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Message body Emoticons View more Emoticons	Font colour: Default Dark Red Red Orange Brown Yellow Green Olive Cyan Blue Dark Blue Indigo Violet White Black  Font size: Tiny Small Normal Large Huge Close Tags [quote="Anonymous"]Hello everyone, Recently, I cheaply acquired a rebadged Mustek R100A DVD Recorder at auction, well aware of the risk. After lubricating a seized component inside the drive, the unit began working reliably (which is rare, search Google for this model to read horror stories) for a few days. Soon though, the unit began locking up, started taking longer to "boot up", would refuse to open the tray and fail to properly burn programs. I traced the problem to high voltages coming from the power supply which eventually dropped after it (over?)heated up. Once the voltages dropped a little, the unit began to respond again. The power supply is a Fairway VA3523 - A Rev 1.0. Interestingly, this very forum has a thread "-27volts from a PC power supply" about the subject, and a search on Google for "Fairway VA3523" turns up more. The -27v rail supplies 31.6v when cold and 31v when hot, -12v is 15.3v cold and 14.8v hot, +5v is 4.1v cold and 4.4v hot and the 3.3v rail stays at 3.1. The unit uses a single opto-isolator for the feedback. Most of the large filter capacitors on the secondary side show bulging and run quite hot. Normally I would simply replace these, but I am still not convinced their damaged condition is the cause of the poor voltage regulation, rather the effect. In other words, I suspect they may have been damaged by another problem. I am convinced; the high failure rate of these DVD recorders is because of the power supply. This brings me to my question: Do you know of a certain weakness or the cause of the power supply failures so I can correct them directly? I am a student and just don't have the time anymore for normal troubleshooting. Normally I would replace the opto-isolator and capacitors then continue with further tests, but I just can't afford to waste time and energy on false leads right now. Also, I am tempted to replace the capacitors with ones of similar (but not exact) capacitance from some PC PSUs I have lying around as I need to travel for 4-5 hours to buy new replacements. What is your experience with this? The capacitance is around 20% either way from the original. Thank you in advance for any advice.[/quote]
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