Lenovo Z50-70 (NM-A272)

samwigman

New member
I got in a Lenovo Z50-70. It has no video either via HDMI or the laptop display. It comes on with a power light and keyboard backlight. The fan spins only a second at power on and then runs continuously later. I'm not seeing any evidence of liquid damage on the board. I've found a schematic for the board, and it is silk screened. What sort of thing do I want to look for in the schematic relating to no video? I figure there must be some overlap with the Macbook because it's also a Haswell system. Thanks.

https://www.flickr.com/photos/135232461@N04/27118833884/in/datetaken-public/
https://www.flickr.com/photos/135232461@N04/27118844954/in/datetaken-public/

http://www.s-manuals.com/pdf/motherboard/compal/compal_nm-a272_r1.0_schematics.pdf
 

aprendiz

Moderator
Keyboard caps lock responds to keystroke??? put a wired mouse or a USB drive with led and see if it is working... if nothing seems to work, you could try to reprogram bios.....
 

samwigman

New member
I do get the Caps light and a light on a USB drive. Are you saying that precludes the BIOS or that would indicate the BIOS?
 

aprendiz

Moderator
If caps lock and USB drive are working, laptop is working, so the problem is on display , cable or connector...... Use a flashlight to se if you have some image on display....
 

samwigman

New member
There's no image. Do you advise to go ahead and order a screen and cable? I was expecting to see something via HDMI at least with the laptop screen unplugged.
 

aprendiz

Moderator
First check if you hear the Windows startup sound, if you can hear it then, measure voltage on LCD connector and see which one is missing
 

samwigman

New member
I'm not sure if Windows 8 has a startup sound. I never used it. I know 10 does not. I figure if I'm booting up and sitting on the password screen, mashing keys and hitting enter should eventually play the "idiot sound" *thunk* thing. I don't get any of that, though it does read any drive you attach to boot from. I wanted to try Knoppix because that plays a ton of loud sounds on bootup, but I think I'm either having trouble hitting enter at the right time or there's an issue with the BIOS being on UEFI only boot mode because the CD reading eventually stops and i don't get the sounds. I'll have to try Knoppix 7.6.0 once I get a hold of a DVD-R. Should be more UEFI friendly.
 

samwigman

New member
It turned out to be the eDP cable. Thanks again for the helpful troubleshooting procedure. In the future, I'd like to know how to determine whether it's the screen or the cable ideally without buying either. Inquiring in the Tools board.
 
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