element eldft551 not turning on

[cashkennedy]

Re: element eldft551 not turning on

I should get this digital scope

http://www.amazon.com/AGPtek-DSO-Nan...l+oscilloscope

then yall will really hate me unfortunately I wouldn't know enough about using a scope to work through the lack of documentation on that one

[tom66]

Re: element eldft551 not turning on

That scope is basically useless, waste of money. Don't bother.

Something like this is worthwhile investment.
http://www.amazon.com/Rigol-DS1052E-...ywords=ds1052e

I have the 100MHz version but there's no difference if you just repair TVs.

Of course a good, old HP, Tek, LeCroy will also suit you well, and can be had for less than the Rigol. I owned an HP 54501A for a time, and it worked quite well, only main complaint, it was very sluggish to use due to the 16MHz processor.

[budm]

Re: element eldft551 not turning on

By the way, I look at the diagram again, it looks like soem one has reverse engineered the board and draw the diagram, there is no company name, SCH revision, etc. but it seems to be close enough for troubleshooting.

[tom66]

Re: element eldft551 not turning on

I don't know in particular where the schematics came from, I just got a disk of them . Some are clearly engineering diagrams, others not so sure.

[budm]

Re: element eldft551 not turning on

So @CHKDY, where are you at this point?

[cashkennedy]

Re: element eldft551 not turning on

Power supply appears to work fine now.

Tcon lvds connector and lvds cable burnt beyond repairability.

Ordered tcon + lvds package on ebay for 33 after shipping.

100 dollars for broken set + 33 for parts. Hopefully = ~300 in profit.

Bought a 42" that has inverters or bulb problems (seller said his house had a power surge and insurance covered all his items)

Buying a 50" samsung plasma that was part of the badcaps class action lawsuit. wont start up. paying $125... i think im paying to much, but im not tight on cash so ill figure out if im loosing money (not making enough to make my time worth it) once i run into 1 that i cant fix.

[cashkennedy]

Re: element eldft551 not turning on

I am still slight worried that it seems unlikely for saran wrap to have shorted the lvds, since it would have been just barely in contact with it, saran wrap does have static cling though ... (saran wrap is a brand name, it england they probably call it like nicker waxing or something retarded, or misspronounce cellophane as chellofan)

If you have any sugestions for how to test the lvds output of the mainboard for "safety" please tell me.

I did some basic voltage readings on all the conectors and the 12v wires were 12, and the lvds wires all ranged between .5-2v. Im not sure if current could be an issue on these, since the wires are tiny.

[tom66]

Re: element eldft551 not turning on

Uh, we call it cling film here. Let me remind you Sir, that we invented English, you just modified it into the bastard child* known as American English.

*not that I don't appreciate some parts of American English. Like color makes much more sense than colour. And the storage compartment of a car does look more like a trunk, than a boot. And, indeed, you are more likely to know a sidewalk from a pavement. But your misuse (ney, abuse) of "hold down the fort" takes the biscuit.

[budm]

Re: element eldft551 not turning on

I hope that the switched MOSFET that supplies the B+ to the T-CON board did not get damaged when the cables burnt up, you will have to trace out the B+ trace at the connector to the T-CON back to the switched MOSFET. The MOSFET is turn on when the TV is turn on, so the cuurent will flow through the MOSFET to the T-CON fuse.

[cashkennedy]

Re: element eldft551 not turning on

I have never heard of the term B+, what does that refer to? Is the 12v that is provided to the board provided by B+?

Other then the blue / white twisted pairs there are 3 red wires on the main board side. These carry 12v power. There is also a few black wires scattered through out that appear to be grounds. The red wires line up to the fuse which still tests good on the tcon.

The ground wires are really at the heart of what burnt on the connector from what I can tell?

There are also 4 control wires that turn tcon on / affect contrast I suppose those are all no where near where the lvds burnt up. The whole wiring harness has a large screwed case ground on 1 end, but I assume that's just connected on 1 end as a shield, and does not actualy connect to the tcon through the conector?

[cashkennedy]

Re: element eldft551 not turning on

I replaced the tcon and lvds cable and set works fine now.

Whether the connector fried from the cellophane or because I didn't have the tcon properly grounded we will never know.

So to recap > power supply turns off voltages after 2 seconds can be possibly fixed by removing failed transistor in the error sensing circuits, and make sure you don't put cellophane near circuits , and don't test tcons without them being grounded well?