Weird Custome Built 55" LED Monitor

[Michale32086]

Got a weird one in..

It's a custome built 55" LED Monitor.. Just has DB15 and DVI hookups..

I push the power button and the LED Power Light goes GREEN, then RED after a few seconds.. After a min or so, the Power LED starts blinking red...

There were some loose pads on the TRACE side of the Power PCB. I fixed those and still have the same problem..

All the other components on the Power PCB and the "Main" video board look OK..

Voltages look OK.. I get around 175V steady on the LED connector

At this point, I am leaning towards a bad LED Strip, but I want to exhaust all other possibilities before I break it down that far...

[dick_barton]

Re: Weird Custome Built 55" LED Monitor

It gives the led driver voltage on the board but I can't read it. Have you applied a signal. Some computer monitors turn off if no signal present.

[Andrew F. Ali]

Re: Weird Custome Built 55" LED Monitor

The Backlight LED strips seem to be connected in parallel and what you are seeing is perhaps an open string . Measure WRT GND the -ve pin voltage as you said you have 175V on the +ve pin.

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

It gives the led driver voltage on the board but I can't read it.

These help???

Have you applied a signal. Some computer monitors turn off if no signal present.

ACK!!!! Good point!!!!

Lemme do that..

[R_J]

Re: Weird Custome Built 55" LED Monitor

If you have 175 volts across the led leads going to the panel the led's should light up unless the circuit is open, open led or open connection on a plug etc.

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

OK It does appear the be the backlight issue.. The LED Power light goes green and I can see a latent image on the screen from a laptop...

Andrew, can you simplify the WRT GND -ve thing??? Am a little slow this morning.

[Andrew F. Ali]

Re: Weird Custome Built 55" LED Monitor

WRT GND.....With Respect To Ground....The RED lead on the -ve pin and the BLACK lead to chassis ground.....to check if you have return voltage to the Driver....NP (No Problem)

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

WRT GND.....With Respect To Ground....The RED lead on the -ve pin and the BLACK lead to chassis ground.....to check if you have return voltage to the Driver....NP (No Problem)

0v or, more accurately, .003mV

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

If you have 175 volts across the led leads going to the panel the led's should light up unless the circuit is open, open led or open connection on a plug etc.

Yea, it's beginning to look like I may have to crack this puppy open..

Not looking forward to that...

On the plus side, I don't have to take off the plastic backing or the front bezel.. There is none.

[dick_barton]

Re: Weird Custome Built 55" LED Monitor

Yes it ls looking like a possible led fault. If you measured Vled at 170V and the panel says 108 - 120V then it's probably the open circuit voltage.

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

OK Well, at least I know it's likely the problem.. OK Cracking it open after lunch...

Thanx for all the replies...

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

That did it.. It was a bad LED strip.. Found a replacement that I could wire in and we're all good.

Using those suction handles makes taking off the largest panel a breeze.. I kick myself that I didn't get these sooner...

Thanx to all for all the help...

[dick_barton]

Re: Weird Custome Built 55" LED Monitor

Always nice to have a happy ending.

[Andrew F. Ali]

Re: Weird Custome Built 55" LED Monitor

Good job.

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

Always nice to have a happy ending.

"Indeed"
-Teal'c, STARGATE SG-1

Good job.

Danke..

[SLK001]

Re: Weird Custome Built 55" LED Monitor

That did it.. It was a bad LED strip.. Found a replacement that I could wire in and we're all good.

Using those suction handles makes taking off the largest panel a breeze.. I kick myself that I didn't get these sooner...

Thanx to all for all the help...

Are you referring to the Harbor Freight dual suction cup lifters we discussed earlier?

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

Are you referring to the Harbor Freight dual suction cup lifters we discussed earlier?

I am indeed.. They are a godsend!!! I bought 2 sets, the orange singles and the red duals.. I have used the orange singles exclusively as the panels I have been moving are 50" and lower.. I am wary about the red ones because the suction is pretty intense. But will likely use them on my next 70" +...

[Andrew F. Ali]

Re: Weird Custome Built 55" LED Monitor

A 'must have' tool when doing Panel backlight issues.

[Michale32086]

Re: Weird Custome Built 55" LED Monitor

A 'must have' tool when doing Panel backlight issues.

Yea, when I think back on all the TVs I could have saved had I had these...



Especially that REALLY nice 70" 4K Ultra HD....

Oh well, we go on...

[Andrew F. Ali]

Re: Weird Custome Built 55" LED Monitor

That's for sure!!