Bosch Aquastar SMV65M00GB/44 no power or display

[johnboy183]

Dave can you explain this in laymans terms for me –
“the coil is a transformer

if the chip is not oscillating then its dc and transformers need ac”

[electrofix]

yes its the same as my pic above

Dave

[electrofix]

still makes sense change the chip and see what happens

Dave

[johnboy183]

Dave can you explain what you said below in layman’s terms for me –
“the coil is a transformer
if the chip is not oscillating then its dc and transformers need ac”?
I have now also removed the door sensor and no matter how I try to test it using a magnet I can get no response on the multimeter for rither continuity oir resistance. I expected it to be a reed switch but it is a hall effect triac when I look at the small board in it so no idea how to see if that is working to eliminate it beyond the magnet test I have done!
If this sensor is indeed failed (as it appears) it seems a big coincidence that the power board failed at exactly the same moment with not a single sign of failed or burnt components on the board and no dry joints or broken traces. Will look further into this tomorrow before starting to un-solder smd’s from the board and replacing them.
Thanks again for the ongoing advice – its much appreciated.
John

[electrofix]

transformers
https://www.explainthatstuff.com/transformers.html
the power supply that feeds the chip is 300v dc and the chip changes it to ac

did not know door switch was hall effect but it would not stop the unit powering up. as its powered by the mains with door open or closed you can hear a few noises from the pumps and things. since yours is dead you wont get that. you cant test it with a meter

stop looking for problems that might not be there. you have power in but no power out of the transformer. to cure this you can do one of 2 things. 1 replace the board. 2 try changing the chip in the hope thats the problem

Dave

[johnboy183]

You are absolutely right Dave I am always looking in too much depth instead of trying the simple first! Have ordered a tny so will report back when fitted. Thanks again.
John

[johnboy183]

Hi Dave
The TNY chip is expected tomorrow but I thought best to carry out checking the other components as far as possible in case there is a failed component elsewhere on the board.
There are four of these blue suppression caps on the board and two are identical – and of one capacity. The other two are identical but with a different capacity. Therefore I pulled all four to test and compare against their twin component.I drained all 4 caps before measuring and measured all off the board.
Two are B81122 Y2 MKP/SH and read identically as 23nF so happy they seem ok.
The other two are B32922 X2 MKP/SH but one of these reads 13.7nF and the other reads 183nF – almost 14 times more in value.
Looking at various specs and datasheets I cant get a definitive capacitance quoted to know which is right.
Any ideas gratefully received as to whether either of these are faulty and could be causative – or resultant – of the power outage on the board. The one with the 183nF is connected via various traces to both the frequently burnt out 100 ohm resistor and also to the TNY 264GN chip.

[electrofix]

those caps are just supression
as i said above if they fail it will go bang
they will be fine
dont look too deep

Dave

[johnboy183]

Hi Dave
Chip arrived today and now fitted. At first when switched on no high or low voltages at all! Then I bridged the two on/off pins on the board and turned board on at wall socket and the board fired up with 328v on the high and 14v on the low cap side of the circuit. disconnected the bridge wires and this time the board showed the correct voltage when switched at wall. Very happy at this point as many of the output connectors also showed 14v or 5v so went ahead and re-installed the board in the washer and after reconnecting everything pressed the on/off switch and display all lit up as normal with the buttons functioning as they should,
However if I go to start the machine, or just leave it powered on, it goes from displaying the 2:45 time for the cycle to display E06. This error seems on this machine to be door switch/ sensor failure (if you recall I said earlier I thought this hall effect sensor was not responding to magnet when closing door). Further testing of the sensor with a separate magnet gets no activation of the sensor. Even if I bridge out the sensor it still gives exactly the same E06 error so I think there may be a fault on the board with this sensor trigger.
So back to the drawing board (but at least have the board working in the main!). Any thoughts on what next to look at on the board to pin this down?
But thanks anyway for getting me to persist in changing the chip -you were very right to do so.
John

[electrofix]

[johnboy183]

Thanks for the reply. Is the above applicable to the SMV65M00GB/44 which I have as there are so many conflicting bits of documentation on this E06 fault on the web? If so do you measure with the connector disconnected from the switch sensor?
Thanks
John

[electrofix]

this is from a bosch manual that uses the same hall effect sensor in the door. have not got exact manual as they are impossible to get but this is as close as it gets
she4am12u go onto manualslib and look for service manual of this
Dave

[johnboy183]

Thanks Dave.
After much measuring and delving The following has emerged:
1) The contacts on the board for the door switch sensor showed 13.7v on the output and 0v on the return (with or without the switch leads connected).
2) At the switch connector the reading on both leads was 0v. After much investigation I found that the terminal U clips that attach to the board connectors for these two leads were not clamping onto the contacts at the board end – hence the lack of voltage. Took off the bar of connectors at the board end and many of the clips were very open (?age ?heat). So compressed all the clips on this long connector to what they should have been to rectify any poor connections for other components.
3) Re-testing at switch connector now showed 13.7 v on one and 0 v on other. Bridging these connector clips (as if switch had made circuit) and remeasuring showed voltage on circuit reduced to 0v.
4) Error E06 remains constant no matter what I have tried so far.

Given the information you provided above I suspect some item on the board to be faulty in terms of the door switch sensor
I have also ordered a switch sensor as I also suspect that given I cant get any Hall effect tests to get the sensor to react.
Any thoughts?
John

[electrofix]

all you can try is the sensor and see what happens

Dave

[johnboy183]

Ok thanks
John

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