Bad Caps then
We've all heard about the
Bad Capacitor
phenomenom. For some reason, some companies have made batch after batch of faulty capacitors. And it's hard to
tell which is bad or which is good. The only test is to use them on your boards.
In the old days, I purchased two HP E-PC ultra compact PC's for a very low price. Never heard of bad caps in
those days. And even IF I would have known it, I would have thought that a major brand like HP would certainly
buy only trusted US caps. How wrong can you be. HP had already done a major E-PC mainboard swap in the years
before. And the large number of E-PC's that appeared in the dump shops (and on Ebay) all had the old mainboards.
My first E-PC died after a year of normal use. Initally it did everything, only the NIC refused to work. And
in the next weeks, each few days, one more error popped up. Powering down became a matter of pulling the plug.
Until, suddenly, the machine was dead. The CPU was good. The power supply was good. All peripherals were good.
LED's glowed. And nothing worked. And none of the caps was bulging. I put the machine aside for a while but
could not find any real cause. So I took out all usable parts and dumped the rest at the waste dump, better
known as 'Ebay'.
Bad caps now
A few weeks ago two of my customers complained about a dead Longshine LCS GS8208 managed gigabit switch. In
both cases, the power supply was dead. In both cases, the power supply capacitors were bulging to the edge of
vomitting their contents over the board. I replaced the caps and the power supply was fine again. Bad caps! In
equipment manufactured in 2009! Apparently these were now made and not in one or two batches from around the
millenium change. It more looks like we reached the limits of what a capacitor can take. We call it bad caps,
but I think it's more like over stressing caps.
Another case of bad caps was my
Beryllium
PC. I got it around 2005. It became operational with Debian Sarge. But suddenly the system started to behave
erratically when I switched screens (it was on a Cybex Switchview hardware screenswitcher) back and forth
between computers. The system would hang and after a reboot the VGA subsystem would lock up. The computer then
needed a 15 minute rest (all power removed) and it would start again as if nothing had happened.
For some reason I needed a newer webbrowser and the easiest way to to that was by installing Slackware 12.2.
With the Slackware VGA drivers things were a lot better. All went well, until, all of a sudden, certain
software refused to run. Kbounce and Eagle CAD. I learned to live with that. But it was a bit of a nuisance.
One friend blamed it on bad caps. But I have never understood why software would not run because of a
capacitor.
A few weeks ago, my hard drive started to (occasionally) produce a clunky click... Oh no, not the
So I took my spare computer (more powerful than Beryllium) and put the Beryllium HDD in it. I changed the boot
sequence and crossed my fingers. Now Beryllium runs inside another system. The disk does not click anymore.
Kbounce and Eagle CAD work just fine! And upon inspecting the old Beryllium system (an Asus Pundit) I noticed
two capacitors that were bulging. Bad caps! In a premium brand computer system!
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