16-07-2017, 10:37 PM
Our old washer (WMA66) was dying, main bearings making a din so loud I couldn't be in the house when it was running, remembering seeing plenty washers down my local scrap yard I went to have a look and found a newer model (2007 vs 2003) which I thought I'd be able to pillage the drum from, in order to fix the WMA66.
Upon inspection (after buying it, for a tenner) I found it was a washer drier, not just a washer and as such the drum would be unsuitable, so I did the next best thing and had a go at fixing it. Because space was limited in the house I was working outside and it appeared to work ok, but after 10-15 minutes the whole thing would go dead, and unless unplugged for 5 mins then plugged back in again it would refuse to start up. On the rear, at the lower left when viewed from the back is a small, flat cover which hides a 5 pin connector. I had my suspicions and removed the board, after some continuity testing I found it was an I2C port, connected to the main processor, an EEPROM and the front panel, and also the main +5v of the washer.
With the board removed and laying out the back of the washer (flapping in the breeze, importantly) it would run fine. With the board installed, it would switch off. I checked the +5v and sure enough that was going dead, which shouldn't happen as the PSU is always on, power-off is actually just standby.
Further testing with the board out suddenly prompted a failure to run with a code F-01 on the LED display where the remaining time would normally be. I couldn't get past this, unfortunately the suggestion for F-01 is that the motor controller is dead, and seeing that this has a 3-phase inverter drive running a brushless motor I thought it was dead for good.
After removing the board and checking all connections I couldn't shake the F-01 EVEN THOUGH THE MOTOR WOULD RUN!
I considered reading out the EEPROM with my programmer but guessed that it would be fruitless, reading 32kb of memory without any clue what I was looking for.
As a last resort I tried something else, instigating another fault. The list of faults codes for this washer suggests that F-13 would be flagged if the thermal sensor on the drier failed open or closed circuit, so I unplugged it and plugged the machine back into the mains.
Sure enough, F-13 displayed 10 seconds after power up and the machine would stop completely. So I powered down, plugged the sensor back in (which is located on the aluminium drier fan housing at the top of the machine) and then reapplied power.
BINGO! full operation restored. After I replaced all the smaller electrolytic caps on the board (there's a main link cap of about 400uF at 400V for the inverter which I didn't change) the machine now works just fine, has been performing well for the last week. I think the main culprit capacitor was a cheap, shonky 400v 22uF job which was the main filter cap for the TOPSWITCH SMPSU, it was the only cap rated for 85 degree C and is placed DIRECTLY above the hot heatsink.
Hopefully this information might help others fix a machine in future!
Dave.
Upon inspection (after buying it, for a tenner) I found it was a washer drier, not just a washer and as such the drum would be unsuitable, so I did the next best thing and had a go at fixing it. Because space was limited in the house I was working outside and it appeared to work ok, but after 10-15 minutes the whole thing would go dead, and unless unplugged for 5 mins then plugged back in again it would refuse to start up. On the rear, at the lower left when viewed from the back is a small, flat cover which hides a 5 pin connector. I had my suspicions and removed the board, after some continuity testing I found it was an I2C port, connected to the main processor, an EEPROM and the front panel, and also the main +5v of the washer.
With the board removed and laying out the back of the washer (flapping in the breeze, importantly) it would run fine. With the board installed, it would switch off. I checked the +5v and sure enough that was going dead, which shouldn't happen as the PSU is always on, power-off is actually just standby.
Further testing with the board out suddenly prompted a failure to run with a code F-01 on the LED display where the remaining time would normally be. I couldn't get past this, unfortunately the suggestion for F-01 is that the motor controller is dead, and seeing that this has a 3-phase inverter drive running a brushless motor I thought it was dead for good.
After removing the board and checking all connections I couldn't shake the F-01 EVEN THOUGH THE MOTOR WOULD RUN!
I considered reading out the EEPROM with my programmer but guessed that it would be fruitless, reading 32kb of memory without any clue what I was looking for.
As a last resort I tried something else, instigating another fault. The list of faults codes for this washer suggests that F-13 would be flagged if the thermal sensor on the drier failed open or closed circuit, so I unplugged it and plugged the machine back into the mains.
Sure enough, F-13 displayed 10 seconds after power up and the machine would stop completely. So I powered down, plugged the sensor back in (which is located on the aluminium drier fan housing at the top of the machine) and then reapplied power.
BINGO! full operation restored. After I replaced all the smaller electrolytic caps on the board (there's a main link cap of about 400uF at 400V for the inverter which I didn't change) the machine now works just fine, has been performing well for the last week. I think the main culprit capacitor was a cheap, shonky 400v 22uF job which was the main filter cap for the TOPSWITCH SMPSU, it was the only cap rated for 85 degree C and is placed DIRECTLY above the hot heatsink.
Hopefully this information might help others fix a machine in future!
Dave.
