Black screen - can't find CMOS

[thomashj]

Hi everyone,

This is my first post. Hope I put it in the right place. I'm generally quite good with computers, but having some problems now.

Friend's laptop (Medion S14409 -MD62133) seems to work (power, lights, fans working, etc) but the screen stays black. And it's hard to troubleshoot a black screen. So no access to BIOS/UEFI. Tried a lot of things.

- removed the battery (seems fine, holds charge)
- removed RAM-memory strips (no problems)
- removed internal M2 SSD (worked well in another pc)
- connected an external monitor (no joy)

Can't seem to get anywhere so figured I would try removing the motherboard / CMOS battery.

But I can't for the life of me, find it. By now I have taken apart quite a lot of parts from the laptop but still can't find it. I'm hoping removing and putting back (or replacing) the CMOS battery will do the trick, but well.. I need to find it first.

I'll add a photo of the inside of the laptop in case it helps.

If the batery isn't going to help then my next guess is drivers for the GPU or a busted GPU which would surprise me.

Any help is much appreciated.

 

[rgd1101]

did you test with external monitor?
did the laptop turn on?

 

[thomashj]

did you test with external monitor?
did the laptop turn on?

hi, thanks for your response. Yes, as stated in my post, I hooked the laptop up to an external monitor (via HDMI) but without succes. No image on the external screen either.

 

[thomashj]

So.. some extra information. Have been trying some more and found what looks like a reset-button on the laptop's oustide/casing. A small pinhole with a rounded arrow beside it. Similair to the hole you'd find on a smart phone to open the SIM-tray. Used this to try and reset the CMOS. No idea if id did much. It didn't solve the problem of the black screen. ANy help is appreciated.

 

[rgd1101]

where did you see the power and light working?
sound like system board issue

 

[thomashj]

The power light on the side of the laptop goes on, indicating the fact that the laptop is working. Both fans are also running.

My gut felling telsl me it might be a problem with BIOS/UEFi trying to read from the wrong bootdevice or maybe some software-problem as a result of windows update causing the black screen. I once had a similair problem with my desktop and it turned out to be a problem with the GPU driver.

 

[thomashj]

I tried booting from a external bootable USB-drive. Nothing. Screen stays black.