Blaupunkt B32A122T - no power

[chabregas2k]

Hi everyone.

I have the above mentioned set for repair, and can find any of the power rails.
Being a beginner, i could use a hand pointing to where i should start looking.

Searched the web for a schematic, but didnt find one... aparently, there's a bunch of different boards with this number on them.

Thanks in advance for yout time.
Only thing i tested was the mosfet under the heatsink with the multimeter for shorts and on/off operation.


Toni

[dick_barton]

Re: Blaupunkt B32A122T - no power

What DC voltage do you have when you connect you meter leads to each side of the main capacitor EB1. Be carefull. The voltage can be around 380V dc so do not let the probes slip.

Have you checked the fuse FB1 alongside the mains in connector?

[chabregas2k]

Re: Blaupunkt B32A122T - no power

Hi again Barton.

Forgot to mention, but yes, checked the fuse

Voltage on Big cap 330V

Thanks for your time

Toni

[dick_barton]

Re: Blaupunkt B32A122T - no power

What dc voltage do you have on UF11 pins1 to 8. Pin 1 is next to the white arrow and the pin numbers increment going anticlockwise around the IC.

The only information I have found on this board is that the EEPROM UF11 can corrupt.

[chabregas2k]

Re: Blaupunkt B32A122T - no power

1 and 2 vary between 0.2 and 1.2 up and down... 3 to 8 nothing.

[dick_barton]

Re: Blaupunkt B32A122T - no power

If UF11 is a W25Q32BV EEPROM then pin 8 is the supply voltage and should be between 2.7V to 3.6V dc

[chabregas2k]

Re: Blaupunkt B32A122T - no power

If i keep the probe at pin 8... mostly 0, then every 2 seconds or so i get a spike to almost 1v, but instant drop to 0 again.

[dick_barton]

Re: Blaupunkt B32A122T - no power

If it's not getting the supply voltage then it's not likely to be an EEPROM problem but a supply voltage problem as you initially suggested.

What is the part number of UD11 & UD42

Is there a burn mark on the white patch by LD12

[chabregas2k]

Re: Blaupunkt B32A122T - no power

UD11 - FR9886
UD42 - GG3E

cant notice any burn marks

Thanks again, barton.

[dick_barton]

Re: Blaupunkt B32A122T - no power

What dc voltage do you have on pins 2 and 3 of the FR9886,

[chabregas2k]

Re: Blaupunkt B32A122T - no power

Both oscilating... cant get a fixed reading. input varies between 2 and 5 up and down.. pin 3 i get spikes and 0 like the reading on pin 8 of the flash.

[dick_barton]

Re: Blaupunkt B32A122T - no power

With the power to the set switched off can you do a diode test on dual diode D8101


Another thread with a similar board gives the voltages as given on the board
Are there any voltage points given on your board and if so what are the readings.
https://www.badcaps.net/forum/showthread.php?t=42022

[chabregas2k]

Re: Blaupunkt B32A122T - no power

DB101 looks good....

Thanks for your pacience

[chabregas2k]

Re: Blaupunkt B32A122T - no power

Sorry for being so long.

Tested every test point and the results are the same. 0 everywhere with the exception of the spikes every 2 seconds... as if the system is trying to come up, but something is shutting it off.

[dick_barton]

Re: Blaupunkt B32A122T - no power

What is the resistor value of the one above RB111

Can you lift the black heatsink so as to see the components underneath.

How did you test the mosfet and what is its part number given on it.

[chabregas2k]

Re: Blaupunkt B32A122T - no power

I tested the mosfet with the multimeter.. the basic open close / charge discharge test.

RB148 reads 0.4Ohm

Mosfet is MDF7N60B

When taking the pics for you, i found RB108 to be "funny looking" so i measured it to 8.7kohm (onboard). Should read 22 Ohm am i right??

Thanks for all your time once again!

[chabregas2k]

Re: Blaupunkt B32A122T - no power

The diode on the left, next to the inverter plug, shows continuity both ways, as its twin neighbor reads normal. did i struck oil?



Since theyre working in paralell, for testing purpose, it should work with the shorted on pulled out right? or should i replace before testing?

[dick_barton]

Re: Blaupunkt B32A122T - no power

If a diode shows continuity both ways (when at least one leg is lifted from the board) then you have struck oil and it is faulty.

[chabregas2k]

Re: Blaupunkt B32A122T - no power

Going to put all back together, replace the bugger, and get back to you.
Thanks for your patience teaching me. I promise i dont need to hear the same thing twice.

Ill post results later

[dick_barton]

Re: Blaupunkt B32A122T - no power

What is the diode number written on it?