acer 5734z freezes at acer logo

Hi everyone, I bought an used Acer 5734z that freezes on Acer logo. I changed ram, cpu, power charger,......everthing. I removed cd rom, hdd, wifi and nothing happened.
Everytime it turns on, i tried to access to bios pressing F2 and itfreezes again.............I turn it on and I press Esc key and shows bios post and freezes again!!!......I decided to upgrade bios.......but when it starts the bios flashing process (obviously pressing fn+Esc before plug the power charger and turn it on) the notebook turns off and I cant turn on if i dont unplug the power charger.
Suggestions? I tried using the latest bios, the first one, all software includded, only the .fd file.......is all the same......it turns off!!!

Ova Nadal said:

I cant turn on if i dont unplug the power charger.

Click to expand...

Do you mean that the computer does something different when you run it on battery power only?

not exactly, what i mean is that when it turns off by itself, i have to unplug the psu to turn it on again.
Now I found something interesting!!!
Trying to recovery the bios flash memory with an old 4gb mp3 player as a pendrive, The laptop turn on with the fan cooler running at full speed. And it turns off too!! but 5 minutes later. Then I turn it on again (unplugging the psu and re pluggin) but the bios (1.01) is the same old version. I've tried 1.02, 1.05 and 1.06 versions.

Vacuum dust yet?
inspect heatsink?
Reset BIOS yet? reduce FSB?
Try MEMTEST86+ on a burned CD to boot from or any live Linux yet?

Perhaps aging latent fault, means end of the road.

no dust, everthing is clean, heatsink works fine, cant reset bios, cant access to bios, cant boot memtest, cant boot anithing.......stucks on acer logo. before detect hard disk and cd rom...........even if u remove it hdd or/and cd rom

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i'm going to find another same version of 5734z acer. just to remove bios chip and re soldering the new one. Did i mentioned that i'm electronic level technician?

Ova Nadal said:

The laptop turn on with the fan cooler running at full speed.

Click to expand...

Maybe this happens for a heat-related reason? A short-circuit? Or too much current flowing, to cause a drop in power supply voltage? Such things do not always cause a total shutdown, but maybe a system hang.

Ova Nadal said:

no dust, everthing is clean, heatsink works fine, cant reset bios, cant access to bios, cant boot memtest, cant boot anithing.......stucks on acer logo. before detect hard disk and cd rom...........even if u remove it hdd or/and cd rom

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i'm going to find another same version of 5734z acer. just to remove bios chip and re soldering the new one. Did i mentioned that i'm electronic level technician?

Click to expand...

even with 5 minutes over cooler?
Does POST pass? hit ESC or go to BIOS

if Post fails then isolate problem by removing RAM , 1 at a time, press on MOBO parts gently to check bad solder joints.

LOGO is a bios option often defeated with ESC.

hello have solved your problem ?? if not then try this one check with keyboard and touch-pad connector removed if it pass post then your keyboard is faulty.