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Dishwasher went kaput tonight. Wife said it crackled and then switched off.
Looking at the control panel it’s clear that something went up in smoke around the area of ST16 and ST17. I’m not sure if a component such as a resistor lived in that area as there appears to be a couple of pads where the centre of the scorching happened but they also appear to be connected.
Took the bottom off and the base was wet but I couldn’t see any signs of leaks or water on any components/wiring.
I suspect that there may be a short somewhere but without a circuit diagram finding it is going to be a challenge.
Does anyone know where I can get a service manual or circuit diagram from? (I thought Miele used to put them in a plastic bag behind the door panel. Had a quick look but couldn’t see anything)service manual wont show you circuit board components
if you want to post clear pics of the board we can have a look
if pics are over 2M you will have to host elsewhere and post a link
Dave
Thanks Dave – I was thinking more along the lines of the downstream components that plug onto the board rather than the actual PCB circuit diagram.
It looks like whatever ST17 connects to could be the issue.there is a lot of black on the plug which i would not expect
whats the back of the board like ?
Dave
I’ve seen worse!
Plugs cleaned up OK but on plug ST17 Pin 2 and 3 where it contacts on the component side of the board they appear to have melted but back side of the board look ok. Not sure what that connects to because it’s not giving a proper reading. ST16 Pin 1 in the harness is intact as are all others. ST16 Pin 1-2 reads 1-2ohms – again no sure where it goes in the loom but ST16 Pin 1 and ST17 Pin 3 appear to be on either sides of one of the power relay switches.
Sorry to clarify. The plug contacts the board on both sides as it’s double sided. The plug contacts on the side that connects to the tracks on the component side appear to have melted so only stubs remain (about half length). The plug contacts on the side that connects to tracks on the non components side are intact. Hope that makes sense. The plug shells are intact
makes sense there has been some current flow or the plug has got wet, the edge of the pcb is charred
think I would take the base off and with a meter on buzz see if i can find where the wires might feed
Dave
Yeah job for the weekend I think. If the main board has gone and another major component it’ll be heading landfill. Honestly thought Miele would last much longer. This one was a replacement for one that failed beyond economical repair at 6 years old. It’s 8 years old but I had to replace the pump two years ago because an oring failed and you can’t buy the o-ring so a £2 bit requires a £400 replacement, a pipe split a year ago and now this. Oh well
Thanks for your help Dave.So buzzing out the ST17 Pin 2 and Pin 3 show that they connect to the incoming mains with Pin 2 = L and Pin 3 = N.
There’s what I believe is a noise suppression capacitor across the incoming main that I can’t really test. I’d expect it to read somewhere between 100k and 1.5M but it’s OC on the 2M range (my DVM max and no cap test).
If this dishwasher is like other Miele dishwashers (and I think it is) the incoming main taps off to the door switch and the heater (possibly pump too). Noticed the door switch is short circuit (door closed) but can’t work out yet where that’s triggered. I did however notice that the cable is snapped that leads to the ratchet mechanism on the side which I assume is the auto open.
I think the heater is fine at about 30Ohms.
Ran out of time to check the pump – job for tomorrow.starting to think that plug has got wet and gone with a bang
i would put a 3 amp fuse in the plug and see if it powers up
assume the fuse on the board is ok and there is no other visible damage on the board
Dave
electrofix wrote: starting to think that plug has got wet and gone with a bang
It’s possible although not obvious when I took it apart
electrofix wrote:i would put a 3 amp fuse in the plug and see if it powers up
I’ll check for shorts on the motor tomorrow (I think the motor and heater are the only things capable of drawing enough power to melt the contacts but I’d expect them to fail before the mains deleted the board) and if I find nothing then I’ll give that a go but i think I’d need to fix the ST17 plug temporarily due to the melted contacts. Long term – assuming it works – I’ll need to replace ST17 plug and rebuild the track on the PCB, maybe adding an SMD fuse for safety.
electrofix wrote:assume the fuse on the board is ok and there is no other visible damage on the board
To be honest I can’t see any obvious fuses on the board. All looks like diodes, resistors, capacitors and ICs. The rest of the board is in mint condition – what you see on the first picture is the extent of the damage on the board.
No – they are all intact (1-2 ohms)….thought you meant on the power line. Those fuses are downstream i think (again guesswork without hours of point to point buzzing out), I was looking for a higher power fuse ….the fact the tracks burnt out is making me look for the powerline short but i think your suggestion around water leak may be the solution
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