Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

[martyparish]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

Alright Budm, I will try to trace it back. Not sure if this is more than 2 layer board but it's hard to see where the traces are going.

I'll get the panel spec and # up asap. The panel id sticker is under a piece of strut..

Again I appreciate it!!!

[martyparish]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

The service manual has the diagram for the main board?

Sorry, yes there are schematics but they are really broken up into bits. I'll attach the schematics here.

[stj]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

did you try it with the video cable from the main to the t-con unplugged?
i would incase there is a short on the t-con pulling it down.

[tom66]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

Alright Budm, I will try to trace it back. Not sure if this is more than 2 layer board but it's hard to see where the traces are going.

I'll get the panel spec and # up asap. The panel id sticker is under a piece of strut..

Again I appreciate it!!!

It'll be 6 or 8 layers, almost always...the density of these designs, even on the basic sets, is surprising.

[martyparish]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

I'm back at it! I love this stuff lol.

BTW, we can look up the LCD panel spec to see if the T-CON is running on 5V or 12V just to be sure

V315B1-L01

It appears to be 5V but not 100% sure. CHI MEI pdf attached.
2.2.1 TFT LCD MODULE
Value Item Symbol Min. Max. Unit Note
Power Supply Voltage Vcc -0.3 6.0 V
Input Signal Voltage VIN -0.3 3.6 V (1)

did you try it with the video cable from the main to the t-con unplugged?
i would incase there is a short on the t-con pulling it down.

Thanks stj. I tried that and no change at all.

It'll be 6 or 8 layers, almost always...

lol! Yeah that's a bit more than 2!

[martyparish]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

You can trace out the Source pin, it should lead back to the either 12V or the 13V terminal of the power connector.

Okay traced source back to 5.3V pin on connector.

If you use 1K resistor between GATE and Ground then you should be able to force on that MOSFET.

I connected resistor and the drain voltage came up to 5v.

Still same symptoms unfortunately. I'm going to keep looking at the schematic to see if I can find anything else to look for.

[martyparish]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

Interesting development...

Removed the temporary Gate to ground resistor. PANEL_VCC goes back to 0v.

However, if I unplug the connector to the inverter, PANEL_VCC rises to 5.4v.

Soooo... could this be an inverter issue???

[stj]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

maybe.
does it all work without it?

[martyparish]

Re: Possible sabotage?! Samsung 32" LNT3242HX/XAA LNT3242H

ahh man... looks like it was another bonehead move on my part. I think the friggin temp resistor lead was accidentally grounded when I measured the 5.4v... (I have the resistor soldered on the end of a short lead since the mosfet in on the bottom)

So back to "no panel_vcc" and not working when I force the mosfet on either.