Miele km5951

[mblguy]

Re: Miele km5951

Okey guys, i managed to keep the cooker. my parents bought a new one but i still really want to fix it because i believe it should be quite simple and not as expensive as a new one (1200 euro's). After i write this i am going to put it back together and test if it is one single cooker that is broken or if it is the whole system. until i have result. here are the pictures you guys asked for:
The front left board
The front right board
The controller board (for the buttons)
The total picture with the cover removed

[diif]

Re: Miele km5951

Have you checked the bridge rectifiers and IGBT transistors for shorts ?
They are the components at the bottom in photos 1 and 2.

[mblguy]

Re: Miele km5951

Hmm the rectifiers van be easily checked but how Do i check igbt's?

[stj]

Re: Miele km5951

same way - look for shorts between the pins.

[mblguy]

Re: Miele km5951

Okey guys, today i checked some things.
At first, all the hubs make short circuit so it is not only one cooker.
Then i took the multimeter and checked the igbt's and rectifiers. I noted that the bottom left igbt and the rectifier from the bottom right board are both doing weird things. The igbt is completely shorted out and the rectifier does not rectify accordingly. I hope this clarifies some thing for you guys.

Thanks for the help so far. I really appreciate it and like that we already got so far.

[budm]

Re: Miele km5951

Remove and retest the suspected devices that were tested shorted in the circuit.

[mblguy]

Re: Miele km5951

Hey guys sorry it has been so long. I tried removing the units but my soldering kit was too weak. It didn't melt nicely so i had to get a better one. Now i managed to get the solders away nicely but i have to get the units out of that heatsink. they are reaally tight. How can i bend open the limbs of the heatsink so i can remove the units without crushing the whole board?
hope there is some sneaky trick i did not know about.

nice evening to you all.

[diif]

Re: Miele km5951

They look to be held on with three metal clips. Remove the clips and the IGBTs should just be resting on the heatsinks

[mblguy]

Re: Miele km5951

Yeah i see, but there seems to be a lot of stress on them, so i am scared to break them or the components.

[budm]

Re: Miele km5951

Remove the whole assembly out and you should be able to slide the clips out, they fit into the groove of the heatsink. Do not bend the clips' fingers too much, it will lose its tension.

[sam_sam_sam]

Re: Miele km5951

You may need to heat the pins of the IGBT and put a little pressure on that pin that you are heating until that pin moves then go to the next pin just do not put to much pressure on any one place

You may need to repeat this a couple of times before the ITGT module comes free

One very important thing to keep in mind do not get in a hurry when you do this you can make a real mess of the board if you do

If you have a heat gun station that has temperature control and air flow control put the smallest tip that you have blow the heat on that pin ( do not use to much air flow) and do things that have above with one difference move the pin until around unit the board solder cool down where pin dose not stick to the board

One note do not leave the heat gun tip in one place or you will burn the board and lift the pin right off the board