samsung LN-T3253H no picture red standby light

[budm]

Re: samsung LN-T3253H no picture red standby light

Nope.

[hapollo]

Re: samsung LN-T3253H no picture red standby light

Yes, its the value of the component as printed on the body.
I.E. resistor RM801 in the SCH is 0.22 Ohm 1W Fusible resistor (FR)
CY803 is the safety cap (x/y type) 0.001uf 400V X/Y safety cap.
CM810 is 2.2nF (0.0022uF) 1KV Ceramic cap
CM801 is 0.0033uF 100V, is this damaged by the glue?
CM802 is 0.47uF 25V, is this damaged by the glue?
PC803 Opto couple NEC P/N PS2561

Can you please post the pictures of these parts?

Is the RM801 .22 ohm 1w FR one of these? Does it tolerance matter in this application? 1%, 2%, 5% ?

http://www.mouser.com/Passive-Compon...z0wpn9Z1z0x6fr

[budm]

Re: samsung LN-T3253H no picture red standby light

That is the MOX not fusible:
Fusible resistor:
http://www.digikey.com/product-searc...=0&pageSize=25

[hapollo]

Re: samsung LN-T3253H no picture red standby light

That is the MOX not fusible:
Fusible resistor:
http://www.digikey.com/product-searc...=0&pageSize=25

Thanks. The links shows 1/3W or 1/2W. The original rating was 1w. Does it matter is this case?

[budm]

Re: samsung LN-T3253H no picture red standby light

You may be able to get away with 1/2 W, otherwise you may have to get it from EBAY.

[dsc]

Re: samsung LN-T3253H no picture red standby light

Glad I came across this thread, had one bad cap but still refused to power on.
Cleaned the glue and discovered the RM801 had also popped.
Got a replacement from NTE as they were about the only place in MA that carries much of anything anymore.
Thank you!

[miracj]

Re: samsung LN-T3253H no picture red standby light

New to the forum.

I have the Samsung Model LN-T3253H manufactured December 2007.

All of the electrolytic caps looked good (no visible leakage, or swollen tops), but with over 8 years on them, I replaced them all as a quick 1st level fix before finding this thread.

There was burned glue under the in rush current limiter DSC 5D-15 (NT811S) and the top pads looked a little corroded (greenish). In circuit value measures 7.6 ohms. I suspect that is OK, but am not positive.

The 2.2nF 1KV Ceramic cap (CM810) had burned glue over it, which I removed. The cap itself shows no issue visually. The top side of the board looks blackened around its holes on the top of the board. The cap does not read shorted, but obviously can still be bad. No ESR to really check it, but cheap enough to replace. This is where the smell of burned electronics is the strongest.

The 0.22 ohm 1w Fusible Resistor (RM801) was measured to be open, so that is definitely bad. Not sure where to pick up a 1 watt version, or if I could substitute two 1/2 watt 0.47 ohm versions in parallel. Any thoughts?

.001uF 400V (CY803S) ceramic cap had some burned glue on it, looks good visually. Probably will get replacement anyway.

Finally I don't know if the MOSFETs FQPF9N50C (QM801 & QM802) are bad. They don't look as if they have over heated or failed, but for an extra $3, I'll probably order them just in case.

Thanks for any thoughts and inputs.

P.S. I taught my son to solder with this repair, so a win even if we don't get it to work.

[dick_barton]

Re: samsung LN-T3253H no picture red standby light

Digikey should be able to provide the parts you need.

Mosfet testing
https://www.youtube.com/watch?v=gloikp9t2dA

[miracj]

Re: samsung LN-T3253H no picture red standby light

Digikey should be able to provide the parts you need.

Thank you. That's where I normally order for small quantities. But while Digi-Key have many parts, the 0.22 ohm 1 Watt Fusible Resistor they do not carry in normal stock for small quantities, and I don't see other sources for that value.

Again, my thought is to substitute two 1/2 watt 0.47 ohm versions in parallel, but I'm not sure of the safety implications if just one of them blows. Alternatively, If I put two 0.1 ohm 1/2 watt, or two 0.12 ohm 1/2 watt fusible resistors (which Digi-Key does have) in series, I believe I am good, as the moment one blows, the circuit is broken. Thoughts?

Mosfet testing
https://www.youtube.com/watch?v=gloikp9t2dA

I already knew that, but that's a nice video that I'll pass to my son.

[miracj]

Re: samsung LN-T3253H no picture red standby light

I still don't know for sure what will be better to replace the 0.22 ohm 1 Watt Fusible Resistor. Digikey has in stock 0.1 ohm, 2 watt and 0.47 ohm 1/2 watt values, and that's about it.

But I don't want to risk safety. I believe the two 0.1 ohm in series is the best option (rather than two 0.47 ohm in parallel). Unless, the value is not that critical, in which case, I can probably go with a single 0.1 ohm.

Thanks in advance for any opinions!

[budm]

Re: samsung LN-T3253H no picture red standby light

You can use 0.22 Ohm 1W MOX type which is Flame proof so it will not catch on fire.
http://www.digikey.com/product-detai...0TR-ND/2021716

[miracj]

Re: samsung LN-T3253H no picture red standby light

You can use 0.22 Ohm 1W MOX type which is Flame proof so it will not catch on fire.
http://www.digikey.com/product-detai...0TR-ND/2021716

Thanks so much for the help!

[miracj]

Re: samsung LN-T3253H no picture red standby light

I ended up finishing up the repair successfully. MOSFETs checked out OK.

Removed all burned glue, replaced the 0.22 Ohm 1W Fusible resistor (RM801) and the 2.2nF 1KV Ceramic cap (CM810), and system powered up just fine.

Thanks to all

[budm]

Re: samsung LN-T3253H no picture red standby light

Thanks for the follow-up.

[darthyoda]

Re: samsung LN-T3253H no picture red standby light

First off, thanks to the folks in this forum. My beautiful Samsung LNT3253H, after 9 years of excellent service, just burned out too (without notice - no warning signs - I just turned it on, heard a loud pop, and that was it). Standby light still comes on, and TV tries to turn on (standby light goes off, and blue accent light very dimly lights for a couple of seconds, and then the standby light comes back on, and the process repeats ad nauseam). I used this forum as the basis for my troubleshooting. So, I popped the top, and my power supply board looked just like jose6326's. Some black/green between RM801 FR, and CM810 ceramic capacitor. I also have what looks like corrosion between the NT811S ICL and the glue/peg that was attached to it. I just order parts vis-a-vis budm's suggestion...

http://www.digikey.ca/product-detail...0TR-ND/2021716
http://www.digikey.ca/product-search...5-R3AD222KANRA

...I also ordered the following to replace NT811S, though I'm not sure it's the right part (I'm a complete newbie to this whole thing...my TV burning out turned me to Google)...
http://www.digikey.ca/product-detail...210-ND/1190985
...can anybody confirm this for me?

Where is this SCH you keep referring to, budm? I can't find a proper electronic parts list for this TV.

Also, I don't have a meter to read values. I am, however, going to borrow one, along with a soldering iron, and wick, and try my virgin attempt at soldering, and reading ohms, etc values. I feel so manly.

[darthyoda]

Re: samsung LN-T3253H no picture red standby light

Hrmm, I don't see an edit button here, so, sorry about the new post. Now that I am a member, I see attachments. I see your Samsung_BN44-00155A_[SCH].pdf attachment now, budm; I assume this is the document to which you were referring. It shows it as a thermistor 5D15. No other values specified...like I don't know if amperage, etc, is important. I don't even know what the "15" stand for. The 5 is, presumably, ohms. Thanks.

[budm]

Re: samsung LN-T3253H no picture red standby light

5 Ohms @25c, 15 = 15mm dia.

[darthyoda]

Re: samsung LN-T3253H no picture red standby light

Did I order the correct replacement part?

[darthyoda]

Re: samsung LN-T3253H no picture red standby light

So, using a multimeter, the original NT811S ICL measures 5.9 ohms when connected to board. From my readings here, that's good. I don't know if you can measure the ceramic cap in CM810 via any setting? The onboard RM801 FR measures 1 no matter which ohm setting I put it on - I assume that means it's fried?

[darthyoda]

Re: samsung LN-T3253H no picture red standby light

Update...

Removed RM801 resistor, as it was clearly torched, and measured open. Cleaned off browned glue with isopropyl and tools from manicure set (yup). Popped in new resistor. Life. This resistor is in there now, as per budm's suggestion in this thread...

http://www.digikey.ca/product-detail...0TR-ND/2021716

The CM810 ceramic capacitor seems to be ok. The replacement suggested in this forum might just be too big for that slot, though I didn't make any attempt to replace it. It is certainly bigger than what's there now, and the leads look to be too wide to fit. Others here who replaced there's may just correct me, however.

With my extremely limited knowledge (in that this is the first time I've ever done anything like this), here's what I think happened...

There was a scorch mark indented on the component side of the board going from 1 lead of the RM801 resistor to 1 lead on the CM810 ceramic capacitor. Looks like the browned glue created a short between the two components, and fused the RM801 resistor.

TV has been up for an hour, and counting. Here's hoping my limited skills created a permanent fix. Thanks to the others in this thread leading the way.