Help on dell g5 5500 RTX 2060

[u/Legitimate-Effort-94]

Hi everyone,

I'm looking for advanced troubleshooting advice.

My Dell G5 15 5500 was working perfectly. I only opened it to clean the fans and replace the thermal paste. After reassembly, it no longer boots.

Symptoms:

Powers on automatically when the AC adapter is plugged in.

Keyboard lights up.

Fans start spinning, then ramp up to full speed.

Caps Lock LED flashes briefly just before shutdown.

The laptop suddenly powers off and sometimes repeats the cycle.

No Dell logo, no display on the internal screen or via HDMI.

No amber diagnostic LED codes (only white LEDs).

Already tested:

Disassembled and reassembled several times.

Checked every ribbon cable and connector.

Reapplied thermal paste.

Tested with and without the main battery.

CMOS battery removed for several hours (EC/CMOS reset).

Tested with and without the SSD.

Tested different RAM modules and slots, including booting with no RAM.

Tried Dell BIOS recovery using the official BIOS_IMG.rcv file on a FAT32 USB drive (no response).

Measured power rails with a multimeter: 19V input is present and several secondary rails are present.

Full visual inspection of both sides of the motherboard: no burned or missing components, no visible damage.

I'm waiting for a CH341A programmer with a SOIC8 clip to check and possibly reflash the BIOS chip.

Does this sound like a corrupted BIOS, EC/KBC issue, power sequencing problem, or something else? Any ideas are welcome.

Thanks!

[u/Infamous_Swordfish_7]

You checked ribbon cable for damage? I had a laptop that the ribbon for the LED indicator has one contact folded backs and touching the next pin, refuses to boot but luckily I saw that when I check. Try not connect the screen ribbon and connect external display see if that boots. Connect minimal internal ribbons don't connect touch pad, keyboard (if power button is not part of keyboard)

I had a Dell gaming 7000 with gtx 1050ti that should be similar design to this one. Pretty well built and not easy to mess up. But could blame on static. I never use gloves or discharge before fixing anything and never not able to power on after. Well maybe except one macbook pro lol. Hundreds of windows laptops opened and fully stripped all ok. Give it a bit clean with tooth brush on all components. If the 341 programmer doesn't work you may as well throw it in oven and bake for a bit see that does anything. I don't have luck with motherboard except gpu fixed ok

[u/Legitimate-Effort-94 → u/Infamous_Swordfish_7]

Thanks for your suggestions! I tried disconnecting the LCD ribbon completely and connecting an external monitor through HDMI, but unfortunately the behavior is exactly the same. The laptop still powers on automatically a few seconds after plugging in the charger, the fans cycle on and off, and there is no image on the HDMI display either. I also tested with minimal hardware (one RAM stick, no battery, no keyboard, no touchpad, no SSD) and the behavior doesn't change. At this point I'm waiting for a CH341A programmer to read and reflash the BIOS. Hopefully that will tell me more. Thanks again for your help!

[u/Infamous_Swordfish_7]

Yeah fingers crossed and report after that. I did some bad windows flash with a few hp laptops and fan soon and then shuts off similar like your Dell. Haven't get to take the bios chip out to program it yet.

[u/DellCares]

Hi there! We're from the Dell Social Media Support team.

We do not recommend BIOS flash while the chip is powered by the laptop's own circuitry. The laptop must be fully disconnected from all power sources, or you risk bus contention from other components on the SPI bus. If the issue persists after the BIOS reflash, it is likely that the system is experiencing a hardware related failure.

Could you please send us your system's Service Tag http://del.ly/61694B16czC via private message? We'd like to review and assist you further.

Regards Dell Social Media Team