State of the Art engineering

Computer Nerd Kev

2024-04-05 23:16:18 UTC

Post by Don Y
A friend brought me a laptop that is beeping, annoyingly
(like set volume to max). Continuously.
Google tells me this means "CMOS battery failure".
Wow! What idiot engineer thought this was such a significant
event that the laptop should beep FOREVER (before and after
"CMOS battery failure; Press F1 to continue"
If having the correct time is so important, perhaps he
should have inhibited the boot process UNTIL the battery
had been replaced! Wouldn't want some poor slob to
have to work with a laptop that is displaying the wrong time!

There are some laptops that get their BIOS settings so wacky once
the battery gets low that they become unstable and have weird
crashes or boot errors. Thinkpads had that trouble (both IBM and
Lenovo), a seemingly obvious hardware failure was actually just a
dead battery. But at least IBM Thinkpads made them a pretty quick
and easy job to replace.

Once the BIOS has detected it though, it should be able to reset
to sane defaults. The beeping is usually for when the CPU can't
run (faulty RAM, etc.) and therefore can't display the errors on
screen, so my guess would be that there's a bug in the BIOS code
that triggered the wrong error reporting mode. Or maybe they were
too lazy to have more than one error reporting mode.

The real question is why manufacturers didn't switch to using
rechargable batteries for this. Some laptop makers did in the 90s,
but the trend reversed by the 2000s. For laptops as recent as the
one in the video they could've used flash for the settings and a
supercap to keep the time for the rare periods when the battery is
removed or completely discharged. I suspect planned obsolescence.

Post by Don Y
http://youtu.be/shrPQDtoniA
TL;DR... completely disassemble the laptop to EXPOSE
the battery for replacement. Likely the same idiot
engineer who decided it should beep endlessly ALSO
decided to locate the battery in such a place that
it can only be accessed by complete disassembly
(even though a little "access opening" BEHIND the
removable service panel would have done the trick!

Yes it's amazing how well some manufacturers burry the damn things.
Sometimes there _is_ a service opening to the bottom of the laptop
motherboard to access the RAM, but they decided not to make the
battery accessible from there, so you have to pull out everything
to access it from the top down. Again I suspect planned
obsolescence.

Post by Don Y
Um, no.
"Sorry, Bob. I don't plan on spending an hour just
to replace a disposable battery! Maybe you can
find the speaker wires and CUT those!"

That's a shame. I actually quite like replacing those batteries in
laptops. It is also a good opportunity to clean it out and check
for corroded connections. I bought a small tray of solder-tab
CR2032s and I'm getting near the end of them now.

Mind you I prefer to do it on laptops of my own, that I want to use
or sell on Ebay, because it can be very hard to get some of the
clip-together cases apart without visibly damaging them. Especially
those where the manufacturers keep their service manuals top
secret.

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