Date: Fri, 27 Oct 1995 11:29:40 -0700 From: Tidal Bass Generator Subject: How to Fix Your... (Re: PPG probs) At 10:27 AM 10/28/95, D.A.C. Crowell wrote: >And BTW, no, I haven't >"popped the hood" on it yet to check for unseated chips or such; I'd >prefer to find out from some other owners first as to whether the Wave >2.3 has a tendency to unseat chips or do other simple weirdnesses before >digging into it. If it has any socketed chips and it's been turned on/off regularly, then it will have a tendency to unseat chips. If they're cheap sockets, they'll unseat sooner than later. I once had an AppleII+ that became totally unuseable due to power cycling causing the ultra-cheap sockets to fail due to thermal expansion/contraction. When pushing down on the chips no longer worked, I put in quality machine tool sockets and that cured its ills. Another reason to leave your equipment turned on... >It's not like we're dealing with something like my Pro-One here... But the basic approach to fixing them is the same. Here's how I fix 70-80% of my broken gear (and no, it doesn't require an Electrical Engineering degree). 1) Unplug the machine, open the case, ground yourself, and take your thumb & press down on all the socketed chips. Also, make sure all connectors and daughterboards are seated snugly. This should fix it 40-50% of the time. 2) Check the fuses. If one is bad, replace it w/ an IDENTICAL REPLACEMENT. DO NOT USE A BIGGER FUSE - THIS IS ASKING FOR BIGGER TROUBLE THAN YOU"VE ALREADY GOT. If there's no problem w/ the fuses, take a Voltmeter, & w/ the synth turned on, carefully check the power supply Voltages. If one of them isn't right, then it's probably the Voltage regulator. At this point you need to find out more about the power supply, how to locate the Voltage regulator(s), and identify the input & outputs. Once you learn what a power supply is supposed to look like, this is pretty easy. Fixes maybe 20% of problems. 3) Look for smoked parts. Occasionally you'll see one that's discolored, melted, or w/ a chunk blown off. Replace it. 5% solution. 4) Look for battery acid. If found, clean up w/ alcohol, replace the battery, & look for circuit traces that have been eaten. If they have been, you have to bridge the missing traces w/ solder and wire. Not for the faint-hearted. 5% 5) Look for broken circuit boards. All the traces must be bridged across the break. Attempt only if you're a good solderer. I had to do this w/ a D50 once, w/ REALLY fine circuit traces. What a nightmare. Again, 5%. If none of those fix it, then you probably want to go to an electronics technician, preferably one who works on synths (though it's hard to find one who also knows digital, which is going to be important in this case). I suspect your problem is in the CPU and/or RAM - something is causing it to go out to lunch & execute garbage. Good luck. 808 But analogue synths are like pizza. Even BAD pizza is GOOD pizza. - Matt Haines