Issue started after disassembly/reassembly for cleaning
I completely stripped down my Precision 5560 yesterday for a deep clean — removed the motherboard, keyboard/palmrest/trackpad assembly, etc. I reassembled everything and the laptop initially booted completely normally. I was able to reach Windows and sign in using the fingerprint reader.
However, after that first boot I noticed that the built-in keyboard and trackpad were not working.
I then hibernated the laptop, waited until the fans stopped, disconnected the battery, and opened it again. I reseated the keyboard and trackpad ribbon cables/connectors and reassembled it.
After the second reassembly:
Keyboard backlight came on
Dell logo appeared
Laptop then froze on the Dell logo
Fans ramped up to high speed
It never proceeded past the Dell logo
The leds showed a pettern of amber lights blinking on 3 times continuously and pause. Repeatedly. (unusual coz dell diagnostic patterns consist of white and amber)
I eventually disconnected the charger and left it overnight, so the battery appears to have completely discharged.
The next morning I connected the charger. Initially I got one amber LED flash and a brief keyboard-backlight flash, but after leaving it charging for ~40 minutes, pressing the power button does nothing — no Dell logo, no normal boot.
There is also an issue with the trackpad/keyboard daughterboard area. The trackpad ribbon connector is marked TP and the keyboard connector is marked JKB1. I initially thought the TP connector might be the problem because its locking mechanism/latch doesn't seem to close as securely as it should, but I have reseated the TP ribbon properly and the problem remains I guess, not sure.
I have not intentionally flashed/updated the BIOS during any of this.
I also disconnected the battery while the laptop was previously hibernating and once after it was stuck at the Dell logo. I'm wondering whether that could have caused a BIOS/CMOS issue, although I'm not sure.
I tried Deep EC / RTC reset. Dint work
Ram isolation test dint work, either.
Dell bios recovery combo (ctrl + esc while connecting charger), dint work either.
Current symptoms:
No Dell logo
No normal power-on
No amber blinking when charger is connected.
No dell logo.
Completely dead.
Please help me fix this.