WT741/2P F05 Error but replaced pump and Pressure Switch

[andyg]

My WT741/2P started with error F11 so I replaced the pump and checked that there were no blockages ANYWHERE! Then started getting F05 error, so replaced the Presuure Switch.

I'm still getting F05.

Checking for dodgy wiring i noticed the mains supressor filter is black/burnt on the live terminal and the connector melted. But the machine still is working. The wires are still connected so power is getting through. I'm getting fed up chasing my tail with replacement parts.

So the question is - if it's getting power surely the pump would be receiving power too. Would replacing this part also be a waste of time. Obviously if i can find where the fault is with the pump not powering up it would need replacing.

Anyone shed any light on this and have any other things for me to check?

Already checked all hoses, the tube to the pressure switch, the connectors to the pcb, checked for burning on the pcb.

The original pump did burn out, i could see burning on the coils and i tested the new and old one by wiring them up in the garage.

Thanks in advance.

[Whitegoodshelp (Andy)]

Any burned connection needs fixing asap or it could start a fire. Potentially a poor connection could cause behaiviour problems. Have you read my article on Hotpoint error code F05?

[andyg]

Thanks for the reply Andy

I've just taken the pcb out and a found blackened board, bottom left connector. Seems to be the connector that gets a signal from the pressure switch. In my frustration ive broken the green board with chips and capcitors on it etc

Think it's time to throw the towel in and buy a new machine.

Out of interest why can't i replace or shouldn't replace the pcb? I read something about it needing programming? Have i got this right?

I have found pcb's on ebay for £30 - not that i'm going to buy one.

[Whitegoodshelp (Andy)]

Replacing a pcb has always been something I discourage because so many people misdiagnose it and they fit one only to find the fault remains. The pcb can be very expensive and you can't send them back so it's just too much of a gamble. Even if you see something is definitely "blown" on the pcb - you can't be sure it wasn't blown by something and the same might happen to a new one. Then you have the added problem of al lot of them needing configuring although new ones may come with configuration instructions.

[Whitegoodshelp (Andy)]

Some "blackened" areas may well be obvious faults, but there is almost always some "blackened" parts on a pcb, usually near a capacitor that gets hot when running. This can easily be taken for burning when it's often just a soot-like build up and not indicative of a fault.