A while ago I bought a Macintosh 512Ke in its original box. It was described by the seller as tested and in good condition, and a photo of the working unit was shown in the auction. After paying the money I anxiously awaited my new purchase, looking forward to the excitement of starting up this piece of computing history.
Naturally the Spectrum was the best computer ever, because it was just like the ZX81, only with some colours, and a noise, and it was surprisingly cheap for all that. Even the keyboard was better, feeling like recently deceased flesh instead of the fossilised flesh of million year old dead plastic dinosours.
But then again the Commodore 64 really amped things up with its 16 shades of brown and properly arcade quality synthesizer, even though the BASIC couldn’t actually do anything and the floppy drive was slower than a three legged rocking horse.
I started to disassemble a bread bin C64 for diagnosis. It was sold as "Used to go about 12 months ago, now doesn't" and the PSU was pictured in the auction but "sold separately". The case looked to be in reasonable condition in the picture so I thought it worth the risk at $15NZD (about $10 USD). Upon receiving the unit I noticed the power LED negative wire was obscuring the power socket. The seller must have had a fiddle after finding out it didn't go. Chances are the PSU will now blow up someone else's C64.
This unit gives no sign of life when power is applied, and the power LED does not light. Upon removing the top cover and cardboard shield I found signs that repair has been attempted at some point - possibly successfully. A capacitor and VR1 - a 7812 12V regulator - have been replaced, and the solder job doesn't look too professional. The power socket feels very loose to next steps will be testing that power is making its way to the board, and testing the VRs. That's as far as I got this evening.
UPDATE: Looking at the schematics, the LED connector (the sixth photo below) is cunningly designed to work either way 'round! Very nice touch.