Dell E248WFPb lots of vertical lines

[GoneGault]

I have a Dell 24" monitor with vertical lines. Tearing it down, I don't see anything obvious. Can anyone give me some ideas to check?

[selldoor]

Re: Dell E248WFPb lots of vertical lines

Try unplugging cleaning and replugging all cables between video board and
panel.

If you unplug J3 you might get a plain white screen - backlights only.
Any lines showing?

EDIT Unplug with power off

What is that little board between the main and the power

[GoneGault]

Re: Dell E248WFPb lots of vertical lines

Somehow I left a picture of the tcon board off, and I suspect it is the most likely culprit!

[budm]

Re: Dell E248WFPb lots of vertical lines

It does not look like panel problem, either T-CON or the main board. How are the voltages on the T-CON?

[GoneGault]

Re: Dell E248WFPb lots of vertical lines

Voltage across the legs of the main capacitor on the power supply is 164v plugged up, but not turned on. With the monitor turned on it is 303 v. I pulled the main cap and checked it and it's uf value was good. I pulled, tested (they were ok) and replaced the 3 small caps on the main board. Started it up and it still has the vertical lines.
Working upstream, I will now pull and test the caps on the 2 small boards that are between the main board and the tcon.

[GoneGault]

Re: Dell E248WFPb lots of vertical lines

I pulled and checked all the caps on the small board that connects to the main board; all were good. When soldered back in, the same problem persists.
While replacing caps on the main board, I did notice a discoloration around D702 (picture); I don't know if it is significant and I don't know how to check it. Any help would be appreciated.

[Davi.p]

Re: Dell E248WFPb lots of vertical lines

No no no wait... that is not main board, please stop dismounting all the things without a reason, budm, YOU and i suspect the T-con especially and main/scaler board, the little board contains for what i can see 1 or 2 switching dc-dc reg. so if you want to suspect power issue test this board's outputs and report, after test also the T-con testpoints especially GMAVDD2, VGHC1, GAVDD1, GMAVDD1, VGH1, XVCC1, GAV1, GAVCC1, DAVDD1, V33, 5V1, VcomD, after search the web for the keywords -one of previous and the model of the panel- for example "(GAVDD1 OR GMAVDD1) LTM240T1-V2" so you can find places where someone, for example other users, post their voltages, bye!

[nocturnalambition]

Re: Dell E248WFPb lots of vertical lines

thread has been a long time dead but I am having the EXACT same issue as the OP. Any pointers? As I have never attempted a monitor fix.