Whirlpool Main Control Board

[hotshot]

I have a Whirlpool ADG7540/1 which is not heating the water. A repair engineer told me that the heater and thermostat were OK and it needed a new main control board, although he didn’t actually open the door housing to examine the main control board.

After he left I removed and reconnected all the connectors onto the main control board and amazingly the heater worked on the next wash. However the fault has now returned. Not sure whether it’s a dodgy connector or something intermittent on the PCB.

To help me investigate further, can anyone tell me what these letters mean on the control board connector sockets:

HEW
MS
DS
WI
SPM
DPM
WV1
DDDR
WV2
NTC
FM

Control board is UCB-ICFD-P5-A2 (Flextronics)

[gegsy]

Re: Whirlpool Main Control Board

Hi
If a fault is apparent it will be displayed by a sequence of lamps in conjunction with an audible beep. Have you witnessed this at all?

Greg

[hotshot]

Re: Whirlpool Main Control Board

Can’t say I’ve noticed lamps flashing or an audible beep. It is an integrated appliance, so the lamps are not visible when the door is closed, but I think I would have noticed when I opened the door to check if the water was hot. Will check again tonight.

Does the control board have diagnostics to detect that no current is flowing to the heater? Is that why you are asking if there are flashing lamps?

The washing cycle does not abort, it just runs through as normal – except that the water is not hot.

After it ran cold last night, I waggled a few control board connectors and it worked OK again after that. I suspect a dodgy connection somewhere. May be one of the connectors or perhaps a dry joint or broken track on the control board which is affected by waggling the connectors. This is why I was looking for info about the connector marking codes, so that I can focus on the ones to do with heating (e.g. heater, thermostat).

[Dave_Conway]

Re: Whirlpool Main Control Board

Unless the PCB is faulty, the heater not working would display an error.

Other possible is the NTC is faulty or a poor connection there (NTC connector on the PCB).

Power off when checking please :zap:

Dave.

[hotshot]

Re: Whirlpool Main Control Board

Can anyone tell me what NTC stands for (and also any of the other acronyms listed in my original post)? Thanks.

[kwatt]

Negative Temperature Co-efficient Thermistor. 😉

K.

[hotshot]

Re: Whirlpool Main Control Board

Cool :). Do you happen to know what the “normal” voltage across the NTC would be? Presumably it should change as the water heats up.

Anyone know what any of these stand for?

HEW
MS
DS
WI
SPM
DPM
WV1
DDDR
WV2
NTC (Negative Temperature Co-efficient Thermistor)
FM

[kwatt]

We can’t give you that detailed information (even if we had it) or Whirlpool could sue us and, if you fry yourself, your relatives could sue us.

Welcome to the politically correct nanny state. 😉

K.

[gegsy]

Re: Whirlpool Main Control Board

hotshot wrote:Cool :). Do you happen to know what the “normal” voltage across the NTC would be? Presumably it should change as the water heats up.

Anyone know what any of these stand for?

HEW
MS
DS
WI
SPM
DPM
WV1
DDDR
WV2
NTC (Negative Temperature Co-efficient Thermistor)
FM

The advice we give is to guide you into hopefully resolving a particular fault you may have. The information regarding module markings above are of no relevance to your fault at this time hotshot.
If you think you may have an NTC fault on your appliance, the usual giveaway is when you select any prog, immediatly after you have closed the door an audible tone will be heard constantly. This can however be poor communication between NTC and module.
Hope that helps.

Greg

[gegsy]

Re: Whirlpool Main Control Board

Hya Ken :wave:

Greg

[hotshot]

Re: Whirlpool Main Control Board

Thanks for you help so far. I realise that there are limits on what you can say.

Faulty NTC was Dave_Conway’s suggestion. Not sure myself, as that is not one of the connectors I wiggled last night to get things working again (I think it was HEW, MS and DS).

I don’t get any beeping when selecting a programme and closing the door. The programme starts up and runs through as normal – only problem is water is cold at all times!

[gegsy]

Re: Whirlpool Main Control Board

I would check HEW connection if I were you 😉

Greg

[DentedPorsche]

Re: Whirlpool Main Control Board

Normally, no heat and no error code is a module fault.
The module can check the components but it can’t check itself.
Looks like the original diagnosis may well be correct.

DP

[gegsy]

Re: Whirlpool Main Control Board

After it ran cold last night, I waggled a few control board connectors and it worked OK again after that. I suspect a dodgy connection somewhere

I still have me money on poor connection.

Greg

[hotshot]

Re: Whirlpool Main Control Board

I have taken the module out and examined it. It does look like the HEW is the output to the heater. This output comes from directly from the contacts of a relay in the module. I have checked the continuity at the relay terminals (with the heater lead connected) and it is fine. I suspect the relay is faulty, i.e. it is failing to switch correctly (most of the time). There is a suspicious rattling noise from the vicinity of the relay when you shake the module.

By the way, I don’t see how the module can detect a faulty relay because there are no current sensing components between the relay terminals and the edge connector of the module.

[Author]

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