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Hi,
Hotpoint WMUD9427P UK is playing up. The motor isn’t turning at all, no error messages, relay can be heard clicking at points when you’d expect drum to stop then start revolving again.
Drum is free spinning, no smell of burning from motor or visible damage.
It has no brushes from what I could see so assume it’s an induction motor or an electronic commutation brushless motor and the 5 transistors under a huge heatsink on the PCB are MOSFETs delivering current to the stator windings in turn and modulating that current with PWM?
Haven’t done voltage checks yet, only visually inspected the PCB and motor.
Just wondered if this is a common fault and the likely cause known, might help to know if it’s more likely the motor or PCB. I’m assuming PCB and will probe the transistors tomorrow if I get time.
Thanks
Re: Hotpoint WMUD9427P motor not turning
Is common and 99{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} the board. As for cause slugs are common but if you got no fried friends its likely its just failed.
As for what’s failed not sure on the new 3 phase boards.
Word of warning this boards hold quite a charge and must be left for at least 5 minutes after being turned off.
Re: Hotpoint WMUD9427P motor not turning
Little update:
removed PCB and checked it more thoroughly after very quick look the other night. One of the 6 transistors under the large heatsink is cracked and open-circuit. The related high voltage driver IC is reading differently to the other two which drive the other two pairs of MOSFETs, I’ll replaced that too (it’s on eBay from china for just a few pounds, although aliexpress would probably do them too if anyone ever needs hard to find parts).
First though, I need to remove the heatsink to find out what transistor I need to source and despite the family trade and my background being electronics repair, I don’t have a high enough wattage soldering iron for such a big heatsink so am awaiting delivery of a 100W one.
I’ll then check nothing else is wrong that could have caused failure of the transistor. In my experience MOSFETs used in similar applications fail simply from the hard life they have at high current and voltage, although the driver may have caused its failure.
I’ll update this when I know more, might help someone else and if a few quids worth of components can affect a repair rather than over £100 for a new board, it’s a winner.
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