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GFWR4805F2MC GE Front Load Washer - No lights on UI board yet the board has 14.5 and 9v supply present.

BBatteiger

Premium Member
Joined
Oct 28, 2020
Messages
2
Location
VA
Model Number
GFWR4805F2MC
Brand
GE
Age
1-5 years
Washer died mid load. Noticed all lights out on front panel and door unlocked. However water still in basket. I can not turn on the washer anymore. No LED or message at all on UI board. I checked the voltage that comes from IMC board to the UI board and for the 12v I measure 14.5. For the 7.5v I measure 9v.

I was concerned that maybe the supply voltage was too high or noisy, so I powered the UI board from bench top supplies at 12 and 7.5 and it still would not do anything except make a slight single click each time it is powered up. I would not think this would be normal for UI board. I would think you should be able to power it up on its own and get some sort of LED lights and error code for loss of IMC card (since it would not be connected in this case). However, I am a bit concerned to just replace the UI board if the higher voltage from IMC is what might have damaged the UI board. But I do not want to replace IMC card if the designers just thought 14.5 and 9v was close enough to what they said it should be.

Has anyone checked these voltages on working machines or tried to power up the UI board on its own to see if that is a test for that board?

Thanks,
Brian
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
114,572
Location
McMullen Valley, Arizona
Hi Brian,

I know on the GE dishwashers the UI Board should get 13.5 volts DC and most members report 14 volts DC and the new UI Board always fixes them. Now yours are a bit higher, but I'm not sure if that's high enough to make a difference or not, I'm interested as well to see what other techs or members are getting on theirs. I have not worked on this model as of yet or I would tell you myself.

Here's the UI Board for your model:
WH12X25837 Pcb Ui Asm


Here's the main control board for your model:
WH12X26034 Pcb Imc Asm and S/w


Jake
 

BBatteiger

Premium Member
Joined
Oct 28, 2020
Messages
2
Location
VA
Hi Jake,
Thanks for the quick reply. I have the matching dryer of this washer and got the idea that maybe they share some design standards. Sure enough it has two boards inside also, but there are many more connections between the boards. However the dryer also has a 12v and 7.5v supply shown on the control board which runs to the UI board. I measured those and they were 12.5v and 7.6v. So much closer to expected values. It looks like both of these appliances use a TOP252-262 power supply IC to control the low voltage power. My thought is that maybe since this is a PWM power supply with feedback which looks at average voltage and might not see all the noise that might not be filtered out by the electrolytic caps, maybe I would just try to pull some off and test them. I tested 4 so far and they are OK per capacitance meter...darn...

However, I am still shocked that I get nothing from powering up the UI board on the bench with a good set of power supplies. Would they really design a UI board that would not display an error code and instead display nothing if it can not talk to IMC?
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
114,572
Location
McMullen Valley, Arizona
That's a good question, but I don't know the answer to it.

Lets see what others say that have run into this issue on theirs.

Jake
 
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