37pd5200e smps

[paulstef]

Re: 37pd5200e smps

You plug the TV set in and it makes BOOM right away?

Or you plug it in it goes to standby then you turn it on and then it makes BOOM?

[zx81]

Re: 37pd5200e smps

I can only get a standby green led solid on when I remove the cable that goes to to the io board.

The fireworks started as soon as I connected all the other boards to the power supply. Popped in the cable but as soon as I pressed the power button Bang

Luckily I orderd 2 set of resistors and an extra Mosfet.

[tom66]

Re: 37pd5200e smps

Same resistors shorted?

[zx81]

Re: 37pd5200e smps

Yes Tom same one.

[tom66]

Re: 37pd5200e smps

Sorry meant, same FET shorted? Did you replace the driver IC at same time?

[zx81]

Re: 37pd5200e smps

Yes Tom same FET. Initially I did not change or check the driver IC picture uploaded in post#19. Since the bulb across the fuse went off when I replaced The MOSFET. I thought it would be safe to fire up with the fuse back in place.

Done some very basic testing of the driver IC. No obvious shorts. Will try and reflow in the next day or so when my Atten reflow station arrives and pop it back in.

I just realised that I haven't tested Q003 and Q004 in the PFC section as suggested by Paulsef in an earlier post. Will check too.

Could a short in any of the other boards cause the issues I'm having?

[tom66]

Re: 37pd5200e smps

A short in the other boards should not matter.

I always, always replace the driver, regardless of apparent damage or not, even if it tests OK. Reason is, when the FET shorts, it basically shoves 300V DC into the 15V output of the IC... who knows what kind of damage that could do? It might not damage the output but instead some other parts of the IC, like control logic.

I also usually replace nearby SMD resistors at the same time.

[zx81]

Re: 37pd5200e smps

Cheer Tom.

Will let you know how I get on.