error or soldering iron error occurs, either
or is displayed.
: The buzzer does not sound.
: The buzzer sounds.
Select or and press the button.
●: Set temperature alert
setting mode
●In the set temperature alert setting mode,
either or is displayed.
: The buzzer does not sound when
the soldering iron reaches the set
temperature.
: The buzzer sounds when the
soldering iron reaches the set
temperature.
Select or and press the button.
●In the auto sleep setting mode, either
or is displayed.
: The auto sleep function is off,
regardless of the auto sleep set time.
: The auto sleep function is on, and the
auto sleep time is activated.
Select or and press the button.
●: Auto sleep function
setting mode
NOTE:
When the auto sleep function is on, removing the iron
from the iron holder or pressing the or
button resumes operations.
●In the auto shutoff setting mode, either
or is displayed.
: The auto shutoff function is turned off.
: The auto shutoff function is turned on.
Select or and press the button.
●: Auto shutoff function
setting mode
When the soldering iron is set on the iron
holder and is not operated for 30 minutes,
power to the heater is shut off automatically,
and the unit shuts off.
When the auto shutoff function is on, removing
the iron from the iron holder or pressing the
or button resumes operation.
When auto shut-off is activated, the buzzer
sounds, and it sounds again in 30 minutes.
●When the station is in the offset-free mode,
either or is displayed.
: The offset value cannot be entered without
the control card inserted into the station.
: The offset value can be entered without
the control card inserted into the station.
Select or and press the
button.
● : Offset-free mode

14
7. MAINTENANCE
Properly maintained, the MODEL FM-2024 desoldering tool should provide years of good service.
Efficient desoldering depends upon the temperature, and the quality and quantity of the solder and flux.
Perform the following service procedures as dictated by the conditions of the gun’s usage.
WARNING
Since the desoldering tool can reach a very high temperature, please work carefully. Except
when cleaning the nozzle and heating element, ALWAYS turn the power switch OFF and
disconnect the power plug before performing any maintenance procedure.
Cleaning with the nozzle cleaning pin
Cleaning with the cleaning drill
●Before cleaning
●After cleaning
The cleaning pin passes completely
through the hole.
Insert the bit while turning it clockwise.
Pull the drill bit out straight without turning it.
Solder plating
Hole is damaged by erosion.
Maintenance of nozzle
CAUTION
The desoldering tool may be extremely hot. During
maintenance, please work carefully.
Inspect and clean the nozzle
●Plug in the power cord, turn the power switch
ON and let the nozzle heat up.
CAUTION
The cleaning pin will not pass through the nozzle until the
solder inside the nozzle is completely melted.
●Clean out the hole of the nozzle with the
nozzle cleaning pin (not included as a
standard accessories).
●If the cleaning pin does not pass through the
hole in the nozzle, clean with the cleaning
drill.(not included as a standard accessories).
●Check the condition of the solder plating on
the nozzle tip.
●Check visually if the nozzle was eroded.
CAUTION
The inside hole and the surface of the nozzle is plated with
a special alloy. Should this alloy become eroded by high-
temperature solder, the nozzle will not be able to maintain
the proper temperature.
●If the nozzle is still in a good condition, put
some fresh solder on the nozzle tip to protect
solder plated area from oxidation.
CAUTION
If the cleaning drill is forced into the nozzle, the drill bit
could break or be damaged.
Please use the proper size cleaning pin or cleaning drill for
the nozzle diameter.
• If the cleaning pin and cleaning drill do not
pass through the hole in the nozzle, replace
the nozzle.
• If the solder plating on the nozzle tip is worn,
replace the nozzle.
• If the inside hole of the nozzle is eroded,
replace the nozzle.
NOTE:
Unfortunately, it is often difficult to observe this condition.
Therefore, if desoldering efficiency goes down and all
other parts appear to be OK, the nozzle is probably
eroded and should be replaced.

15
Cleaning the inside of suction pipe
Move the nozzle cartridge to the cleaning
position indicated in figure at right. Change the
position of the nozzle cartridge before turning
the power ON, to prevent accidents.
To clean the inside of the suction pipe, ensure
that the solder remaining in the pipe has been
completely melted.
For the cleaning of the suction pipe, set the
nozzle temperature to 400°C/750°F or higher.
Start this cleaning after the set temperature has
been reached.
To clean the inside of the suction pipe, insert
the cleaning drill fully into the suction pipe
while turning it clockwise. Then remove the
accumulated debris.
Check and clean the front and back
holder bushings
If foreign matter gets stuck on the contact
surface between the front holder and the filter
pipe assembly, or between the back rubber
holder bushing and the filter pipe assembly,
air will be sucked into the tool, preventing
normal desoldering. Remove the solder and
flux adhering to the surface of front holder
and back holder then connect the filter pipe
assembly.
or
a
b
Nozzle
unlock
button
CAUTION
First remove the nozzle
from the grip while
pressing the nozzle
unlock button, then
insert the nozzle as
shown.
CAUTION
If you insert the drill
without turning it or if you
try to insert the drill at an
angle, the nozzle cartridge
may be broken.
CAUTION
When removing the cleaning
drill, keep it parallel with
the nozzle. If it is difficult
to remove the drill, turn it
slightly whilst withdrawing
it. If you forcibly remove the
drill, the cartridge may be
broken.

16
Checking and replacing the ceramic
paper filter
The filter is clogged with hardened
flux.
Fit the filter case cover in place.
1. Turn the filter case cover on the HAKKO
FM-204 station counterclockwise to
unlock it, then remove the cover by pulling
it straight out.
2. Replace the ceramic paper filter.
3. After replacing the ceramic paper filter,
press the filter case cover with its tabs
inserted into the corresponding slots in
the filter case then turn clockwise to lock
it.

17
Cleaning the pump
WARNING
Unplug the power cord before cleaning the
pump.
NOTE:
Consistent replacement of dirty/clogged ceramic filters
will reduce or eliminate the need to clean the pump.
1) Disassembly
1. Remove the screws (8) used to secure the
cover, and remove the cover.
2. Remove the screws (4) used to secure the
pump assembly.
3. Remove the inner hose and pump head (at
two locations).
2) Cleaning the pump head
●Remove the valve and guard, and clean
away any adhering flux.
CAUTION
If the guard is difficult to remove, heat it with warm air.
Do not try to force it off using a screwdriver or other
tool.This may deform the guard and reduce its air
leakage efficiency.
CAUTION
Clean with alcohol or thinner.
NOTE:
• Replace the valve if it is deformed or has
calcification.
• Replace the exhaust filter if dirty.
3) Assembly
●Attach the valve and guard.
CAUTION
When assembling the pump, be sure that it is airproof
and that there are no air leaks.
When attaching the valve and guard,
be sure to align the projections on
the pump head with the grooves on
the valve and guard.
Pump head
Valve
Valve guard

18
● Checking procedure
WARNING
Unless otherwise specified, perform the following steps after turning the power switch OFF
and disconnecting the AC plug.
Checking the electrical continuity of the cord
assembly
1. Remove the plug of the cord assembly from
the station.
2. If the handle is attached, remove it.
3. Remove the nozzle cartridge. For this removal,
see “Attaching and replacing the nozzle
cartridge.”
4. Remove the screws for the grip and measure
the resistance between the socket terminal
and the connector pin as shown below (refer
to the wiring diagram).
Plug 1 .......... Red (socket) 3
Plug 2 .......... Green (socket) 1
Plug 3 .......... Black (socket) 2
Plug 4 .......... Brown (LED circuit board)
Plug 5 .......... White (thermistor)
Plug 6 .......... Blue (switch circuit board)
If the resistance is larger than 0 Ωor ∞in any
location, replace the cord assembly.
1. Measure the resistance between plug pin 2
and the nozzle end.
2. If the resistance value exceeds 2 Ω(at room
temperature), perform the maintenance for
the tip, which is described in the next page. If
this does not decrease the value, check the
electrical continuity of the cord assembly.
■Checking the cord assembly
1
3
2
1
4
7
2
8
5
6
3
Plug
Switch circuit board Blue
White
White
LED circuit board
Green
Black
Red
Brown
Thermistor
Socket
<Wiring diagram of MODEL FM-2024>
■Checking the grounding line

19
■Maintenance
■Checking the heater/sensor
This procedure, if followed daily, will materially
add to tip life.
a. Set the temperature to 250°C (482°F).
b. When the temperature stabilizes, clean the tip
and check the condition of the tip. If the tip is
badly worn or deformed, replace it.
c. If the solder plated part of the tip is covered
with black oxide, apply fresh solder, containing
flux, and clean the tip again. Repeat until all
the oxide is removed, then coat the tip with
fresh solder.
CAUTION
NEVER file the tip to remove oxides!
d. Turn the power OFF and remove the tip, using
the heat resistant pad. Set the tip aside to
cool.
e. Remaining oxides, such as the yellow
discoloration on the tip shaft, are not harmful
but, can be removed with isopropyl alcohol.
Measure the resistance between
this pointand the heater/sensor.
Measure the resistance at room temperature
(15 to 25°C ; 59 to 77°F). The normal range is
8Ω±10%. If the resistance is outside this range,
replace the nozzle assembly.