"Remember that one bug that had you tearing your hair out and banging your head against the wall for the longest time? And how it felt when you finally solved it? Here's a chance to share your greatest frustration and triumph with the community.
One that I vividly recall occurred back in the early 90's at a startup that was developing custom PBX hardware and software. There was the current development prototype rack and another rack for us in Quality Assurance (QA). Our shipping deadline for a major client was fast approaching, and the pressure level was high as development released the latest hardware and software for us to test. We soon discovered that our system would not boot up successfully. We were getting all kinds of errors; different errors each time. Development's machine booted just fine, *every* time. We swapped out our hard disks, the power supply, the main processing board, the communications boards, and finally the entire backplane in which all of these were housed. The days passed and the system still failed to boot up successfully and gave us different errors on each reboot.
What could it be? We were all stymied and frustrated as the deadline loomed before us. It was then that I noticed the power strips on each rack into which all the frames and power supplies were plugged. The power strip on the dev server was 12-gauge (i.e. could handle 20 amps) but the one on the QA rack was only 14-gauge (15 amps). The power draw caused by spinning up the drives was just enough to leave the system board under-powered for bootup.
We swapped in a new $10 power strip and it worked perfectly. And we made the deadline, too! So, fellow Soylents, what have you got? Share your favorite tale of woe and success and finally bask in the glory you deserve."
I've had a few gotchas that really took some digging to figure out. First was a customer who insisted that his dedicated server was being hacked. I kept having to restore /etc/, /bin/ many other directories. They were *gone*. The third time it happened, he admitted that it might have been something he was trying to do with his server. He was running a shell script. And in it was the command "rm -rf /usr/home/foo /usr/home/bar / /usr/home/fubar/". Whoops.
Then there was an old lady who swore her computer was hacked, the mouse kept moving while she was typing. Other techs had scanned the machine several times and declared it clean. I asked "is this a laptop?" (mind you this was over the phone) and it was. I showed her how to disable the touch pad that she kept bumping.
Another one also involved an older person and a mouse. There was something definitely wrong with their computer. Programs wouldn't open, nothing acted right. It worked fine for me until I realized that I was having to POUND on the mouse to get it to click. I convinced him that a new mouse was needed, and that was that.
There are others too, long and drawn out ones that I just don't remember.
But there is one that I most definitely do. I was doing onsite computer repair for an outfit in Reno. A rather difficult customer had us out to do some work, and in the midst of it, she wanted her DSL modem and router moved from below the desk to above it (or vice-versa). The modem lit up, the router lit up, she was able to get online.
The next day she called. Her Internet was not working. Since I had just been out there, I suggested she call the local telco. She did, and they insisted everything was fine on their end, and I believed them. I went out there a total of 3 times. The third time, I was on the phone with the telco to tell them how dumb they were, when something struck me. I unplugged the power from the modem and router, swapped them, and plugged them back in.
They were both 12V and the same polarity, and same connector. They were *very* different amperes. One was almost 2A and the other only 500mah. She was online with no further troubles. I reversed them when I moved them!