LE40R88BD Black screen with backlight???

[Easky15]

Hi folks, I have here another 40 inch samsung LE40R88BD which is just displaying a black screen when powered on, I have tested the fuse on the inverter <<<<(t-CON) and i'm getting 13.07DCV on both sides, Is it worth trying the eeprom reset or does this seem like a hardware fault??

[tom66]

Re: LE40R88BD Black screen with backlight???

Check the fuse on the t-con with this fault.

[Easky15]

Re: LE40R88BD Black screen with backlight???

So sorry... I actually ment to write t-con... thats the fuse i tested.......lol

[Easky15]

Re: LE40R88BD Black screen with backlight???

obviously the inverter is fine.. :-)

[Easky15]

Re: LE40R88BD Black screen with backlight???

Anyone any ideas what i should test next or is this a faulty t-con??

[tom66]

Re: LE40R88BD Black screen with backlight???

Picture of t-con please.

[Easky15]

Re: LE40R88BD Black screen with backlight???

here ya go ..

[tom66]

Re: LE40R88BD Black screen with backlight???

On the left hand side of the t-con board, there are points marked AVDD_1, 3.3V, VON, VON_P and VOFF. What voltage do you measure on these? Red probe on test point, black on chassis.

[Easky15]

Re: LE40R88BD Black screen with backlight???

Thanks tom66, Hope this info helps
AVDD_1 = 15.04DCV
3.3V = 3.36DCV
VON = 16.3DCV
VON_P = 20.9DCV
VOFF = 7.51DCV

[tom66]

Re: LE40R88BD Black screen with backlight???

The t-con appears to be working, at least on the power supply front. Try with only one of the LCD panel connectors plugged in (the two ribbon connectors at top.)

It is possible it is main or t-con; have you attempted to get sound with an external source?

[Easky15]

Re: LE40R88BD Black screen with backlight???

Ok done that and with one out i get half a black screen and half white, split vertically right down the middle, Same thing just the other way round when i tried the other connection on it's own.. ;-)

[tom66]

Re: LE40R88BD Black screen with backlight???

Hmm, OK, try with both panel connectors in, and LVDS missing. Full white screen?

[Easky15]

Re: LE40R88BD Black screen with backlight???

Hmm, OK, try with both panel connectors in, and LVDS missing. Full white screen?

Sorry mate i'm still learning.. What's LVDS,

[tom66]

Re: LE40R88BD Black screen with backlight???

The cable between the main and t-con.
LVDS = Low Voltage, Differential Signalling (the type of signal used to transmit video between main and t-con.)

[Easky15]

Re: LE40R88BD Black screen with backlight???

Ok so i think ive removed the one you are talking about, took a pic to be sure, With this out i just get the same black screen with backlight???

[tom66]

Re: LE40R88BD Black screen with backlight???

I don't know what to make of that but I'm not certain if the fault is on the main or t-con. You can try to connect a source to the TV playing audio, just press SOURCE to switch through them and see if you get audio.

[Easky15]

Re: LE40R88BD Black screen with backlight???

Ah ha, Connected HDMI then pressed source button to find it, now the set is switching itself on and off and i hear a clicking relay with the red power led flashing randomly, doesn't appear to be any sort of repeating error code...??

[tom66]

Re: LE40R88BD Black screen with backlight???

That sounds more like a main board fault than anything.

[Dang]

Re: LE40R88BD Black screen with backlight???

Agreed Tom66, been following this thread and I've just recently suffered a very similar issue with the same Tv, only real difference I saw was a pulsing power supply, this manifested it's self with a flickering back light that would cycle faster then slower and so on, a main board change cured it.

[Easky15]

Re: LE40R88BD Black screen with backlight???

Happy days, I'll order a main board then report back the results when i get it fitted, Thanks for all your help tom and dang... ;-)