I have been given an old DV6-2007EL HP Laptop (AMD Turion 2- M500 cpu & ATI HD4650 VGA)
The laptop shows a random problem: sometimes it correctly starts and load the OS, some others it just doesn't turn on, but:
Option a) All the leds are OFF; the fan works; if there is a CD the CD-Drive spins; black screen;
Option b) Bloc maiusc and Bloc scorr leds blink twice, then pause, then blink twice again, and so on. Again, the fan works, black screen (nothing appear on the screen)
Option c) Bloc maiusc and Bloc scorr leds blink without any pause. Black screen, fan spins, etc.
All the above appears on a totally random sequence. Bios has been updated from 009 to 013 version, but the problem still persists.
Laptop has been then opened, fully cleaned, thermal paste has been replaced (it was hard as cement....), CMOS battery replaced (I had one available, so ...why not?)..but exactly the same issue.
I also tried another power supply as I had it available , but same results . I guess it's a random BIOS problem (perhaps, a partially corrupted memory block?) .
Any idea or hints?