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Compaq Laptop: Not booting: Black screen: No BIOS
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Posted December 18, 2012 at 8:34AM
My 4 years old Compaq Presario c700 (C794) laptop is not booting up. Does not go into BIOS, and does not even show the message “Press F10 to enter BIOS” etc.
I see a clear black screen (but has backlit and I am able to adjust the brightness using Fn keys). Tried on the desktop monitor, it is black too.
The HD is running intermittently, all LEDs are on, and the fan is running.
Windows is not booting up, there is no log on sound. WIFI light is also orange, it becomes green after booting is complete. HD activity is on but it is not as much to boot up Windows 7.
Troubleshooting I did till now:
- Hard reset by holding down the power button several times.
- Cleaned RAM and placed it in another slot.
- Removed the power and battery and kept it overnight.
- Tried on the desktop monitor, it is black too.
This happened all of a sudden. I did not do any BIOS updates or anything that normally causes these kind of problem. I learned from some forums that an exhausted CMOS battery can cause it. Is it true? In this case, can you please give the location of the CMOS battery in these laptops?
What are the other measures I can take?
Likes # 0
Posted December 18, 2012 at 8:53AM
I doubt it's the CMOS, but if you want to try, there is a service manual here. More likely to be the graphics chip, I would have thought.
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Posted December 18, 2012 at 9:10AM
Thanks for the manual.
I thought it could be the Video card, but there is no sign of Windows booting up. I tried another monitor, it was black too.
Likes # 1
Posted December 18, 2012 at 11:30AM
'Video card, but there is no sign of Windows booting up'
Exactly - because the screen stays black, and the same with a separate monitor, that's why I think the graphics chip is the most likely culprit.
Likes # 0
Posted December 18, 2012 at 5:42PM
Make sure nothing in DVD drive
Disconnect all usb devices / cards
Remove HDD and see if it boots to an error message
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Posted December 18, 2012 at 6:15PM
as above try booting to bios with hard drive removed
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Posted December 19, 2012 at 6:14AM
Thanks for your suggestions.
Last night, I removed the RAM and tried to boot. I could not hear any beeps as I was expecting. But the glow (backlit) of the screen was gone. I restored the RAM and the backlit was back.
I will remove the HD today and see.
Likes # 0
Posted December 19, 2012 at 6:14AM
Thanks for your suggestions.
Last night, I removed the RAM and tried to boot. I could not hear any beeps as I was expecting. But the glow (backlit) of the screen was gone. I restored the RAM and the backlit was back.
I will remove the HD today and see.
Likes # 0
Posted December 19, 2012 at 9:19AM
Old remedy worth a try.
Unplug the power, remove the battery and then hold the power button for 30 to 60 seconds. Then reattach the power and attempt a boot.
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Posted December 31, 2012 at 6:44AM
Laptop is working after CMOS reset. Thanks for all your suggestions.
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