Hitachi YUTAKI Series - Page 191

189
Troubleshooting procedure
SMGB0066 rev.0 - 12/2009
Troubleshooting
Service Manual
7
 
11

• ThealarmcodeisdisplayedonthePCB´sdisplay.
– This alarm code is displayed when the water inlet temperature thermistor is short circuited or cut.

Are the connectors between
PCB1 and PCB2 correctly
connected?
PCB1
CN9-CN1
PCB2
CN5-CN2
CN6-CN3
CN2-CN4
No
Yes
Pull out connector
and measure thermistor
resistance.
Isresistancecorrect?
No
Replace thermistor
Yes
Is connector CN9 on PCB2
correctlyconnected?
No
Yes
Wiringcheck,Repair.
(Breakingofwire,wrongwiring)
Wiringcheck,Repair.
(Breakingofwire,wrongwiring)
Check PCB1 and PCB2


Temperature (ºC)
Thermistor
Resistance (kΩ)



note
Measure the resistance at least in 2 different points which the temperature is different more than 10 ºC. -