Neff dishwasher 750839

[chuffy]

Hi Guys,
Trying to obtain a Neff dishwasher power module part no 750839.
Out of stock at BSH for months.
Just posting this on the off chance someone might have one lying around.
cheers

[electrofix]

if you go on neff site it alllows you to purchase one as far as i can see

only says limited stock not no stock

try it yourself and query it. Would not be the first time manufaturers would hold back stock just for retail customers

Dave

[chuffy]

Hi Dave I’ve been phoning Neff on a weekly basis and there was nil stock in the U.K. and Germany.
Phoned again this morning and was told there was just 1 in stock in Germany.
This would have to be sent to the U.K. and then have to be programmed before being sent out to me which could another 2-3 weeks.
Don’t think the customer wants to wait any longer.

[electrofix]

whats up with the machine and the board you have ?

Dave

[chuffy]

Hi Dave,

Sorry only saw your reply.
The appliance is completely dead with no slight click from the power module relays when mains connected.
I have tried EMW and QER to see if they would have look at it but no luck.
I have replaced several of this type of module for the same fault.

Noel

[electrofix]

these board have 2 power supplys. one for stand by while its off and the other for when its in operation

if the primary power supply fails it will be completly dead. if the secondary power supply fails then i would expect the power relay to close and thats all

with your ear very close to the board press the on off sw and see if you can detect a very quiet click. if yes the primary circuit is ok and its a main power supply problem
also check the chunky 100 ohm resistor which is next to the power relay if this has blown the board may well be repairable

dave

[chuffy]

It’s been 3 months since I last saw the m/c and diagnosed the fault.
As far as I can remember it was completely silent on power up.
Like I said I spoke to EMW / QER and they were reluctant to try to repair saying it’s probably a power supply chip failure and they wouldn’t be able to repair.

Noel

[electrofix]

was looking at a board i have here trying to get an idea of how they work

as i said there has to be 2 power supplies. I can see the main one through a standard chip but that only comes on once the power relay has closed. The power relay has to get its power from somewhere but i would need a complete machine harness to try to understand it. The on off sw must energise this relay which in turn powers the board. Thats why i said you will need to listen hard as this relay will be quite quiet
spent an hour on it just for interest but will need a live one to go further

not sure why Qer reacted that way. if it was a simple chip change you would have thought it would be easy

Dave

[chuffy]

Hi Dave,

I’ve still not managed to obtain this part.
Many phone calls and emails and back to square one.
The customer is being very patient so I might just remove the module and send to QER just in case they can repair it.
Nothing to lose apart from a few quid postage etc.

Noel

[electrofix]

that makes sense

chip has blown and the resistor is a fusible type so act as a fuse

replace resistor and chip plus check diodes nearby

think i have a board in work in case you cant read the resistor. they are normally under 100 ohms 3w fusible

Dave

[chuffy]

Thanks Dave,

Don’t think I’ll be replacing any chips I have enough problems with relays and capacitors.

I’ll probably have a word with QER again.

Noel

[electrofix]

ok
let me know if they refuse

Dave

[chuffy]

I’ve messaged QER with photos and asking if they would attempt a repair.
Will let you know how I get on.
Noel

[chuffy]

Hi Dave update on this power module.
I sent it off to QER and called them a few days later for a status update.
Apparently they replaced several components but couldn’t get it to power up so it was scrapped.
Cheers.
Noel.

[electrofix]

ok thanks

you win some you lose some

Dave

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