Compaq CQ58 no display/4 blink FIXED!
Had this in yesterday, no display, 4 blinks on caps lock. It was very dirty inside to the point that the fan did not spin at all, so i thought the APU soldering had gone bad. Reballed the AMD E1-1200 APU, no change. Flashed BIOS, no change.
I had a donor board with a known working E450 APU. It is an older generation, yes, but it is the same core (actually it's even more powerful than the E1-1200; that one was the successor to the E350). Same format and everything. I did not know whether it would work but it was the only one i had.
Soldered in the E450 APU and had the same issue. Post card stopped on code F9, same as before. But at least the APU seemed to be compatible as it went thru the same sequence as the original one. Knowing this one was good, i looked further. A big surprise came when i unplugged the LVDS entirely and plugged the VGA in - the screen lit up and showed "Boot device not found". That's what the F9 code was for... Caps lock no longer blinking at this point.
Took apart the display and tested with another LCD. Got video.
. Put the original LCD back on... and got video on this one too. Guess what happened... the LVDS cable was a bit loose at the screen end, and that's what caused the 4 blink issue.
Board booted to Windows just fine with the E450 APU and installed all needed drivers by itself, graphics work no problem. I'll be damned.
So, i have learned two things today. First, you can replace E1 series APUs with the older E series. Second, never rule out simple causes to a complex-looking problem.
Th3_uN1Qu3 out.
I had a donor board with a known working E450 APU. It is an older generation, yes, but it is the same core (actually it's even more powerful than the E1-1200; that one was the successor to the E350). Same format and everything. I did not know whether it would work but it was the only one i had.
Soldered in the E450 APU and had the same issue. Post card stopped on code F9, same as before. But at least the APU seemed to be compatible as it went thru the same sequence as the original one. Knowing this one was good, i looked further. A big surprise came when i unplugged the LVDS entirely and plugged the VGA in - the screen lit up and showed "Boot device not found". That's what the F9 code was for... Caps lock no longer blinking at this point.
Took apart the display and tested with another LCD. Got video.
. Put the original LCD back on... and got video on this one too. Guess what happened... the LVDS cable was a bit loose at the screen end, and that's what caused the 4 blink issue.Board booted to Windows just fine with the E450 APU and installed all needed drivers by itself, graphics work no problem. I'll be damned.
So, i have learned two things today. First, you can replace E1 series APUs with the older E series. Second, never rule out simple causes to a complex-looking problem.
Th3_uN1Qu3 out.
nice one bro 
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