Goodmans LD3265D2

[tom66]

Re: Goodmans LD3265D2

That is normal for that lead to be missing on that diode. It's part of the manufacturing process.

[newtothis]

Re: Goodmans LD3265D2

Yeah I noticed that once I got the new one.

Will attempt a repair on the old board one of the days.

[newtothis]

Re: Goodmans LD3265D2

Ok so the tv was good for a while... Then came back the fault... It has gotten worse of time reoccurring more often to the point now that the blasted thing won't turn on....

Now... If I leave it unplugged for say a week it will work first time then slowly get worse again.

Any ideas?

I can use a multimeter to basic level... Check polarity, check voltage, ohms, capacitance. I have ordered an ESR meter which I should have in the next 14 days so I can properly check the caps.

How do I go about testing diodes etc and how exactly would I go about fault finding?

Thanks

[Clydeuk]

Re: Goodmans LD3265D2

Is it a new or salvage power supply you've fitted? The PW26 I've found is one of the more robust Vestel supplies, but they are suffering with poor quality components etc. I know the PW25 was a horror for self destructing, seemed the UF5401 diodes shorted, I believe there was probably something out of spec on the primary that led to the failure. The PW26 is a better supply but evidently yours isnt happy somehow

[newtothis]

Re: Goodmans LD3265D2

It was a salvage, worked fine to start with though then progressively worsened

[Clydeuk]

Re: Goodmans LD3265D2

Dare I suggest bad caps lol

[newtothis]

Re: Goodmans LD3265D2

There are no bulges and all caps read out ok on the multimeter... But until I test their ESR values I won't know. I know that d881 diode is a common fail, it's a BYV27-200... Data sheet here :

On diode setting on my meter it reads .467 , it is closed in reverse reading giving infinity... Is this diode good or bad?

[tom66]

Re: Goodmans LD3265D2

That's a good diode.

[newtothis]

Re: Goodmans LD3265D2

Thanks Tom

Ok I will wait til I have my ESR meter then go through the circuit one thing at a time testing them.

[newtothis]

Re: Goodmans LD3265D2

Tom I noticed on another thread you told someone how to test the three legged components attached to the heatsinks... Whatever these are called... Can you just let me know what they should read under testing?

[tom66]

Re: Goodmans LD3265D2

They are diodes, or MOSFETs, maybe. How about a picture?

[newtothis]

Re: Goodmans LD3265D2

Pointing the screwdriver at the sucker

[tom66]

Re: Goodmans LD3265D2

What is part # on it then?

[newtothis]

Re: Goodmans LD3265D2

Sorry for the late reply,

I did a bit more reading and managed to test the other diodes and mosfets using my DMM. They turned out fine. After testing the outputs from the psu I noted that the 24v was only pushing 16v... So I tracked back through the circuit and found three parallel smt resistors that were knackered... They read 3k instead of 300k, they are R817 R818 and R819 on the circuit side of the PSU. Replaced all three and set now works fine.

Thanks for your help

[tom66]

Re: Goodmans LD3265D2

Nice one. Which side -- primary mains side or secondary output side -- were they on?

[newtothis]

Re: Goodmans LD3265D2

Secondary side Tom.

I'll put some pics up soon with info so if anyone else encounters the same issue they can take a look.

Well considering I knew nothing at all about electronics 4 months ago I don't think I've done too bad.

[newtothis]

Re: Goodmans LD3265D2

for some reason i cannot edit my above post.

corrections - The SMD resistors are supposed to have read 612k.

[retiredcaps]

Re: Goodmans LD3265D2

corrections - The SMD resistors are supposed to have read 612k.

It is kind of odd for a resistor to read lower. They generally fail open or higher than their rating. Nevertheless, good job on the repair.

PS. I found a few blown SMD resistors on the cheap $5 multimeters.