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


On Tue, 26 Feb 2008 12:31:53 GMT, in sci.electronics.repair you wrote:

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.

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

On Mar 7, 12:14*pm, (Brad) wrote:
* * *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.

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?