Hakko Electronics FX-951 User manual

First Edition: March 31, 2007
[ For FX951-51 -up ]
Service Manual
TABLE OF CONTENTS
Revision History
Chapter 1 Inspection Flow Chart
Chapter 2 Procedure and Method of Repair
2-1 Checking the Exterior
2-2 Checking the Power Supply Line
2-3 Checking the Interior
2-4 Voltage Application Check
2-5 Iron Holder Check
2-6 Inspection after Repair
Chapter 3 Exploded Drawings and Parts List
3-1 Exploded Drawings
3-2 Station Parts List
Chapter 4 Disassembly Procedure
4-1 Opening the Cover
4-2 P.W.B. (for Control/Connector) and Front Panel
4-3 Power Receptacle, Power Switch and Transformer
4-4 Jack
4-5 Iron Holder
Chapter 5 Wiring Diagram
Warnings, cautions and notes are placed at critical points in this manual to direct the
operator’s attention to significant items. They are defined as follows: Please read the
following sentences and understand them sufficiently before reading the main text.
Cautionary points during use
▲WARNING: Failure to comply with a WARNING may result in serious injury or death.
△CAUTION: Failure to comply with a CAUTION may result in injury to the operator, or
damage to the items involved.
NOTE: Indicates the items which operators are likely to make a mistake in and
should pay attention to.

Revised date: March 9, 2012
Revision History (FX-951/FH-200)
Revision History
Revision Date Information Revised Description Approved by Created by
March 31, 2007 - First edition Hirai Nishii
March 9, 2012 3-2 Station Parts List Change the part number
for Receptacle.
B3076 → 699-031236
Nagase Nishii

First Edition: March 31, 2007
1 Inspection Flow Chart (FX-951/FH-200)
Chapter 1 Inspection Flow Chart
図16
Iron Holder Check
Section 2-5
Checking the Power Supply Line
Section 2-2-(5)(6)
Checking the Power Supply Line
Section 2-2 (1)-(4)
Checking the Interior
Section 2-3
Voltage Application Check
Section 2-4
Checking the Exterior
Section 2-1
Inspection after Repair
Section 2-6

First Edition: March 31, 2007
2-1 Checking the Exterior (FX-951/FH-200）
Chapter 2 Procedure and Method of Repair
2-1 Checking the Exterior
Check the exterior for the following points.
(1) Are the case R and case L damaged?
If the case R and case L are damaged:
Replace each case.
(2) Do the four operation buttons and card operate smoothly?
If operations are not smooth:
Installation of the P.W.B. (for control/connector) is faulty, or the P.W.B. itself is faulty.
Install the P.W.B. again or replace the P.W.B. (for control/connector).
(3) Does the receptacle allow smooth insertion and removal?
If the receptacle does not allow smooth insertion or removal:
Replace the P.W.B. (for control/connector).
(4) Are the rubber feet of the case R and case L chipped or damaged?
If the rubber feet of the case R and case L are chipped or damaged:
Mount a new rubber feet or replace them.
(5) Take out the fuse from the power receptacle and check that the fuse has not blown.
Check the rating of the fuse with reference to the table on the right.
If the fuse has blown:
Replace the fuse.
If the wrong fuse has been used:
Replace the fuse.
Rubber feet
Card insert slot
Receptacle
Power switch
Operation buttons
Hitch a tool
into this slot
and take out
the fuse.
Voltage Fuse rating
100V-110V 250V-2A
220V-240V 250V-1A
Rating
seal
Power
receptacle
Case R Case L
Jack

First Edition: March 31, 2007
2-2 Checking the Power Supply Line (FX-951/FH-200)
I: Measure across the ground line.
II, III: Touch the plug with the tester probe as shown in
the photo and measure at two positions on the station
side indicated by arrows.
2-2 Checking the Power Supply Line
Check the power supply line for the following points.
(1) Has the sheath on the power cord been dropped or damaged?
If the sheath on the power cord has been dropped or damaged:
Replace the power cord, as it may break eventually.
(2) Measure the resistance values of the power cord
at three points using a tester.(Photo on the right)
NOTE The cord is normal if resistance values are “1Ω
or less”.
If a resistance value is abnormal:
Replace the power cord.
(3) During measurement in step (2) above, twist and bend the power cord at various angles
(including the plug and the station connecting part).
If abnormal resistance values are detected:
The line is broken. Replace the power cord.
(4) Turn on the power switch and measure the resistance value between power receptacle
pins.
NOTE Under normal conditions, the resistance values are as listed in the following table.
(resistance values of the primary side of the transformer)
If the resistance value is different from the value in the table above:
The power switch or the transformer is faulty. Proceed to steps (5) and (6).
If the resistance value is within the above range:
Proceed to section 2-3.
100V 5.6Ωto 6.8Ω
110V 6.0Ωto 7.4Ω
120V 6.5Ω～9.5Ω
220V 30.9Ωto 37.7Ω
230V 30.4Ωto 37.2Ω
240V
Measure the value
between these
power receptacle
pins.

First Edition: March 31, 2007
2-2 Checking the Power Supply Line (FX-951/FH-200)
NOTE Remove the case R before taking the following steps.
(5) Measure a resistance value of the power switch using a tester.
NOTE With the power switch turned on, the switch is normal if a resistance value is “1Ωor
less”.
If a resistance value is abnormal:
Replace the power switch.
(6) Check the resistance on the primary side of the transformer as follows.
Measuring points: Between the soldered parts of the power switch and the power
receptacle on the primary side of the transformer.
If a resistance value is abnormal:
Replace the transformer.
Be sure to turn the
power switch on for
measurement.
100V 5.6Ωto 6.8Ω
110V 6.0Ωto 7.4Ω
120V 6.5Ω～9.5Ω
220V 30.9Ωto 37.7Ω
230V 30.4Ωto 37.2Ω
240V
Measure the resistance between the pin
(1) on the power switch side and the
center pin on the power receptacle side
(as shown by the arrow).
Lead wires from
the primary side
of transformer

First Edition: March 31, 2007
2-3 Checking the Interior (FX-951/FH-200)
2-3 Checking the Interior
Remove the cover and check the internal components for the following points:
(1) Measure the secondary voltage (ACV) of the transformer with the power turned on.
If the measured voltage is different from the values of the above table:
Replace the transformer.
(2) Check the surface of the P.W.B. (for control/connector) visually.
If abnormalities such as cracks and explosions are found on the components:
Replace faulty components.
If portions around the cracked or exploded components are burned:
Replace the whole P.W.B.
(3) Are the transformer and P.W.B. (for control/connector) correctly mounted?
If the parts are not installed correctly:
It may result in a failure. Mount the parts correctly.
(4) Is insulation on the lead wires damaged?
If the insulation is damaged:
Replace the damaged lead wires.
(5) Are there any failures in any of the soldered lead wires?
If a soldered section is faulty:
Repair each section.

CAUTION Wear a wrist strap when following these procedures to prevent damage to the P.W.B.
100V
AC 24.3V to 29.7V
110V
120 V
220V
230V
240V
Measure the voltage
while touching the
tester to this section.

First Edition: March 31, 2007
2-4 Voltage Application Check (FX-951/FH-200)
2-4 Voltage Application Check
Perform a voltage application check.
NOTE Without attaching the iron, perform a check with the following procedures.
(1) Check the soldering iron error.
1. Turn on the power switch.
2. The following indications appear on the display in the order presented, and the
buzzer keeps beeping.
3. Turn off the power switch.
If no indication appears on the display:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
When an indication appears on the display but it does not function properly:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
NOTE Connect the iron (without the tip) and check according to the following procedures.
(2) Check the sensor errors.
1. Turn on the power switch.
2. The following indications appear on the display in the order presented, and the
buzzer keeps beeping.
3. Turn off the power switch.
If no indication appears on the display:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
When an indication appears on the display but it does not function properly:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
NOTE Connect the iron (without the tip) and check according to the following procedures.
(3) Check the LCD.
1. Insert a card.
2. While holding down the four operation
buttons, turn on the power switch.
3. After the version No. (ex. [001]) is
displayed, the segment of the indicator
[Left] will be lit sequentially.
NOTE The figures to be displayed vary
depending on the version of P.W.B.
8. 8. 8. C - E
→Flashing
[Left]
3rd digit
[Right]
1st digit
[Center]
2nd digit
[UP]
[DOWN]
[*]
[#]
8. 8. 8. 3 5 0
→S - E
→
(The example shows a
setting at 350◦C.)
Setting temperature Flashing

First Edition: March 31, 2007
2-4 Voltage Application Check (FX-951/FH-200)
4. After [UP] is pressed, the segment of the indicator [Center] will be lit sequentially.
5. After [DOWN] is pressed, the segment of the indicator [Right] will be lit sequentially.
6. After [*] is pressed, [4] will be displayed in the center.
7. After [#] is pressed, figures around [769] will be displayed. (only when setting
temperature (°C))
8. After [#] is pressed, [6] will be displayed in the center.
9. If the card is pulled, [888] will be displayed.
10. Turn off the power switch.
If the unit does not operate correctly:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
NOTE Connect the iron (with the tip) and perform a voltage application check using
the following steps:
(4) Check the setting temperature.
Setting temperature range
In Centigrade 200°C to 450°C
In Fahrenheit 400°F to 840°F
1. Turn on the power switch with a card detached.
2. The following indications appear on the display in the order presented, and the tip
temperature rises to the setting temperature.
NOTE When the tip temperature reaches the setting temperature, the buzzer will sound
and the heater lamp at the lower right of the panel will start to flash.
3. Insert a card. Indicator [Left] flashes.
4. Press [UP] and [DOWN] to check that the indication changes within the temperature
setting range.
5. Indicator [Center] flashes if you press [*]. Press [UP] and [DOWN] to check that the
indication changes within the temperature setting range.
6. Indicator [Right] flashes if you press [*]. Press [UP] and [DOWN] to check that the
indication changes within the temperature setting range.
7. Press [*] to return to usual operations. The tip temperature rises to the setting
temperature.
8. Measure the tip temperature. (Check that the tip temperature is at the setting
temperature plus or minus 15°C.)
If the unit does not operate correctly:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
If a tip temperature does not reach a temperature range:
The tip has degenerated or an offset value is incorrect. Replace the tip or correct
an offset value as described in step (5) below and check a tip temperature again.
8. 8. 8. 3 5 0
→3 5 0. →
(The example shows a setting
at 350°C.)
Setting temperature
Heater lamp
Tip temperature

First Edition: March 31, 2007
2-4 Voltage Application Check (FX-951/FH-200)
(5) Check the offset value.
Input range for the offset value
In Centigrade -50°C to + 50°C
In Fahrenheit -90°F to + 90°F
1. Hold down [#] for one second or longer to make the indicator [Left] flash, indicating
“0” or “-”.
2. Press [UP] and [DOWN] to check that the indication changes alternately between [0]
and [-].
3. Indicator [Center] flashes by pressing [*]. Press [UP] and [DOWN] to check that the
indication changes within the input range.
4. Indicator [Right] flashes by pressing [*]. Press [UP] and [DOWN] to check that the
indication changes within the input range.
5. Press [*] to return to usual operations.
NOTE If an input range of offset values is exceeded, the operation returns to the
beginning.
If the unit does not operate correctly:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
(6) Check the parameters.
1. Turn off the power switch before inserting the card.
2. If turning on the power switch while pressing the [UP] and [DOWN] at the same time,
the mode will change to the temperature scale setting.
•Check that pressing the [UP] and [DOWN] changes the indication alternately as
follows:
3. Pressing [*] accepts the indicated setting and proceeds to the “Power save setting”.
•Check that pressing [UP] and [DOWN] changes the indication within the input range.
NOTE Check the power-save operation according to the procedure in Section 2-5: "Iron
Holder Check “
1 C 1 F
Temperature scale setting
C Centigrade (°C)
F Fahrenheit (°F)
Power save setting
0 ＯＦＦ
1 to 29 Indicates “SLP” after the set time has elapsed.
30 Indicates “---” after 30 minutes.
2 0 2 1 2 3 0
* The above example
shows the case when it
is set to 1 min.

First Edition: March 31, 2007
2-4 Voltage Application Check (FX-951/FH-200)
4. Pressing [*] confirms the indication, and the “Low Temperature Alarm Tolerance
Setting” is indicated.
•Indicator [Left] flashes. Press [UP] and [DOWN] to check that the indication changes
within the input range.
NOTE Every time [*] is pressed, the indication will be determined and the flashing
indicator will be shifted from [Center] to [Right].
5. Pressing [*] accepts the indicated setting and proceeds to the “Supervisor/operator
Control Setting”.
•Check that pressing [UP] or [DOWN] changes the indication alternately as follows:
6. Pressing [*] finishes the parameter setting and returns the unit to the normal
operation.
If the unit does not operate correctly:
The P.W.B. is faulty. Check the P.W.B. using the procedure in step (7).
NOTE Perform the following inspection if the unit does not operate in steps (1) to (6).
(7) Visually inspect the reverse side of the P.W.B. (for control/connector) for faulty soldering
or pattern exfoliation.
If a faulty portion is found:
Correct soldering.
If a pattern coming off is found:
Replace the whole P.W.B.

CAUTION If a fault is not found visually, replace the whole P.W.B. (for control/connector).
1 5 0
(Example of indicating 150°C)
Temperature
indication
Input range of low temperature
alarm setting
°C 30 to 150
°F 50 to 300
4 0
4 1
Supervisor/operator control setting”.
0 Card is required for offset value entry
1 Offset value entry is allowed without card

First Edition: March 31, 2007
2-5 Iron holder check (FX-951/FH-200)
Iron receptacle
Tip holding spring
Holder for iron receptacle
Iron holder base
Cleaner base
Stay
Switch case
assembly
2-5 Iron Holder Check
Check the following points of the iron holder.
1. Are any of the rubber feet (4 feet) lost or damaged?
If lost or damaged:
Replenish or replace the rubber foot with a new one.
2. There are 11 screws in total securing the iron holder.Are any screws lost?
If lost:
Replenish the lost screw with a new one.
3. Check whether the connecting cable is broken.
NOTE Measure the resistance values in sections A and B. If each resistance value is “1Ω
or less”, the unit conditions are normal.
If the resistance value is ∞:
The connecting cable is broken. Replace the connecting cable with a new one.
A
B
Check the resistance values in the 2 sections Aand B.

First Edition: March 31, 2007
2-5 Iron holder check (FX-951/FH-200)
4. Insert the connection cable into the iron holder and check the following points:
•Does the stay operate smoothly?
If the stay does not smoothly operate:
The iron holder base may be deformed, the spacer may be lost or the spring in the
switch case may be damaged.
Check each point and correct or replenish and replace it.
•Measure the resistance of the connection cable to check that the switch operates
normally.
NOTE If the resistance value is “1Ωor less” when the tip is placed on the soldering holder
base and the resistance value is “4.7kΩ±10%” when the tip is released from the
iron holder, the unit conditions are normal.
If the resistance value is abnormal:
Replace the switch case assembly with a new one.
5. Connect the connecting cable to the iron holder and FX-951 and then check the
power save function.
NOTE If the connecting cable is not inserted fully into the jack, the power-save function
will not activate.
If the power-save function does not operate normally:
Replace the P.W.B. with a new one.
Apply tester here to measure.
If the resistance value is “4.7kΩ±10%”
in this condition, the unit conditions
are normal.
If the resistance value is “1Ωor less”
in this condition, the unit conditions
are normal.
Power save setting
0 ＯＦＦ
1 to 29 Indicates “SLP” after the set time has elapsed.
30 Indicates “---” after 30 minutes.

First Edition: March 31, 2007
2-6 Inspection after Repair (FX-951/FH-200)
2-6 Inspection after Repair
Perform the inspection after repair.
<Preparations>
W-I tester / DMM (Tester) / Power meter (or ammeter) / Thermo-couple
thermometer (HAKKO192)
(1) Voltage application test
Resistance between power receptacle ground terminal and receptacle pin 2 (for
measurement point, refer to the photo) is 1Ωor lower.
Resistance between power receptacle ground terminal and IRON 2 receptacle pin 2 is 1Ω
or lower.
(2) Insulation test and withstanding voltage test
[Insulation test]Apply 500VDC and check that the value is 25MΩor higher.
[Withstanding voltage test] Apply 1250VAC (1mA) to check that it can resist for 1 second or
longer.
NOTE Perform the following inspections with a proper tip.
(3) Check the power consumption.
Power consumption must be 75W ±10%.
(4) Measure the tip-to-ground potential and the tip to ground resistance.
The tip-to-ground potential must be 1mV or lower.
The tip to ground resistance must be 1.0Ωor less.
(5) Check the temperature.
The tip temperature must be at the setting temperature ±15°C.

CAUTION If an accessory iron is provided, return it to a customer with lead-free
solder put on the tip. (To prevent oxidation)
Pin 2: Center at bottom
Power receptacle
grounding
terminal

First Edition: March 31, 2007
3-1 Exploded Drawings (FX-951/FH-200)
Chapter 3 Exploded Drawings and Parts List
3-1 Exploded Drawings
A
B
C
D
E
F
G
H
I
J
K
L
M
1 2
3
N
O
P
Q
R
S
T
U

Revised date: March 9, 2012
3-2 Station Parts List (FX-951/FH-200)
3-2 Station Parts List
No. Category Part name Specifications Product No. for each voltage
100V 110V 120V 220V 230V 240V
A Sales Front panel B2973
B Sales Button set B2982
C Sales P.W.B. for control For control and connector B3256
D Sales Case L
With rubber feet/cushion
rubber A
(Refer to Photo 4-1-5 to
4-1-7)
B3255
E Sales Case R
With rubber feet/cushion
rubber B
(Refer to Photo 4-1-5 to
4-1-7)
B2978
F Sales Transformer B2979 B2983 B2836 B2984 B2985 B3067
* The transformer 230V forAustralian plug is B3067.
G Sales Power switch B2852
H Sales Fuse B2403(250V-2A)- B2987(250V-1A)
I Sales Power cord
Rubber 2-pole grounding B2387 - - - - -
Vinyl 2-pole grounding B2419 - -
Vinyl 3-conductor CH
plug - - - B2436 - -
Without vinyl 3-conductor
plug - - - B2421 -
Molded BS plug - - - - B2422 -
Molded BS plug CE B2425
European plug - - - B2424 - -
European plug CE - B2424
Australian plug - - - - B2426
J Sales Card B2972
K Sales Power receptacle B2666
L Sales Grounding plate B2227
M Sales Connecting cable B3253
N Sales Iron receptacle With screws B3001
O Sales Tip fixing spring B2791
P Sales Holder for iron
receptacle B3248
Q Sales Iron holder base With rubber feet B3251
R Sales Cleaning sponge A1536
S Sales Cleaner base With rubber feet B3249
T Sales Stay B3250
U Sales Switch case
assembly B3252
* Sales Rubber feet
Two feet for FX-951
station
(Refer to Photo 4-1-5 to
4-1-7)
B2016

Revised date: March 9, 2012
3-2 Station Parts List (FX-951/FH-200)
No. Category Part name Specifications Product No. for each voltage
100V 110V 120V 220V 230V 240V
1
Repair Holder B3073
2
Repair Only receptacle
Please let us know the following
part number
when ordering.
699-031236
3
Repair Jack
PJ-35N
With nut
B3329
*
Repair Cushion rubber A For case L
(Refer to Photo 4-1-5 ) B3086
*
Repair Cushion rubber B For case R
(Refer to Photo 4-1-6 ) B3087

First Edition: March 31, 2007
4-1 Opening the Cover (FX-951/FH-200)
Chapter 4 Disassembly Procedure
4-1 Opening the Cover
(1) Loosen 5 screws on the sides of the case R to remove the cover.
●
Assembly procedures (opening)
(1) Install the front panel in the case L. (Fig. 4-1-3)
NOTE Install the red lead wire and the lead wire for jack (white) carefully so that they do not
get caught.
NOTE Run the lead wire of P.W.B. (for control) outside the boss.
(2) Install the grounding wire for the P.W.B. in the designated place. (Figs. 4-1-3, 4-1-4)
(3) Install the lead wires for transformer, power switch and power receptacle outside the boss.
(Fig. 4-1-3)
NOTE Run the grounding wire not to let it come in contact with the power receptacle terminal.
(4) Cover the case L with the case R and secure them with 5 screws (P tight round head screw
M3 × 16) (Figs 4-1-3, 4-1-5 and 4-1-6)
NOTE Check that the cushion rubber B is installed in the case R and the cushion rubber A is
installed in the case L.
(5) Check that 2 rubber feet are installed in each of case R and L. (Fig. 4-1- 7)
Fig. 4-1-1
Case R
Fig. 4-1-2
P.W.B. (for control)
Power switch
Transformer
Front panel
Case L
P.W.B. (for connector)
Power receptacle
4-1-4
Fig. 4-1-3
Assembly procedure (2)
Install the lead wire of the
P.W.B. in the depressed
section in the case.
Assembly
procedure (3)
Run all the lead
wires for the
transformer, power
switch and power
receptacle outside
the boss.
NOTE Be careful
not to let the
grounding wire
come in contact
with the power
receptacle terminal.
Assembly procedure (1)
Install the lead wire of the
P.W.B. (for connector)
outside the boss.
Assembly procedure (1)
Be careful not to let the red
lead wire of the P.W.B. get
caught on the front panel.
Lead wire for jack (white)

First Edition: March 31, 2007
4-1 Opening the Cover (FX-951/FH-200)
Fig.-4-1-
7
Rubber feet
Two rubber feet are installed for each case.
Cushion rubber
B
Fig 4-1-
6
Cushion rubber A
Fig. 4-1-
5
Case L Case R

First Edition: March 31, 2007
4-2 P.W.B. (for Control/Connector) and Front Panel (FX-951/FH-200)
4-2 P.W.B. (for Control/Connector) and Front Panel
(1) Follow the procedures 4-1.
(2) Disconnect the connector for jack from the P.W.B. (4-2-1)
(3) Desolder 2 soldered sections at the secondary side of the transformer. (Fig. 4-2-1)
(4) Disconnect the grounding wire for P.W.B from the grounding plate. (Fig. 4-2-1)
Note The grounding wire for P.W.B. is attached together with the grounding wire for jack.
(5) Remove 4 screws and then disconnect the P.W.B. for control from the front panel. (Fig. 4-2-2)
(6) Remove 4 screws and then disconnect the P.W.B. for connector and holder from the front
panel. (Fig. 4-2-3)
(7) Remove 2 screws and disconnect the buttons R and L. (Fig. 4-2-3)
Four screws securing the P.W.B. for control
Fig. 4-2-2
Fig. 4-2-1
Secondary side of transformer
Grounding plate
Front panel
The grounding wires for
P.W.B. and jack are
attached together.
Connector for jack
Fig. 4-2-3
Two screws securing the buttons R and L
Four screws securing the P.W.B. for connector
Reference photo
If the 4 screws are
removed, the holder in
the photo at left will be
removed.