Fixing things

Post date: Apr 25, 2011 7:20:44 AM

I have always liked to take things apart and put them back together. I started fixing laptops and delecate electronics and over the years, I have gotten pretty good at troubleshooting.

Here are some of the more memorable repairs:

When I was 14, I wanted a cell phone, so I went out and got a cool new Mitsubishi G310. Being the geek I am, I wanted it to be different then anyone else's cell phone. Sure, I changed the face plate but that wouldn't impress the local linux users group... so I bought blue surface mount diodes and replaced the green ones. The thing about surface mount diodes is that if you heat them too much, they melt and lose their brightness. After the 18th one I was becomming quite the professional. When all was said and done, I marveled in the blue back light on my phone.

I had one customer who was going to throw away their laptop because it didn't work and needed a new motherboard to fix it. The customer was told this by multiple shops. I asked specifically what the problem was and they told me that the wireless stayed disabled no matter how the hardware switch was configured. Previous shops had ripped the notebook apart multiple times and replaced the wireless card and fiddled with the switch, charging several dollars each time. I asked to let me try and even though he was skeptical and fixed the issue in less then half an hour. Simply I identified the problem with the radio switch. Looked up the mini-pci express specifications and bypassed the radio disable circuitry on the wireless card by taping off and isolating the pin that controls the radio power down. I explained to my customer the implications; his radio disable switch does nothing and he shouldn't let anyone remove the radio card without noting the issue.

I had a friend who on Facebook was asking how to replace their ECU on their car. I asked her why she has the idea to replace the ECU on her car. Apparently, she reversed the jumper cables while boosting her car, and now would not start. She brought it to multiple garages which said she fried her ECU. This seemed pretty odd to me - I have a bit of an understanding of vehicle electronics so I offered help. I asked her what happens when she turns the key, to which she replied "nothing". I asked about the radio and headlights, which also did not turn on. At this point it was obvious that all electronic systems in her car were dead which means it must be something that has to do with all of the vehicles electronics. It was obvious that the previous garages who recommended her ECU be changed did not have an understanding of the problem or did not understand the vehicles electronic systems. The ECU does not control all systems. The ECU would be coded to the immobilizer in this vehicle, requiring reprogramming or tampering with the anti-theft system. Being a late 90's Acura, it isn't that complex of a vehicle and wiring diagrams are easily obtained. The ECU is designed to be robust, tolerating voltage spikes and drops that are typical and expected in automotive applications. In line to most systems are a few fuses and the ignition switch, but not the ECU. I told her to look under the hood for the master fuse box for the 80A battery fuse. A $8 fuse later, she was driving her car again.

A friend of mine had a Blackberry full of his businesses data. One day, several months after his last backup, the USB/charging port broke. He went to his cell phone provider which told him he is now SOL and there is no way to transfer the data off of his old phone and no way to fix it. I offered to help. First, I replaced the battery with a fresh one and then backed up his phone to my PC using Bluetooth. Restoring the data on to his new Blackberry his carrier convinced him to purchase. After, I used the lost art of soldering to replace the connector, making the old blackberry good as new. In this case, it seems the agents operating for the carrier were either ignorant of the phones features, unwilling to help, or insensitive to the importance of their clients data.

Another friend of mine owned a computer shop. One of his clients had bought an IBM laptop and accidentally set and forgot his BIOS password. My friend bought the laptop back from him and sold another. After he tried many passwords, I decided to take a shot at recovering the password... being a high-school co-op for a tech company that manufactured hardware, I asked for a few resistors and and capacitors to build a serial interface for an eeprom. They only had surface mount components, so I layed them out so that they were as close as possible and superglued them to a piece of paper, completing the circuit with solder and tiny pieces of wire. I re-assembled and powered the laptop on my desk with the interface attached and used another laptop to read the contents of the eeprom. The password was the guys first name.