Samsung Spn4235 No video or sound

[lilmonk3]

Re: Samsung Spn4235 No video or sound

hopefully those caps maybe your issue then hope you have better luck with the new set you have picked up for free.

Lets hope.. Just the short time I have been here, I have learned a lot about working on things... And thats because of all the great members here..

[TechShui]

Re: Samsung Spn4235 No video or sound

Techsui.. I was having the crazy readings myself. But its because the TV would shut off while I was testing..

Yeah, my TV shuts off at random too.

This TV is crazy I keep hoping I might turn it on and everything will be working. After all, it was working fine before, even with those bulging caps.... sigh.

The last time it shut off was last night when I was probing pin 15 (GND) of the PFC chip. I heard the usual buzzing or 'chirping', before the TV went off. This makes me wonder if touching that pin causes it to go into protection mode? But all the other times I heard buzzing noises, none of them resulted in the TV shutting off, so maybe this was a coincedence. I can't see any pattern in this TV's behavior.

No buzzing sounds here though

Do you mean you already probed the PFC (the 16-pin chip at location IC1) and there was no noise?

What were your voltages? Especially pin 13 (Vcc) of the chip, is it steady?

If you haven't tested it yet, be sure to use pin 15 of the same chip for ground. Although it can be awkward to measure small pins so close together with these probes.

I recommend using rubber gloves too. Since the chip is in the area between the big heatsinks.

[TechShui]

Re: Samsung Spn4235 No video or sound

Can anyone please help me find the service manual? ElektroTanya comes up empty.

This TV is still an enigma. I think it's showing me error codes.

I got a spark from one of the inductors, this was definitely my fault, as I was shifting the board with the TV plugged in.

In my defense, I thought it was unplugged And
I had been working on it all day and was very tired at that point.

The main fuse blew after the spark, I replaced it. And now this:

Solid red LED for 4 secs, then blinks 2 times (at an interval of 1/sec)
Then blinks faster (3 times/sec) red, orange, red, green, red, orange, red, green

Then blinks green continuously like it was doing a week ago, and just like then, I have to unplug to turn off.

OK, scribd search for "SPN4235", gives several results for PS42P3sx chassis service manual, could that be it?

http://scribd.com/search?category=&l...amsung+spn4235

My chassis does not match though, so I'm dubious. Here's my info:

Model: SPN4235
Type: AX42P3
Chassis: ALDC8 [ADFC12]

EDIT: After skimming the whole thing (only 39p, pretty small for a plasma with such a complex design) I believe it actually is the manual for SPN4235. Pages 36 - 37 are identical to PS schematic I have. So unless there's another model with the same PS board, this is the manual.

Very disappointing, A search for "error codes" brings up nothing. Skimmed the whole thing and it's devoid of any useful info, no troubleshooting steps, no LED codes. It doesn't even have diagrams of the other parts! (sustain boards, buffers, G and F drive, etc not there).

Is it possible this is a partial manual? or has samsung always been this skimpy in their service manuals?

[DavidOH]

Re: Samsung Spn4235 No video or sound

This one has your model listed.

http://www.scribd.com/doc/87090514/Samsung-Pdp4298ed-ET

[TechShui]

Re: Samsung Spn4235 No video or sound

Sorry to revive a dead thread, but I'm curious to know if lilmonk ever fixed her SPN4235? She said she was waiting on some capacitors she ordered... and I wonder how that turned out.

Hopefully she's subscribed to this.

I would also like to add, that I found a scorch mark near IC30 which is to the left of the upper green transformer in this pic: https://www.badcaps.net/forum/attach...2&d=1335460697

EDIT: The scorch mark was on the trace leading to the vcc pin, not on the chip itself, actually, it's closer to a 2.4k ohm resistor which also looks burnt.

[mine_us_3]

Re: Samsung Spn4235 No video or sound

I am curious as well, as I have the same TV doing the same thing. Caps all look to be good but the BIG caps look to have gotten taller. They aren't bulging but it looks like the outer sleeve has been recessing on the top of the cap and one poly cap is about to come off.

[TechShui]

Re: Samsung Spn4235 No video or sound

Mine_us,
Have you had a chance to check the voltages?

And check the trace leading up to IC30, you'll have to flip the board over to the solder-side to see the trace. On mine there's a scorch, near R34.

The color bands indicate a 2.4k Ohm resistor, but they don't carry that at RadioShack, so I replaced it with a 2.2k and 220 Ohm in series... no change.

There must be something else shorted, the logical step would be for me to replace IC30 next. I think think that's a 12V supply IC, it's hard to read the schematic, it's very blurry, almost as if someone scanned it at a low resolution from the paper version.

Schematic attached, I'm open to suggestions, if anything else looks like it's worth replacing I might as well order it at the same time as the IC.

I'll be getting it from DigiKey.