ACER 8930g no picture

[lefos]

Hello everybody,

Need your help with this one. I received it with problem no picture. Indeed it didn't have picture on the panel but on external monitor it had picture with vertical lines. I changed the chipset of the vga card and now I have backlight, I can see that the lcd is trying to produce picture but with no result. On external monitor I have perfect picture now. I have managed to do a BIOS update from windows so the device is booting normally. Any ideas why it doesn't have picture? On the panel's connector I have all the voltages according to its schematic.
Any help will be great.

[lefos]

Re: ACER 8930g no picture

Forgot to mention that the motherboard has a nec tokin super capacitor but I doubt the problem is from this one.

[dj_ricoh]

Re: ACER 8930g no picture

but when you preheated the board for changing the chip maybe it when tits UP

[lefos]

Re: ACER 8930g no picture

It has a separate small board for the vga that's why I think that the problem is located on the main board.

[atsio]

Re: ACER 8930g no picture

On the panel's connector I have all the voltages according to its schematic.
Any help will be great.

Which voltages do you have?
What is the version of your board?

[lefos]

Re: ACER 8930g no picture

The panel is LTN184HT01-A02 and on its connector I can measure the power voltages from the datasheet.
The board is 6050A2251701-MB-A02

[atsio]

Re: ACER 8930g no picture

Do you have any voltage on the data signals?

[lefos]

Re: ACER 8930g no picture

Do you want on any pin specifically?
Because it is a little pain to open again the panel.
Thanks

[atsio]

Re: ACER 8930g no picture

You can check on pins 12,14,15,17,18,20,21,23,24,26,27,29,30,32,33,35,36 of the LVDS connector on the board

[lefos]

Re: ACER 8930g no picture

Guys thanks a lot for you help. Took some closer look on the vga board and found out that on one transistor's pin the pad was broken. Rebuilt the line and now works like a charm!