I've stolen the best computer repair guy (in fact anything repair guy and anything to do with computers!) from the capital - sorry, he's here in the UK now (might bring him back one day). I'll ask him tonight if he knows anyone and if you're not sorted I'll let you know tomorrow.
Actually, I have been told Mac computers are built to last three years after which parts start failing. By the way, I am a faithful Mac user. The explanation is that in three years the technology has changed in such a way, that one is better off replacing the whole machine.
I've had two macs repaired here. The DR seems to be extra hard on electronics. My relatively new MacBook Pro was sent out to the central authorized Mac repair via the RADIO SHACK in the Bella Vista Mall in the Cap. The charge 500 pesos to clean and diagnose but the rest was under warantee. My older one --a G4--has been worked on by CompuHelp in Gazcue Plaza. Let me know if you need numbers for these people.