Magnavox 32mf231d no picture or sound

[raymond]

The backlights come on and the green led lights and stays on. The power rail to the main board (bottom right near light blue cap) starting with red reads 16.3, 16.3, 24.1, 6.7, 4.2, 0, 0, 0, 1.2, 0.
I've replaced the 3 larger caps (2 dark blue and 1 light blue) on the power board. They were swollen and commonly go on this board. Please help with what to try next. Cheers.....Ray

[budm]

Re: Magnavox 32mf231d no picture or sound

Please see the PS diagram, see if it matches yours, and tell me what you see on the connectors on the left side of the diagram, it will a lot easier for me to troubleshoot the problem.
It sounds like you have problem in the main board.

[budm]

Re: Magnavox 32mf231d no picture or sound

Service manual:
What is your chassis number?

[raymond]

Re: Magnavox 32mf231d no picture or sound

Hi, I'm quite sure it's the same board, looking at the second diagram in the pdf. you've shown me. In referring to your second reply question ....If you're asking for the voltages on the 12 pin connector to the inverter....they are 24, 24, 24, 24, 24, 6.7, 4.1, 0, 0, 0, 0, 0.
I hope I haven't misunderstood your question. .......Ray

[budm]

Re: Magnavox 32mf231d no picture or sound

OK, at least the power supply is OK and it does send the Inverter on to turn on the backligts, but some how there are other failed parts in the main board that cause the lost of the pictures and sound.
We need to check voltages on the main board first, starting at the 3-pin regulator first.
Can you please take good clear pictures of the main board as a whole, and then 1/4 section pictures of board so we can see good closed up pictures? The service manual does not give good pictures.

[raymond]

Re: Magnavox 32mf231d no picture or sound

Here are new pics and a close-up of a possible problem (my guess anyway).

[budm]

Re: Magnavox 32mf231d no picture or sound

I think you have found the problem with that blown part. At this point, just to be sure we have the correct service manual for this chassis, can you get the chassis number for this TV, the part is blown up and I cannot see the complete P/N on it. The link for the service manual is for 37" but yours is 32" so I want to get the correct information. It looks like a switching regulator IC.
Follow-up:
I look at the 37" version service manual, the IC is for the 12v buck regulator P/N L5973.

[raymond]

Re: Magnavox 32mf231d no picture or sound

Hi budm
First of all........Thank you very much for your generous help and your time.
I've been trying to download the pdf manual but it keeps shutting down the download at 3.7mbs ........... I'll keep trying. I think you've identified the right part #.
I've included one more close-up of the part. I scraped the swollen area off, it was like dry crumbly soot but unfortunately the rest of the id number is gone. I'm far from understanding how to read these electronic diagrams but I'm trying. Cheers....Ray

[budm]

Re: Magnavox 32mf231d no picture or sound

I believe that is the correct part number as shown the scaler bd PDF as I have onpost #7you can see that the coomponent designators match your picture. The IC deisgnator is 7003, the inductor desigantor is 5001, Diode 6001 also matched.
I am not sure about the download problem.

[raymond]

Re: Magnavox 32mf231d no picture or sound

I did finally manage to get the pdf manual. I try to find a 'L5973' locally. It looks like a delicate bit of soldering as well.

[budm]

Re: Magnavox 32mf231d no picture or sound

Cut the legs off the IC first, then it will be easier to remove the legs off the board.

[raymond]

Re: Magnavox 32mf231d no picture or sound

Ah........ yes. Great idea. Thanks

[miguelon69]

Re: Magnavox 32mf231d no picture or sound

Did you ever fixed your tv by changing the chip?

[budm]

Re: Magnavox 32mf231d no picture or sound

????? What kind of question is that?

[miguelon69]

Re: Magnavox 32mf231d no picture or sound

let me explain , i have the same tv with the same board ,and on mine the same chip ic7003 is blown out ,my power supply is ok and i wanted to know if they found a solution.for this problem. thanks for your help

[budm]

Re: Magnavox 32mf231d no picture or sound

We are still waiting for raymond to tell us what happen after he replace the IC.

[thejollyroger]

Re: Magnavox 32mf231d no picture or sound

i dripped a bit of soder onto the mosfet
fried the main board. anyone know where to find a replacement cheap?

[Dgtech]

Re: Magnavox 32mf231d no picture or sound

let me explain , i have the same tv with the same board ,and on mine the same chip ic7003 is blown out ,my power supply is ok and i wanted to know if they found a solution.for this problem. thanks for your help

Are you able to read the component markings on top of your chip? He wasn't able to read his.

[Dgtech]

Re: Magnavox 32mf231d no picture or sound

There are two of these mainboards on ebay. One is $38 and the other is $85. Search for ( 3138 103 6284 ).

Good luck.

[drpj23]

Re: Magnavox 32mf231d no picture or sound

L5973D works from digikey.

Replaced it and everything seems to be working for now. Just be careful for there is an exposed pad on these SOICs.