30" Dell Ultrasharp U3011T troubles

[ktzz]

Re: 30" Dell Ultrasharp U3011T troubles

i got two dell u3011. power problem!

[eriksalo]

Re: 30" Dell Ultrasharp U3011T troubles

I've decided to officially give up on this one and let someone else try.

Have a look at my new project, a Dell 30" 3007. It won't go into high resolution (and it's not the cables).

https://www.badcaps.net/forum/showthread.php?t=35515

Thanks for all your help.

[eriksalo]

Re: 30" Dell Ultrasharp U3011T troubles

I removed the bezel from the monitor so I could access the tab bonds.

For all the world, the tab bonds seem FINE. Visual inspection shows nothing. I can't change the picture by gently touching the tabs. Is this common?

Flex cables from tab bonds board to T-Con looks fine. I will mic out the LVDS connections next. As reminder, I tried new T-Con and main boards.

I've posted a second video showing the screen while I'm manipulating the tab bonds.

A real mystery! Video is here:

http://youtu.be/KyRYQwcVdvI

[Topcat]

Re: 30" Dell Ultrasharp U3011T troubles

I got a T-CON board and a main board from payless components.

So Sad! Symptoms are the same after replacing both boards.

Any ideas where to go next? I plan to take apart the panel casing and have a look but.....

Darn....the panel is gone....and thats what I needed!!

Ohh well, looks like you're in the same boat as me.....a boat with a really cool anchor!!

[Lumberjack777]

Re: 30" Dell Ultrasharp U3011T troubles

I think a likely candidate is the >>> LVDS cable <<<<. Or the T-Con ribbons.
I always include those when I sell a main board or T-Con board on eBay.
I won't need them, but the buyer just might.

[Davi.p]

Re: 30" Dell Ultrasharp U3011T troubles

i dont think is a fpc problem, erik in post 8 has already tried pushing those.. it can be at least 2 chips on the screen's board, and discrete components, those could be tested/changed.

[selldoor]

Re: 30" Dell Ultrasharp U3011T troubles

read up up fixing tab bonds we already gave a few links. Main thing is to be careful and not do more damage getting panel from frame. At least looking at this will not involve further outlay.

[eriksalo]

Re: 30" Dell Ultrasharp U3011T troubles

I got a T-CON board and a main board from payless components.

So Sad! Symptoms are the same after replacing both boards.

Any ideas where to go next? I plan to take apart the panel casing and have a look but.....

[Topcat]

Re: 30" Dell Ultrasharp troubles

I will post results later this week, thanks again for all the replies.

Erik

I too have been keeping a close eye on this thread. I hope you get 'er goin!

[eriksalo]

Re: 30" Dell Ultrasharp troubles

Given all the great responses, I am going to order a new T-CON board.

It seems there's a good chance this monitor is repairable and I haven't been able to find anything obviously wrong with the T-CON so I will hope the main chip is fried and that a new one will fix it. $50 is a small price to pay to try and fix such an expensive monitor.

I will post results later this week, thanks again for all the replies.

Erik

[eriksalo]

Re: 30" Dell Ultrasharp troubles

The point to test are VLCD, VDD, VCC, 1,8V, i don't have the right value but you can search the web for for example: "LM300WQ5 (VLCD OR VDD OR VCC OR 1,8V)" you can find other user that have posted their values and so compare..

Thanks for the idea. VLCD was the only parameter I was able to find a spec for and it's in range. Here are the results:

VLCD: Measured 17.83V, Spec 18.0 +/-1 (In Range)
VDD: Measured 15.44 VDC
VCC: Measured 3.32 VDC (this seems right)
VGH: Measured 23.89
VGL: Measured -7.45 (last time was -10.5)

[Davi.p]

Re: 30" Dell Ultrasharp troubles

The point to test are VLCD, VDD, VCC, 1,8V, i don't have the right value but you can search the web for for example: "LM300WQ5 (VLCD OR VDD OR VCC OR 1,8V)" you can find other user that have posted their values and so compare..

[eriksalo]

Re: 30" Dell Ultrasharp troubles

I may be missing something here (often do) but I see you have marked VGH but VGL
seems to be elsewhere (from VGH up and across U2)

Right you are... A mistake of photo editing, not of measurement . I re-marked with the correct VGL. That is where I measured. If you zoom in, you can see the little mark made by my scope probe when I traced it. New pic attached.

[selldoor]

Re: 30" Dell Ultrasharp troubles

I may be missing something here (often do) but I see you have marked VGH but VGL
seems to be elsewhere (from VGH up and across U2)

[eriksalo]

Re: 30" Dell Ultrasharp troubles

Post at least an hires image of tcon, we can find those points to test others voltages, i cannot find it in the web, you can buy it at:
http://www.lcd-chip.com/ViewDetails12873.aspx

Here are pictures of the T-CON. I think you can read all the labels. I've circled in yellow (first pic, lower left) where I measured VGH and VGL.

Thanks again for all the help!

[Davi.p]

Re: 30" Dell Ultrasharp troubles

Post at least an hires image of tcon, we can find those points to test others voltages, i cannot find it in the web, you can buy it at:
http://www.lcd-chip.com/ViewDetails12873.aspx

[eriksalo]

Re: 30" Dell Ultrasharp troubles

Try to locate positive and negative gate drive voltages. On T-con board. They are usually labelled VGH and VGL. Typically +25V and -10V respectively. Low VGL could cause this. I had an LCD TV with unstable image and horizontal lines - the VGL voltage was measuring 0V.

This is a great idea. I measured VGH and VGL on the T-Con board. Sadly, the voltages looked good and were solid as a rock on the scope:

VGH: +23.89 VDC
VGL: -10.5 VDC

Think I should try a new T-Con anyway?

[Lumberjack777]

Re: 30" Dell Ultrasharp troubles

Try to locate positive and negative gate drive voltages. On T-con board. They are usually labelled VGH and VGL. Typically +25V and -10V respectively. Low VGL could cause this. I had an LCD TV with unstable image and horizontal lines - the VGL voltage was measuring 0V.

That's interesting. I'm going to file that in my personal memory bank

That video really helped a lot Erik! Your voltages on your main board looked correct. I'm starting to think this might be T-con also. The blockiness; the lines. Hopefully you can track down the abnormal voltages and fix it. Your T-con board is also readily available for about 52 bucks all over and eBay.

Sorry The Boss! I think this looks repairable. Hopefully you can get a deal on eBay too <-- 3 Stooges icon

[Davi.p]

Re: 30" Dell Ultrasharp troubles

This is an example from another TCON, if VGL is bad check those component
around D105 diode. Bye.

[tom66]

Re: 30" Dell Ultrasharp troubles

Try to locate positive and negative gate drive voltages. On T-con board. They are usually labelled VGH and VGL. Typically +25V and -10V respectively. Low VGL could cause this. I had an LCD TV with unstable image and horizontal lines - the VGL voltage was measuring 0V.