Emerson LC320EM2 not powering up

[aasnowskate]

I have an Emerson LC320EM2 that will not power up. No LED or anything.
I purchased a power supply replacement kit that had a resistor, 2 diodes, a mosfet and a transistor.
The problem I found was that Diode D607 was shorted and when I would replace it, it would keep shorting.
the kit I used included:
D607, D610, D604, D640, Q601, Q600, and R608.
After replacing all these parts, I am still having no power, no LED.
Also D607 and D610 are shorted again.
Has anyone seen this before or have any suggestions?
Thanks in advance for any help.

[aasnowskate]

here is a pic of the board and a close up of the power supply part of the board.

[JimmysTGP]

I ran into this train wreck last month. and the only conclusion I made is not the one your looking for, I never found the true problem, so I tossed it. Got to be to much time invested for such a small set. I replaced everything that I could find defective and still no power, same as yours it kept blowing the zeners. Sorry I couldn't be of any help.

[aasnowskate]

Thanks for the reply. I think that is the road I am going to end up taking. I can't find the exact board replacement and everyone I talked to said you have to have the exact board replacement for this power supply.

[kevinm34232]

I successfully did one of these very similar models, it was a Sylvania and the parts I replaced were very close to yours but some more. Check to see if you have a D640 on the bottom of the board, it's an SMD diode and was bad on mine, I beleive causing same issue.

[aasnowskate]

I have replaced the D640 diode. It was in the kit i had ordered. Still not powering up.

[kevinm34232]

Heres a list of what I replaced

Q600 - FET MOS TK10A50D - Mouser
Q601 - TRANSISTOR 2SC2120-Y(TE2 F T) - Ebay
D604 - DIODE ZENER 27BSB-T26 - Part # 568-5893-1-ND
D607 - SWITCHING DIODE 1SS133(T-77) - Part # 1SS133T-77CT-ND
D640 - DIODE SCHOTTKY SMD SK2B-TR - Part # SS210-TP
R602 - CEMENT RESISTOR 5W J 2.2 OHM H 10MM - Part # 280-CR5-2.2-RC
R605 - RES CARBON FILM T 1/4W J 220 OHM - Part # 291-220-RC
R606 - RES CARBON FILM T 1/4W J 180 OHM - Part # 291-180-RC
R608 - METAL OXIDE FILM RES. 2W J 0.18 OHM - Part # PNP300JR-73-0R18
R611 - CEMENT RESISTOR 5W J 2.2 OHM H 10MM - Part # 280-CR5-2.2-RC
F601 - 4A /125V SLO Glass 5x20MM Fuse - Part # F3594-ND

[sansonet]

Originally Posted by kevinm34232

I successfully did one of these very similar models, it was a Sylvania and the parts I replaced were very close to yours but some more. Check to see if you have a D640 on the bottom of the board, it's an SMD diode and was bad on mine, I beleive causing same issue.

I just fixed 32" Emerson TV and it had the same problem. Thanks to this forum and advises here and in another long thread http://www.badcaps.net/forum/showthr...t=25477&page=6
I was able to do it without ordering parts because I already have not working 19" Emerson and found two of those on it's board. One tested with beeps using diode/ continuity tester, the same as one on board from 32", and another one not and had readings that appeared to be correct. So I used it to replace one on 32" board and it came back to life. Now I want try to fix that 19", but I will need two of SK2B since I removed one and another one appears to be bad too. I found them in this listing http://www.ebay.com/itm/5pcs-SK2B-EI...-/171118518069 and another one when I use part number in search SS210 http://www.ebay.com/itm/20pcs-100V-2...-/181155902148

I just not sure if second listing is correct part? It's is cheaper so I prefer buy those if they are the same.

[CapLeaker]

Repaired one of these Emerson TV's today, so saved another one from the junk pile: I used parts I already had on hand and had to cheat a little.
Q600 TK10A50D shorted, replaced with K2698 (had to bend the legs and drill new hole through the heat sink and added isolation mat)
Q601 2SC2120 open, replaced with 2sc5344
D604 27BSB shorted, replaced with 1N4749 1W 24V
D610 1ZB36 shorted, replaced with 1ZB43 43V
D640 SK2B shorted, replaced with FR207
R608 2W 0.18 OHM open, replaced with a 0.18Ohm 5W cement resistor
F601 4A /125V SLO open, replaced with same

Got another working TV!

[Dmaltz]

Originally Posted by kevinm34232

Heres a list of what I replaced

Q600 - FET MOS TK10A50D - Mouser
Q601 - TRANSISTOR 2SC2120-Y(TE2 F T) - Ebay
D604 - DIODE ZENER 27BSB-T26 - Part # 568-5893-1-ND
D607 - SWITCHING DIODE 1SS133(T-77) - Part # 1SS133T-77CT-ND
D640 - DIODE SCHOTTKY SMD SK2B-TR - Part # SS210-TP
R602 - CEMENT RESISTOR 5W J 2.2 OHM H 10MM - Part # 280-CR5-2.2-RC
R605 - RES CARBON FILM T 1/4W J 220 OHM - Part # 291-220-RC
R606 - RES CARBON FILM T 1/4W J 180 OHM - Part # 291-180-RC
R608 - METAL OXIDE FILM RES. 2W J 0.18 OHM - Part # PNP300JR-73-0R18
R611 - CEMENT RESISTOR 5W J 2.2 OHM H 10MM - Part # 280-CR5-2.2-RC
F601 - 4A /125V SLO Glass 5x20MM Fuse - Part # F3594-ND

On my model R605 & R606 were both 120 ohms.
Since D640 appears to be the cause of all the other components going bad I decided to use a schottky diode with greater current capacity to avoid another failure. Digikey had one that handles 5 amps rather than 2. Their part number is SB5100DICT-ND.
This is a through hole diode so I carefully drilled a couple holes through the circuit board and installed it from the top. So far so good.

[art_dodger]

I just repaired one of these as well. What a bloody nightmare!

Initially purchased the typical repair kit, replaced 12 components, promptly re-blew Q600, Q601, D604 & D610. Problem child turned out to be D640. (It wasn't initially obvious because everything else was on the cold side.) I finally ended up pulling T600 from the board just to circuit-trace and tracked down a shorted D640. Re-replaced blown stuff, *poof*, I was finally able to call my customer for pickup of a working TV.

A little trick when trouble-shooting this board - I lifted a leg on R605 to isolate and traced with voltage measurements. Surprisingly, the schematic for this set is quite good, with reference voltages, etc.

No real new info here for anyone I guess... I was just so excited about finally getting this set out of my shop, I had to tell someone! :-)

[CapLeaker]

On these TV sets, D640 is what causes the problem. So I hope you did upgrade D640 with something beefier. I had the FR207 originally in there, but I did take it out again and used a 4A 200V diode instead. This TV that I repaired is still running to date.

[culcuhain]

Got another one of these this week. Ordered the shopjimmy kit. D640 is the culprit. Both sets. Easy fix.

[Carlos tce]

Originally Posted by Dmaltz

On my model R605 & R606 were both 120 ohms.
Since D640 appears to be the cause of all the other components going bad I decided to use a schottky diode with greater current capacity to avoid another failure. Digikey had one that handles 5 amps rather than 2. Their part number is SB5100DICT-ND.
This is a through hole diode so I carefully drilled a couple holes through the circuit board and installed it from the top. So far so good.

friend Could you help me I have the same card the same problem that no electrical current comes out and I would like to know who can help me to detect the voltage output how much voltage should I reach the regulator and from the regulator to the cold card because I do not know how much voltage must handle or must reach the regulator so that this regulator feeds the cold card I need help because I already rectify everything that would be my friend's list here below and replace all the parts but not yet I do not have cold current in The cold card I do not have power and this I would like to know who can help me with this detail because this time I am going to send you a photograph so that you can see How it is In what state is my card and the specific area where I would like to know if someone Can you help me with a diagram or something to identify the electric current lines, what would be the value of each line? Thanks

[CapLeaker]

Here is the service manual. BTW the TV i repaired is still going!