troubleshooting a tv power supply

Thread Starter

johndoe45

Joined Jan 30, 2010
364
pretty sure needs to be desoldered. can't bend top without desoldering either side. and can't bend the sides without desoldering. why do i need to take off this cover??????
something might be wrong with it???
 

R!f@@

Joined Apr 2, 2009
10,004
The thing is I like to know what I am dealing with. That shield covers the μC, memory and the likes.
If it is too difficult then leave it for now. We'll deal with it if necessary.
Time to show me the complete board as I suggested.
LVDS trouble shooting starts here
 
I,m nt 2 sure if it,s a pwr supp prob in the 1St place.Tv,s come in a wide variety of configuration.2 cut the story short, R u working the Tv off the Rf point or r u trying 2 work it off the plain av terminals.Try the latter 1St. Now tell me if its got a Blu back(This is the equiv of audio mute, supposed2conceal grains n any noise in the absence of a legit signal.) If u do have some screen at all in the 1St place then u r more than 1/2 way thru.now u should decide wether the screen is what is supposed2b a Blu screen or just a plain white raster. Blu screen? then try2 feed an av in pref thru a P.G (Pattern Generator)No improvement? Now connect a cap of abt10Mf or so off the vid in term(Pg av cord well grounded 2 the tv earth/ground...(Hey!BTW I Hope u do know by now the diff bw grd n earth on tv chassis running off smps ...thats another story ) and attach2 a MM +Ve lead n try 2 poke it in2 each ofthe base of the VDO Dr (RGB)(2N2222 Or Eqiv)Transistors.do the same2 the collectors as these r usuall directly coupled 2the Vdo Opt Tr,s(Housed in TO-220 cases mostly)By now u should have some sort of a pic. A weak pic closer 2 the opt & powerful pic at the base of the small sig Tr,s....thats enough h/w 4 now.I hope u get the idea n have something fruitful the nxt time we come online.Tell me the details so that there arn,t 2many "Fill in the Blanks":)-)
 

loosewire

Joined Apr 25, 2008
1,686
Prashanth58,you seem to have great knowledge,
can you post some good pictures describing what
you posted.The pictures we can understand better.
Tell us with pictures how the new curcuit work,please.
Plasma T.V.
 

R!f@@

Joined Apr 2, 2009
10,004
U did not take the way I want. the distance between the board and camera should be same. The board or camera should only move side ways. Read my post. When I put all the pics together I can see the whole board, this way I can trace the things I want and make test points for u. It's easier this way then to post back every time for clearer pics and such
 

Thread Starter

johndoe45

Joined Jan 30, 2010
364
its 16.4 MB
here download link. missing little portion though. i'll put missing portion in this post though. couldn't figure out how to put it in the compilation of pictures

image on left is missing portion image on right is a sample of the full one in download link

full image link like like in thousands by thousands pixels
http://www.megaupload.com/?d=EEPVYZA2
 

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R!f@@

Joined Apr 2, 2009
10,004
The file you are trying to access is temporarily unavailable.

This is what I get, can you use RS.

{Ed}
Did you zip them, if so use the forum to attach it
 

R!f@@

Joined Apr 2, 2009
10,004
OK I got it.
I might need some extra info on the connection details. I will check after a tea break.
It's 5am morning now.
I might update after u sleep.

{ed}
The picture has fuzzy areas, I cannot make the track layout on most areas.
I like to take real good closeups in multiparts . Divide the board to 5 by 5 inch areas and take photos. Put all in one folder Zip it use winrar and up them. donnot combine or compress. I need high res, to do this.
 
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R!f@@

Joined Apr 2, 2009
10,004
U know when I look at the interconnection of the cables of the main board, there are lot of unused male connectors.
I like you to make sure that the connections are correct.
Secondly label a pic of the main board and tell me where the cables goes from the main board. For eg: The Power connector goes to PSU, this I can make out.
PLus the black cable which connects to the LCD. Problem is there are lot of shielded cables used of signal transfer, It might be possible that you have signal connection interchanged. These type of misconnection won't damage anything as there will be no supply connections in them. Just signal, but this will lead no picture and audio problems.
Identify them properly and tell me where and where they connect.
Take ur time and do this right, Please no mistakes in this, if you are wrong, my diagnostics will be wrong and we will get no where.
 

Thread Starter

johndoe45

Joined Jan 30, 2010
364
well the cables only fit in one position. and there is one where it can fit into two but the cable is barely long enough to reach and i don't remember a cable being really tight. will try and do that tonight
 

Thread Starter

johndoe45

Joined Jan 30, 2010
364
here are connections labeled

kind of has legend on right side talking about cables

any questions? just let me know

so white cable is one cable that splits to tv buttons. splits to led. splits to dvd buttons which splits to the dvd drive on other side.

getting tripod set to take pictures. i wish i had bros camera here. hi def like 15 MP. so could probably just take one picture and that would be it :(
last time i just used a box to keep camera at same distance and moved the main board and took pictures
and wasn't as sunny as today so hopefully will come out good today
 

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R!f@@

Joined Apr 2, 2009
10,004
I am concerned abt the sheilded cable which u have colored light blue.
These are signal cables and any mishap here will lead to no picture.
At first the video u showed, I saw menu at a snow picture, I know I saw the menu OSD appear . I donno what it was, but snowy picture tells me the TV is working.
Any way you can come up with a video clip and convert it to mpeg4 and host it in U tube
 

Thread Starter

johndoe45

Joined Jan 30, 2010
364
alright. well you see. i plugged in those light blue cables wrong. and unplugged them as quickly as possible. and smoke came out of dvd drive. :(

but video was up and running still. so maybe the drive finally gave up. i don't know. cause there were only two combinations to put two of those cables. and i picked wrong one first. so i'm guessing one was higher voltage cable and other was lower voltage cable and i plugged high in low?

but the tv did still work after that. taking pictures of board right now. will put everything back together and make a video within 15-20 minutes.

let me show you with a picture
 

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Thread Starter

johndoe45

Joined Jan 30, 2010
364
tring to upload the zip file and get this. tried it three times already. so its going to be megaupload again

http://www.megaupload.com/?d=126ZGQSB



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video isn't going to happen for awhile. i think heat from sun made main unit little too hot. so going to have to wait. no video showing. kind of like when i try to turn on the tv like 8 times. the ground shield gets hot and tv doesn't work

this is hard without you here
 
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R!f@@

Joined Apr 2, 2009
10,004
alright. well you see. i plugged in those light blue cables wrong. and unplugged them as quickly as possible. and smoke came out of dvd drive. :(

but video was up and running still. so maybe the drive finally gave up. i don't know. cause there were only two combinations to put two of those cables. and i picked wrong one first. so i'm guessing one was higher voltage cable and other was lower voltage cable and i plugged high in low?

but the tv did still work after that. taking pictures of board right now. will put everything back together and make a video within 15-20 minutes.

let me show you with a picture
Shud have asked me before inter changing..I was asking you whether u have made a mistake ..not to swap cables..besides you switched a PSU and a signal cable. now that you have showed me a closeup of the cable , I can figure that out
 
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