messed up LVDS on a acer 5920

[Learn2Day]

Hi guys,

I messed up LVDS connection on this laptop, hope you can help me out..

It all happened when i was replacing the LVDS cable, and the replacement was shorted without my knowledge.. a spark came out, and when i replaced back the old cable it wasn't working anymore.. I have neither image or backlight.

I thought it might be a broken fuse like in other laptops, but i've searched around and didn't find any fuse.. Do you guys know what i should check?

Thanks.

[selldoor]

Re: messed up LVDS on a acer 5920

perhaps pictures of the area around the connector would help and of
the inverter board in the screen and perhaps the board if there is one on the
back of the panel.
Have you tried with an external monitor?
If the cable is damaged and in place there doesnt seem much point in trying to fix the laptop as it will just blow again. Have you tried continuity testing each wire in the cable and also for shorts between the pins.

[Learn2Day]

Re: messed up LVDS on a acer 5920

Yeah, forgot to mention, VGA output is working fine.

Not sure how pics would help, but the schematics might..

http://www.electronica-pt.com/index....down/id,18113/

[Learn2Day]

Re: messed up LVDS on a acer 5920

Here's some pics.

Thanks.

[selldoor]

Re: messed up LVDS on a acer 5920

I am not good on schematics but better at pictures. I was looking for components that might blow like a fuse.
Perhaps test the zero rated resistors for continuity - ones with 000 on.

[Learn2Day]

Re: messed up LVDS on a acer 5920

These resistors have continuity. I also checked connector for 3 and 5V, and it's present.

Thanks.

[selldoor]

Re: messed up LVDS on a acer 5920

OK after checking the cable for shorts and breaks think you need to get into the inverter board then - may be a fuse on it?

[khaahk]

Re: messed up LVDS on a acer 5920

Did you leave the battery connected while changing the cable?
VIN voltage on R9 present?
LCDVCC on pins 3&5 present?

[Learn2Day]

Re: messed up LVDS on a acer 5920

It's not the inverter cuz i was using a different inverter/screen/cable when it happened..
18V in R9, and 3V present in pins 3&5.

Thanks.

[selldoor]

Re: messed up LVDS on a acer 5920

Sorry I dont follow this.

1- you had a laptop which didnt output to the laptop screen ?
2- you decided to try a different lvds cable
3- cable was faulty.

So why would it work with the old cable.inverter.panel when it didnt work before?

I think we are going to need a more detailed step by step of what you were doing and why.

[Learn2Day]

Re: messed up LVDS on a acer 5920

Let me explain you a little better..
The laptop screen was working fine but had a couple of green lines on the right side, in a stupid (very stupid) quick move to rule out board i jumped the gun and inserted spare replacements (screen, inverter and cable), when i did this charger power went down, and up again when i touched the LVDS connector. thinking it was a bad contact i touched it again, it sparked and got busted.

Hope this helps.

[selldoor]

Re: messed up LVDS on a acer 5920

Let me explain you a little better..
The laptop screen was working fine but had a couple of green lines on the right side, in a stupid (very stupid) quick move to rule out board i jumped the gun and inserted spare replacements (screen, inverter and cable), when i did this charger power went down, and up again when i touched the LVDS connector. thinking it was a bad contact i touched it again, it sparked and got busted.

Hope this helps.

OK when you unplugged the old panel and lvds from the mainboard the
laptop was up and running?.

In which case is it possible that when you unplugged the old screen a surge
blew a fuse on the inverter board. That might explain why when you plug it in now it doesnt work.

Any further plugging/unplugging should be done with the power off and the
main battery removed.

If you are sure the new screen is the same or at least compatible then
again if you plugged it in when the laptop was powered up it could have caused a surge which blew fuses on its inverter board and caused the
charger to cut out.

Also just to be sure I am assuming its not possible to connect the lvds
upside down.?

[tomodachi]

Re: messed up LVDS on a acer 5920

if you fail at all methods, prepare to replace the KBC chip

[Learn2Day]

Re: messed up LVDS on a acer 5920

Hi,

It's not the inverter. If it was the inverter i would have image and no backlight.

tomodachi, what's tha KBC chip?

[tomodachi]

Re: messed up LVDS on a acer 5920

Hi,

It's not the inverter. If it was the inverter i would have image and no backlight.

tomodachi, what's tha KBC chip?

[/IMG]

[Learn2Day]

Re: messed up LVDS on a acer 5920

Wouldn't that chip affect VGA output as well?

Thanks.

[tomodachi]

Re: messed up LVDS on a acer 5920

Wouldn't that chip affect VGA output as well?

Thanks.

No it doesn't I guess. But it affects backlight.