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UPDATE: Dead Compaq Presario 1200XL Laptop/Notebook

Hi,

I found hundreds of postings regarding the Presario 1200XL series laptop with the same or similar problem as I have (see my original post below).

It is my impression that one common cause of this problem is the flash bios going bad. It seems that somehow, there is a connection with a dead RTC/CMOS battery and flash bios!!! I replaced my dead RTC/CMOS battery (like many others did), but that isn't enough.

I read several reports that stated the laptop was brought back to life after the flash bios was replaced, along with a new RTC/CMOS battery.

My impression is the 1200XL series is a LEMON or this was designed into the system so the laptop last for as long as the RTC/CMOS battery?

I am a TV, etc. service tech and I know that the contrast/picture setting from the factory is often set to maximum. The end result, this shortens the life of the picture tube, therefore reducing the life of the TV.

Brad

Hi, > > My Compaq Presario 1200XL laptop/notebook won't power up (dead). > > Note: I service TVs, etc. but not computers except my own. > > I checked the power micro switch (AOK). I removed the >battery, then tried to power it up again the next day without >installing the battery. Also, I used a bench power supply set >at 19Vs as a sub for the AC adapter with the same results. >I checked the 5 amp fuse on the mother board. > > When I press the power button/switch, there is absolutely no sign >of a response (reason I checked micro switch). > > The only indicator that lights is the one that shows the AC adapter >is plugged in. > > If I could get my hands on a schematic, that will be a big help. > > Thanks in advance, Brad > > Before you type your password, credit card number, etc., > be sure there is no active keystroke logger (spyware) in your PC.
Reply to
Brad
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Hi!

I've heard that some motherboard makers programmed their NVRAM chips for the first time with "special" information that the board itself could not reset/restore if power were ever lost.

I wonder if Compaq (or, more likely, the OEM that built it) decided that using battery backed RAM to store the BIOS was cheaper than a real ROM.

William

Reply to
William R. Walsh

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Your symptoms of no power are similar for maybe 100 different failures. So was that CMOS battery defective? Don't replace any battery without first measuring it while still attached. Having not done so, then 1) we don't even know is the battery was defective and

2) can only wildly speculate that a battery has any affect on your problem.

No, flash memory would have no relation to the battery. How flash memory works would have made that obvious. Far more useful would be numbers such as from the main battery. Does main battery charge when AC power is connected (and computer is off)? Now we have useful information to understand what actually exists.

Apparently power is getting into the system - indicated by a flashing light. Will system boot from battery? Is battery charged (another use for the meter)? Computer power from battery involves circuits different from AC power which are different from circuits that charge the main battery. Which circuit (may) have failed?

Reply to
w_tom

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