Blank screen on boot issue (Dell Inspiron 17R SE 7720). How to revive?

Hi,

My old Dell Inspiron 17R SE 7720 was becoming increasingly erratic at boot in the last few weeks. Right now, when switched on, it powers up, LEDs light up, but the screen remains black/blank. When connected to an external display via HDMI or VGA, nothing is displayed either. However, screen seems to be working fine and passes self test when D+power is pressed at boot. Occasionally it will initiate ePSA self-check when I keep pressing Fn+power. Apart from OEM battery, all components pass the test fine, even the extended stress tests:

https://drive.google.com/file/d/1Gca_NwI6EqI_u0tbWo-rv_vxEl7d56KD/view

Battery is not original and about a year old. The laptop behaves in the same manner with battery removed. I took it apart completely, disconnected and reconnected all cables, reseated memory modules and CPU, repasted processors, but the issue persists. The radiator was somewhat badly clogged with dust. BIOS identifies all components fine if I manage to enter it once every 10 or so boots. There are no signs of any damage, burns or other blemishes on motherboard or chips.

Any suggestions?

Thanks.

 

Hi, is this the 3D display ? Is the GT650M okay in windows ?

 

It's a standard, non-3D display. I managed to boot into Windows and everything seemed to work absolutely fine.While stress testing the components using Prime95 and FurMark, I could not see any errors. CPU heated up to 90C, but did not throttle, GPU started to downclock very slightly when it reached the same temperature after several minutes. When I put the computer into sleep mode form OS, it wakes up fine. However, I've just shut it down and again, same issue as before - blank screen.

I thought I would give BIOS reflash a shot. Attempt from OS ended up with message "ERROR 216: Failed to read BIOS from ROM! Status = 1604" and update stopped. I created USB bootable stick, copied extracted BIOS file and performed End+power cord trick. Same error. I tried several times with same outcome. It looks like BIOS chip on motherboard is corrupted or on the way out and needs replacing.

 

Problem solved! If you experience this issue, it looks like BIOS is corrupted and chip needs to be replaced.

Solution:

1. Get a new chip Winbond 25Q64FVSIG (very cheap on eBay)
2. Download .bin BIOS file from this forum: https://www.badcaps.net/forum/showthread.php?t=31849
3. Program the chip or have it programmed (some sellers on eBay do it free of charge)
4. Remove the old chip and solder new one to the motherboard (requires almost full disassembly of the laptop)
5. Update BIOS to the latest A17 downloaded from Dell website

Soldering might be a bit tricky as the chip is located very close to plastic connectors (keyboard) and other tiny components on the motherboard. I'd advise against using heat gun. Location of the chip:

https://drive.google.com/file/d/1czjB5f4cwN0L5oqnF-R99OzAZRE-g2Ma/view?usp=sharing

The chip:

https://drive.google.com/file/d/18nYAaaX9QvraWKPB4EbGeGnfiHOaK15f/view?usp=sharing

There is only one side effect I've noticed so far. The laptop identifies with a different Service Tag, which must be stored in BIOS chip. However, this does not affect the functionality at all.