Dead Samsung DTB H260F

[maybenever]

Re: Dead Samsung DTB H260F

Top Left = 73RT
N05A

Top Center = M39100
1.8W716

Bottom Rt = K1A
78D05F
715
Also, I missed a wire in the top wiring harrness, there is a wire marked 5v, and find no voltage there. I find no fuse markings.
Sorry

[jetadm123]

Re: Dead Samsung DTB H260F

Top Left = 73RT
N05A

Top Center = M39100
1.8W716

Bottom Rt = K1A
78D05F
715
Also, I missed a wire in the top wiring harrness, there is a wire marked 5v, and find no voltage there. I find no fuse markings.
Sorry

I would suggest that you turn the power board over and try tracing the path of the 5V from the wiring harness pin to hopefully one of the caps in question.

[bluto]

Re: Dead Samsung DTB H260F

Here is how you fix this:

1. Replace ALL caps on the power supply. (Digikey part numbers in the other thread) Less than $10 shipped. I don't like the looks of the 2 Samxon 1000ufs (the one next to the VREG heatsink bulged on mine).
2. Failing that un-solder one leg of each resistor on the power supply and check for proper resistance. Replace any that are open or significantly wrong resistance.
3. If all resistors check ok, then check all of the ICs, Voltage regulators, diodes, transistors, etc. for shorts. Consult with badcaps.net for replacement advice.
4. Failing that you could have a problem with the power supply control IC (the 8 pin deal between the two transformers) or a bad transformer. PWM IC could probably be replaced, transformers could be more trouble to find a replacement.
5. There is no step 5.

[maybenever]

Re: Dead Samsung DTB H260F

Update, when I was testing voltage at the lowerwiring harness, I had the boards disconnected. When I connect them together, I have no voltage at the any pin.
Thanks for all the help.

[maybenever]

Re: Dead Samsung DTB H260F

I've ordered all new caps, will replace and get back.
Thanks All

[maybenever]

Re: Dead Samsung DTB H260F

Caps came in today, replaced all of them, box powered up and works perfect.
Thanks to all, for your time and help. I took this box to 3 TV repair shops and no one would touch it. Now I'm looking for some books on basic electronics, I'll take any advice on that subject too.
Again, Thanks

[Agent24]

Re: Dead Samsung DTB H260F

Good work!

I became interested in electronics because of Dick Smith's 'Funway into Electronics' but I doubt you could easily find them in America.

I've heard 'Teach Yourself Electricity and Electronics' is good.
(http://www.amazon.com/Teach-Yourself.../dp/0071459332)

[bluto]

Re: Dead Samsung DTB H260F

Glad to hear that another DTB was revived. Its amazing that TV repair shops like that still exist. They could have gambled with 5 minutes of google time to find out that it was a 10 minute repair. And then pocketed at least $50 thereafter. Oh well, they can keep their 'professionals only' 'pay for access' repair tips sites to themselves.

[Agent24]

Re: Dead Samsung DTB H260F

Yeah, but, If they give out their repair tips free, everyone will repair the stuff themselves and they won't get any money.

Though if THREE of them turned down the repair then that's their problem.

My local repair shop repaired my Akai amplifier for me.. but then declined to repair my CRT monitor on the basis that "They didn't have an oscilloscope fast enough"

I told them it was geometry fault, which could be fixed upon hitting the monitor and which was probably a dry solder joint.

I asked if they wouldn't mind just resoldering anything that looked suspect (I didn't feel comfortable trying to discharge the tube etc myself), but they still didn't want to know. Their loss, I guess.

Maybe I will try repairing it myself one day...

[maybenever]

Re: Dead Samsung DTB H260F

Thanks again Agent24. I've ordered a couple of books, looking foward to learning a little. Until last week, you could write all that I knew about a PCB on the back of a postage stamp, never owned a soldering iron. I practiced on an old motherboard I had scarped out. That computer would occasionly restart on it's own, I see why now, it had 3 very domed up caps on it.
I'll continue to read posts and learn.

[Agent24]

Re: Dead Samsung DTB H260F

Motherboards can be a bit tricky, I would recommend learning to solder well on a normal single layer board first.

If you just bought an iron, make sure you use it properly.

Keep the tip clean and tinned so it doesn't corrode and become useless. Never file the tip, or you'll take all the plating off.