HP Omen 15-dc0025ca

[bobtheflyguy]

Have searched the boards and tried various topics with no luck.

Laptop shutdown, thought battery was dead.  When plugged in just black screen on POST.

there is a backlit screen.  Ironically had just installed a new wlan card and did a bios update to F.19 from F.18.  Bios update no issues and rebooted fine and was using computer for several hours no isssues.

when I try the BIOS recovery, win+V,  it will only display the checksum invalid (502) error message on the screen.  On restart nothing happens and black screen loop.  Every time I try keep getting same message.   Caps lock does not have a flashing hardware code.  

can press the keyboard function +F4 and keyboard backlighting works,  same with the function light on key f12.

usb recovery stick will not load.  Tried all 3 usb ports.

have tried,

replacing old wlan card, removing wlan card all together

removing ram all together. 2x sticks,   Get flashing caps error code with all ram gone.  Will not load win+v 

tired each stick independently.  One stick in slot one gives a 3 long 2 short caps lock code.  Removed this from the board and the other stick no error code.  Looks like original ram no good?

using only 1 stick with no flashing code.   Win+v same error (502), endless loop no success.  Win+b doesn’t seem to do anything with this model.

have removed HDD,wlan card, ssd drive, no change and battery running with just ac power cord.  No cmos battery internal built into battery.

on 502 error restart both fans turn on and go to a high speed setting.

,  it screen remains black

where to go from here to reflash the BIOS?  Followed the HP bios recovery faq, no success.  Tired the old tricks like  external video etc no success, 

have HDD currently removed trying to reset bios, does this need to be installed? 

[bobtheflyguy]

*****SOLVED*******

After some more research I found the problem to be with the #1 ram slot.  

Came across a YouTube video 

https://www.youtube.com/watch?v=DeC3PxBKUoM

solution was to use toothbrush and compressed air to clean out ram slot.  the pins are too small for me to check for movement.

After, started to install parts one by one and all worked and back into windows after a single 502 error messsage with a bios reset.  About 30 seconds after power on,  no win+v key required, 

Previously, with two ram sticks no caps lock light message.  With one stick in slot 1 got cap lock light flashing.  

After cleaning was able to complete UEFI memory test and the single stick that showed failed before passed.

reinstalled an AX210 v.pro wifi card and was able to get it working even though not showing on service manual support list.