Dead Laptop comes back to "Life" Mystery

Hi,

I have a Compaq Presario 1200XL110 laptop (bought 2nd hand) with
bad display (display "wires" disconnected). I used an external Monitor. I
kept the laptop plugged into AC all the time and the battery installed. I
had no problems the first few days. Note: the laptop was on from 7:30AM
until around 5PM every day. Then one morning, I tried to turn it on, but
absolutely nothing happened. The only indicator that was lit, which
is always lit, is the plugged into AC indicator. Note: I am a TV, etc. (not
computer) serviceman. I won't go into details of the tests I performed, which
included testing the power switch.
.
I removed a dead (!!) RTC/CMOS battery. Note: When the laptop "worked",
there was no sign (loss of time/date) that the RTC/CMOS battery was going bad.

I put this laptop in a box (main battery removed). About 5 days later, I
hooked it up to AC, but left the main battery out (RTC/CMOS battery removed).
When I tried to turn it on, absolutely nothing happened so I put it back in
the box (main battery removed).

Over a month later, I hooked up the laptop (main battery removed & no RTC
battery). When I pressed the power button, it booted up!!!!!!! I repeated
shut down and power up. It boots up every time, although I see a warning
message caused by no RTC/CMOS battery. I installed a new RTC/CMOS
battery. I now use it on AC without the main battery installed. When I shut
it down for the day, I remove AC power via the switch on the power strip.

Can someone explain this MYSTERY???

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.

Mike
Wed Apr 23 07:10:51 PDT 2008

Well, one trick with computers is to take all the batteries out and then try
to turn them on. When you do that, you sometimes can FORCE any
residual charge left in caps and such to drain off. I've had to do that to
my old LG cell phone occasionally. Sometimes you have to hold the
power button down on the phone to force a drain. Then put the battery
back in and it would start first try.

Sound like it could apply to your situation?


"Brad" <bpetria@verizon.net> wrote in message
news:480f1fec.409930@news.verizon.net...
> Hi,
>
> I have a Compaq Presario 1200XL110 laptop (bought 2nd hand) with
> bad display (display "wires" disconnected). I used an external Monitor.
I
> kept the laptop plugged into AC all the time and the battery installed.
I
> had no problems the first few days. Note: the laptop was on from 7:30AM
> until around 5PM every day. Then one morning, I tried to turn it on, but
> absolutely nothing happened. The only indicator that was lit, which
> is always lit, is the plugged into AC indicator. Note: I am a TV, etc.
(not
> computer) serviceman. I won't go into details of the tests I performed,
which
> included testing the power switch.
> .
> I removed a dead (!!) RTC/CMOS battery. Note: When the laptop
"worked",
> there was no sign (loss of time/date) that the RTC/CMOS battery was going
bad.
>
> I put this laptop in a box (main battery removed). About 5 days
later, I
> hooked it up to AC, but left the main battery out (RTC/CMOS battery
removed).
> When I tried to turn it on, absolutely nothing happened so I put it back
in
> the box (main battery removed).
>
> Over a month later, I hooked up the laptop (main battery removed & no
RTC
> battery). When I pressed the power button, it booted up!!!!!!! I
repeated
> shut down and power up. It boots up every time, although I see a warning
> message caused by no RTC/CMOS battery. I installed a new RTC/CMOS
> battery. I now use it on AC without the main battery installed. When I
shut
> it down for the day, I remove AC power via the switch on the power strip.
>
> Can someone explain this MYSTERY???
>
> 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.
>

philo
Wed Apr 23 10:28:38 PDT 2008


"Brad" <bpetria@verizon.net> wrote in message
news:480f1fec.409930@news.verizon.net...
> Hi,
>
> I have a Compaq Presario 1200XL110 laptop (bought 2nd hand) with
> bad display (display "wires" disconnected). I used an external Monitor.
I
> kept the laptop plugged into AC all the time and the battery installed.
I
> had no problems the first few days. Note: the laptop was on from 7:30AM
> until around 5PM every day. Then one morning, I tried to turn it on, but
> absolutely nothing happened. The only indicator that was lit, which
> is always lit, is the plugged into AC indicator. Note: I am a TV, etc.
(not
> computer) serviceman. I won't go into details of the tests I performed,
which
> included testing the power switch.
> .
> I removed a dead (!!) RTC/CMOS battery. Note: When the laptop
"worked",
> there was no sign (loss of time/date) that the RTC/CMOS battery was going
bad.
>
> I put this laptop in a box (main battery removed). About 5 days
later, I
> hooked it up to AC, but left the main battery out (RTC/CMOS battery
removed).
> When I tried to turn it on, absolutely nothing happened so I put it back
in
> the box (main battery removed).
>
> Over a month later, I hooked up the laptop (main battery removed & no
RTC
> battery). When I pressed the power button, it booted up!!!!!!! I
repeated
> shut down and power up. It boots up every time, although I see a warning
> message caused by no RTC/CMOS battery. I installed a new RTC/CMOS
> battery. I now use it on AC without the main battery installed. When I
shut
> it down for the day, I remove AC power via the switch on the power strip.
>
> Can someone explain this MYSTERY???
>

>rare<
I have seen a few machines act erratically with a cmos voltage around 2.3
volts or so.
A low but not completely discharged cmos battery could conceivably hold the
bios in an illogical state.

If you still have the old battery...
measure the voltage