Blank screen on boot (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.

Responses(2)

B

bladteth

4 Posts

0

September 3rd, 2020 15:00

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.

JA

just a human

13 Posts

0

August 17th, 2020 12:00

I've been having the same problem.

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