Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

[cadillacman]

hi guys. Just picked up another craigslist gem. Its a 32" emerson lcd.

Looking at this set, it appears to run the same chassis and plastics as a sony bravia. I will document this set with several pictures so you can confirm or deny my suspicion.

WHen powered on the led goes from red to blue, tv comes up with a picture, then tv immeadiately shuts down, back to red standby led. I have been told its been fussy to power on for awhile now and finally got to the point of not staying powered on now at all.

I suspect bad caps. Getting ready to tear it down now. WIsh me luck.

[Dgtech]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Good luck with that. I hope it's an easy one. Theres nothing like a ten minute fix where it takes you longer to open it up than to fix the problem.

I can't wait till I get my shop done. I'm trying not to get to working on any sets until the shop is done. CHAOS!!!

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

nope, im hosed. for the life of me cannot find this issue.

so far ive found bad solder and reflowed:
bc502, d511, r522, r524, r520, d504, d558, d552, d555, d553, bc552, c511, both coils "C" AND "D", AND all jumpers to inverters. NO CHANGE.

replaced a few caps for giggles (ont he secondary power board) c648, c811, c639 and NO CHANGE.

On the two pin connector between power/inverter baords i have 163vdc at all times.

i did find that half of the inverter board transistors ohm out at 37 ohms between the 1st and 3rd leg, thinking i had a bad xixtor i lifted the right leg on each, the low ohms is not in the transistors, apparently im showing that reading due to something else on the board, this may be normal.


SO at this point i dont know where to go. Caps are jamicon and some other brand, none bulging.

again the set had a red led. Press power green led blinks a few times, picture up then shuts down, goes back into standby untill power is pressed again.

my old lady is going to kill me, moneys tight, i figured this would be an easy one.

[tom66]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

What connector goes from the control/signal board to the power supply board? I'm thinking that the power supply is being shut down by the control board (not the other way around.) One of the pins on that connector will probably be power on/off.

Also, I'm not liking the look of those output diodes (esp. the heat toasted PCB), but they are probably okay.

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

hmm.. there is a 6 or 8 pin connector between the mainboard and the main ps/inverter board i will make a quick note of waht is what then test them all tv off, tv on, and tv back off..

it is marked power on, ground, error 6, error 8, etc so this might get interesting..

this tv is setup weired. wall power goes to the inverter board so the inverter is also partly a power supply, then theres a 2 pin hrness tht goes to the secondary power supply. the only other wires besides ccfls is tht 6-8 pin harness going from the inverter to the main logic pcb(under the metal shield)

[PlainBill]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

The guy who laid this out (I refuse to call him an engineer) certainly came up with some original ideas. I've marked up a few interesting points. A significant effort was made to isolate the inverter power from the audio power. That leaves me to believe the capacitors are pretty darn marginal.

As far as the problem, I see a couple of possibilities. Of course, there are the usual suspects - bad caps, bad solder, bad regulators. I REALLY don't like the signs of overheating on the diodes for the inverter power.

One other possibility - many inverters have a status or error line that goes back the the main board. Those diodes were either seriously underrated, or something in the inverter is drawing too much power. If the inverter shuts down, and alerts the main board, this could explain the sequence of events.

PlainBill

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Ok. none of the inverter diodes check shorted. In the short time the inverter is running, i am getting 24vdc on the banded side of each of those 4 diodes.

CHecking the ribbon cable that runs between the inverter and the mainboard i have:

(pin number) (assignment) (volts off) volts while temporarily on, vshutdown

1: ground 0 - 0 - 0

2: prot. 3 3.3 - 3.3 - 3-3

3: prot. 2 1.4 - 0 - 1.4

4: prot. 1 .4 - 3.2 - slowly back to .4vdc

5: p-on-bl 0 - 3.0 - 0

6: b/l on 0 - 1.2 - 0

7: b/l pwm .464 - .464 - .464

8: ground 0 - 0 - 0


so should i take this is all protections should be 3.3v while powered on???

i tried to follow pin 3 on the inverter side, it seems to stop right at the solder joint of pin 3.

If anybody needs more detailed pics of anything just say so.

chrck this out.. i wonder what they know that we dont...
http://cgi.ebay.com/REPAIR-SERVICE-E...item2a111d2d65

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

for giggles i replaced all the 1000uf caps on the inverter board, replaced a 470uf cap on the inverter board, reflowed a bunch more solder. same.

do you think this is the correct inverter transformer?
( well one of them) http://www.encompassparts.com/products/?FUNLTZ2PC0MS008

also, somebody walk me though how to check my inverter transformers. I want to maks sure im not missing something stupid obious here.

EDIT: GOT IT!!!

one of the inverters is open on the SECONDARY side. The secondaries on these things read like 4 megaohms(between ccfl pins)... I never wouldve thought that. one reads dead open. In a case like this a ring tester would give me a definate answer, but i think we got this.. after pulling the transformer one side of the secondary checks ok the other side checks open.

Now i have to hunt an inverter down, nonew of my parts sets are funai.. oh wait i have a stack of torn down tv boards to go through yet hmmm

haha and after all of that, i find this video...
http://buyviziolcdtv.com/?p=5783



sorry for the edit again and a little search-fu, this looks like what i need.
http://cgi.ebay.com/Funai-TV-CCFL-In...item3cb6615546

[PlainBill]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Good job of troubleshooting the problem. Give yourself one 'Attaboy'.

PlainBill

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

thanks bill.. damn thing. Id figure the primry would have gone not the secondary, but then again i am a newb he he.

what do you guys think of that funai transformer on ebay???


thanks for all your input on my posts guys. THis not only is a rewarding hobby but this is helping me keep food on the table and diapers on my son.

im working hard t my regular job, but its tough right now man. Im sure alot of you guys are in a simular situation. Thank god for badcaps..

and today, i find this post: http://www.riddledtv.com/forums/emer...em8-t1038.html

Oh well, insted of cheating i actually taught myself something on this one i suppose

ONE MORE EBAY TRANSFORMER TO LOOK AT:

http://cgi.ebay.com/Element-TV-Inver...271#vi-content

[PlainBill]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Well, since both auctions are from the same seller and the seller has a 100% feedback rating, and one of the more knowledgeable people on this site uses the same name, I'd say it would be worth buying.

PlainBill

[Village Electronics]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Open transformers are common. Make sure you get the right one.

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

thats my issue. they pretty much all look the same so im having a hard time deciding which one to buy

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Well, since both auctions are from the same seller and the seller has a 100% feedback rating, and one of the more knowledgeable people on this site uses the same name, I'd say it would be worth buying.

PlainBill

interesting... i think i will send him a pm

[PlainBill]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

thats my issue. they pretty much all look the same so im having a hard time deciding which one to buy

Are there any part numbers on the bad transformer?

PlainBill

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

js-hvt-127

the pic i posted earlier is the inverter in question..
let me see if i can attach it again...



aha this listing shows an alternate number as the top number of my dead inverter. I believe this will be the one to go with.
http://cgi.ebay.com/Element-TV-Inver...271#vi-content

[severach]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

The 3PC0XB001 in my Element Electronics 32 LCD HDTV FLX-3220F crossed to the LTZ2PC0MS008. I was worried that the new transformer wouldn't work because the coils between the two parts looked so different. It worked and is still working today so the part cross is correct.

I've never found any documentation that crosses the LTZ2PC0MS008 to the LTZ3PC0XB004 so these probably are not interchangeable.

[testas86]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Hey im having the same issue would you mind giving me a walk through on how to test the transformers and inverters?

[PlainBill]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

Hey im having the same issue would you mind giving me a walk through on how to test the transformers and inverters?

The next to last picture in post #3 shows an inverter transformer. The primary winding is to the top of the picture, the secondary to the bottom. If you look carefully you can see the leads at the bottom corners. Measure the resistance of each secondary. If you look at the last picture, this is the bottom side of the inverter. The arrows point to the secondary pins. If you prefer, you can measure on the bottom of the board. If any reading is different by more than 3%, the transformer is probably bad.

PlainBill

[cadillacman]

Re: Emerson 32" lcd, LC320EM82 S power issues(sony bravia??)

im sure i found mine the wrong way lol, but disconnect all the lamp wires form the inverter. On between the pins of each. should be like 4 megaohms or something like that. If any read open, you likely have an issue with that inverter.

Likewise anothe rmethod would be to plug in one lamp connection at a time, then attempt to power on. If you get one set of lamps tht does not "flash on" when the tv powers on, this is likely the inverter you are having issues with.

DOnt forget to check it over for bad caps, bad solder, test for proper voltages while it is apart.