Hi Ken,

The laptop is "totally dead". Absolutely nothing happens, not even the
faintest "tick" when you press the power button. The first time this
happened, I opened the laptop and bridged the "Power" button switch
with another, thinking it might be the power switch.

Brad

On Thu, 05 Mar 2009 06:50:42 -0600, in sci.electronics.repair you wrote:

David Nebenzahl wrote:
On 3/4/2009 4:46 AM Ken spake thus:

Brad wrote:

I have a Compaq Presario 1200XL laptop computer that one day, would
not power up. I tried another power supply, replaced a dead RTC/cmos
battery, etc. I removed the RTC battery, main battery, and
put it away. A month later, I decided to try it again. It powered
up! Everything seemed just fine, but it only lasted for a couple
days before it happened again. Again, I put it away. A month or so
later, it powered up and again everything seemed just fine. I
downloaded ROM Paq SP15611 and I "flashed" the bios. About a day
and 1/2 later, the laptop "died". Now it won't boot up. Again after
a long rest period, it came back to "life", but for how long? Note:
It won't power up after a week's "rest", but it will power up after
a longer rest such as a month!

If it were my computer the first thing I would do is clean the
contacts of the RAM. It sounds a lot like a bad connection and the
RAM is essential to it booting to even a bios screen for most
computers.

True, but it's hard to see how that would explain the bizarre behavior
the O.P. reported (what, do the memory chips magically unseat
themselves, then reseat themselves in the interval?).


I assume your question is since Any contact is subject to
interruption, even those using gold to prevent corrosion. Temperature
changes often are enough to move such contacts and provide an
intermittent contact. It really is not magic at all.

I cannot say definitively that this is his problem, but that is one
area I would eliminate before suspecting others. It would also be nice
to have an explanation of exactly what is happening with respect to his
failure to boot.

(Brad) wrote in
:

Hi Ken,

The laptop is "totally dead". Absolutely nothing happens, not even
the
faintest "tick" when you press the power button. The first time this
happened, I opened the laptop and bridged the "Power" button switch
with another, thinking it might be the power switch.

Sounds like a (in order of decreasing probability
'bad solder connection'
bad component (capacitor, IC, diode, transistor, inductor, resistor) that
may have an internal connection that opens up under thermal stress and the
stress only slowly relaxes, allowing the connection to make again.

Suggestion: chill various areas while cycling the power.

Alternate suggestion: chill the whole computer (put it in a zip lock back
and put it in your refrigerator over-night, take it out the next morning
and allow it to warm to room temperature before opening the bag [to prevent
water condensation]). This may allow you to 'reset' the computer more
rapidly.





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

Alternate suggestion: chill the whole computer (put it in a zip lock back
and put it in your refrigerator over-night, take it out the next morning
and allow it to warm to room temperature before opening the bag [to prevent
water condensation]). This may allow you to 'reset' the computer more
rapidly.

pretty method, i will consider it maybe...
but the 'nine proof' for bad connection can be when it powers up try to hit a bit it around,
try to stress it to find bad connect. or bad soldered BGA chips..
let us know.. after that open the freezer and let it make frendship with chickens or fishes...