Dead '06 Samsung TX-R2035 TV

[radiotvnut]

Someone brought me the above mentioned Samsung TV for repair and it was one of those deals where it worked fine one night and was dead the next morning. After doing some checks, I found that the switching power supply appears to be inoperative and I can't find any shorts on the secondary side of the power supply. The only service information I found was a high priced photocopy of the original factory manual from Sam's.

Playing around in the dark, I replaced the switching IC (CQ0765RT). Of course, that didn't fix it; so, I checked everything around the power supply (capacitors, diodes, and resistors) and I can't come up with anything wrong. After I take a break from it, I'm going to recheck things in case I overlooked anything.

Would anyone happen to have the service information for this TV?

[Dangler]

Seems like there were several threads or posts about bad caps in the newer Samsungs that caused them to not turn on. You might do a little searching and see what you come up with.

[radiotvnut]

Bad caps are common in the LCD models. This is a CRT TV and all caps in the PS check fine.

[radiotvnut]

I may be on to something. I found a transistor in the power supply (2SC815, NTE289A) to be leaky. I'll replace that and see what happens.

[radiotvnut]

OK, I was on to something; but, there's still something else that I need to be turned on to. I replaced the defective transistor and guess what, the damn power supply still won't start. The only other things to check is the optoisolator IC and a KA431CZ (NTE999) voltage regulator IC. This is one example why I dislike solid state equipment because, unlike tubes, semiconductors can be very unforgiving. With solid state, all it takes is for one part to fail and it starts a chain reaction.

[ctc17]

Pull the transformer and ring test it

[radiotvnut]

I replaced the other parts I mentioned and a did a ring test on the transformer (good). The POS still won't power up and I'm about to give up on it. It never fails, let someone approve a nice estimate and the POS is going to turn into a dog that refuses to be fixed. Now, I've wasted a bunch of time on this garbage and won't likely make anything off of it.

I swear, I need to simply stop taking in everyone's shit for repair. I've got enough of my own that needs fixing.

[radiotvnut]

Forget about this one. I got tired of finding too many good components; yet, no power-up. I called the owner, gave him the bad news; and, when he gave me permission to junk the TV, I had fun destroying it.