I've been getting more handy with a soldering iron lately, and I feel confident enough to start performing basic repairs and mods for consoles. Here's a list of what I can do:
*Atari 2600 voltage regulator replacement
*Atari 5200 power mod (for 4-port consoles only, lets you plug the power supply straight into the console)
*Atari 5200 S-video mod
*Atari 1200XL chroma fix (restores S-video and improves video quality through composite)
*AV Famicom controller port fix (lets you use the Zapper and other NES peripherals on the AV Famicom)
*Colecovision AV mod (S-video and component not offered at this time)
*Commodore 64 S-video mod (lets you use standard S-video and RCA cables)
*NES external audio mod (for use with the PowerPak, Famicom carts with audio chips, and the Famicom Disk System)
*NES lockout chip disable
*NES connector replacement/repair
*Game Gear cap replacement
*Genesis region switches (model 1 only)
*Genesis S-video mod (model 1 only)
*Neo-Geo AES S-video mod
*N64 cart slot trimming (for Japanese games)
*PSP screen replacement (PSP 1000 only at this time)
*Sega CD fuse replacement
*SMS 50/60 Hz switch (model 1 only)
*SMS S-video mod
*SNES cart slot trimming (for Japanese games)
*TurboDuo cap replacement
*TurboExpress cap replacement
*VIC-20 AV mod (lets you use standard RCA cables)
If you want any of these done for cheap, send me a PM and we'll work something out. Here's some examples of my work:
http://www.youtube.com/watch?v=n-bIckT-Grwp
http://www.youtube.com/watch?v=fkqpAKwv1EA