Samsung LN46A550 Power Cycling

[Agent24]

Re: Samsung LN46A550 Power Cycling

Do you mean what they are as in two resitors and one capacitor or do you need the values the resistor has it wrote on it not sure what value the capacitors are though maybe in the schematic though.

??? It's two capacitors one resistor...

R106 at least is clearly a 2.7k, probably 0805 size. No idea what value C107 and C139 are.

[vinceroger69]

Re: Samsung LN46A550 Power Cycling

??? It's two capacitors one resistor...

R106 at least is clearly a 2.7k, probably 0805 size. No idea what value C107 and C139 are.

sorry i was too late to edit (just re read that now what i wrote) im sure/hope the op got what i meant when i said the resitor had the marking on it.

[buckscrape]

Re: Samsung LN46A550 Power Cycling

Thanks for the info on R106, did find out C107 & C139 are 10nf 50v.

Thanks again

[vinceroger69]

Re: Samsung LN46A550 Power Cycling

Thanks for the info on R106, did find out C107 & C139 are 10nf 50v.

Thanks again

Thanks for the update on the values may help someone else in the future.

[Louis82]

Re: Samsung LN46A550 Power Cycling

Hello guys,

I have same tv, same issue (cycling). Replaced what Budm has suggested C102 and C131. I used KMG 100uf 16v, I also replace MP2363DN and I still continue having same issue. Clicks and clicks, it comes on eventually and goes right off after 8 seconds. Any other suggestion? Thanks

[Louis82]

Re: Samsung LN46A550 Power Cycling

Purchased new tantalum caps from digikey, soldered them on main board and still same. Tv clicks. Hey Budm, any suggestions?
Thank you!

[budm]

Re: Samsung LN46A550 Power Cycling

Check the standby DCV to see if it is going up and down.

[Louis82]

Re: Samsung LN46A550 Power Cycling

STB on main board i get steady 5.1v

[Louis82]

Re: Samsung LN46A550 Power Cycling

Any other suggestion??

[Louis82]

Re: Samsung LN46A550 Power Cycling

Here is a picture in case anybody needs one.

[budm]

Re: Samsung LN46A550 Power Cycling

Is the Voltage across C102 steady? I never run into problem where C102 replacement does not fix the recycling problem.

[Louis82]

Re: Samsung LN46A550 Power Cycling

I know it's very strange. One just worked. I still have 2 more that are driving me crazy. change c102 twice already. Yes voltage is steady. Starting to think that maybe is the EEPROM. Any experience with defective eeproms on this board?

[budm]

Re: Samsung LN46A550 Power Cycling

I know it's very strange. One just worked. I still have 2 more that are driving me crazy. change c102 twice already. Yes voltage is steady. Starting to think that maybe is the EEPROM. Any experience with defective eeproms on this board?

Sorry, no.

[Agent24]

Re: Samsung LN46A550 Power Cycling

Well you could always try copying the EEPROM from the working one?

[Louis82]

Re: Samsung LN46A550 Power Cycling

Is the EEPROM the big IC (many pins) located in the bottom of the board?

[Agent24]

Re: Samsung LN46A550 Power Cycling

Very unlikely for something built this recently. Most things now use serial-access EEPROMs, so they typically only have 8 pins. Older parallel ones used 28-32 pins or so.
The IC with many pins you speak of is probably the main CPU\GPU or other such processor\ASIC.

So you're looking for an IC with 8 pins that has a part number most likely 24C..., 25C..., 93C... or something similar.

[Louis82]

Re: Samsung LN46A550 Power Cycling

I do have experience replacing eeproms. I have looked for the 8 pin ic but can't identify which one is. Here is a pic of board.

[Agent24]

Re: Samsung LN46A550 Power Cycling

Can you post up all the part numbers for all the 8-pin chips? I can't read any of them in that picture. Are there any on the other side?

If it's none of those, it may be under the RF shield next to the processor, or might even be embedded into the CPU.

[Louis82]

Re: Samsung LN46A550 Power Cycling

ATMLH844
AP358
BOTTOM:
ATMLH834 (QTY: 3)
4435B

On the top of the board I see a IC that after checking specs it says that is a flash memory. Not sure if that might be the eeprom. Part number is WT61P6S

Thank you

[Agent24]

Re: Samsung LN46A550 Power Cycling

WT61P6S is another microcontroller. It probably has an internal flash memory, rather than being one.

AP358 is an opamp, 4435B a MOSFET.

ATMLH844 and ATMLH834 are likely to be EEPROMs, but you need to write the other text on the chip, not just the first line. That first line is just part of Atmel's datecode, the 2nd (and maybe 3rd) lines tell the actual part number (in cryptic SMD code)