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Showing results for tags 'flyback'.
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Nathanplus posted a topic in Compact MacSo I'm starting a new topic to update my old one. Check out the whole story on my original issue. After finally getting a new fly back for my mac plus the fast ticking never changed. I checked the voltages on the caps and sure enough the flyback still is not getting enough power. So what I did was first heat up the caps to see if any of the 33 and 22uf caps are bad. They didn't change any thing other than speed up the ticking a little. I have never got it to stop ticking while using the heatgun. Then I thought it was my motherboard so I drowned it in vinegar carefully using an exact-o knife on corrosion and blew under neath every chip on the board to get crud out. This obviously it didn't do anything. Also during all that I cleaned the cable and tried the voltage pot, to see if the voltage was too much or too little. Nothing changed can someone point me in the right direction I'm still at a dead end.
Hello people! I recently acquired a Mac Plus while doing a clean out of my grandfather's old factory. The keyboard and mouse were FUBAR, as they had been left under an old can of paint which leaked all over them. He said that there was also a hard drive somewhere, but we couldn't find it. I scrubbed as much old paint of this Mac as I could, and besides from a rather even coat of yellowing, it seems to be in pretty good nick. I took it home and plugged it in, and it made the start up bong and the floppy drive made noises, but the screen never fired up. I cracked open the case and besides some dust, everything seemed to be in relatively good shape. No caps were leaking, and nothing looked corroded. I also discovered that this Mac had 4Mb of RAM. Nice! I came to the realisation that this Mac had deeper problems. I noticed when I found the Mac, that it had LOTS of screen burning, which indicated to me that the CRT as a whole could have just bit the dust, or that the flyback transformer was completely screwed. Further poking around inside the machine also revealed that the CRT power connector looked like it was burned or melted. I thought while I had it open, I'd perform the cap change just in case, for longevity if I ever got this thing working. I couldn't find all the correct caps, so I used some higher volt ones, and there was one blue non-polar one that I didn't change at all. Upon firing this up after the change, it worked! I have no idea why the cap change fixed it, non of the caps seemed damaged in the slightest, I verified this when I removed them. No residue or anything! So now I have a semi working Mac, but I have 2 issues which I'm unsure of how to fix. The computer makes a REALLY REALLY high pitched squealing noise. I think this may be the flyback transformer, but I'm not sure. UPDATE: When I fired up the machine to take the photos in this post, the noise was gone! I'm unsure if it will come back, has anyone else had this problem? It's also VERY hard to insert floppies into the drive. The seem to be stuck on something, I'm not sure what though (I've made sure it's aligned correctly). Also, sometimes when I put them in, the jitter around in my hand like crazy until whatever mechanism in there stops, and I can finally insert the disk! And on top of that, the auto eject doesn't seem to be working, but I'm not that familiar with macs that boot directly from disk, as my other mac (a mac classic) is currently not working AND it has a hard drive. I also have no boot disk to test this machine further. Let me know what you guys think!
Hi Everyone, I recently acquired a Mac Plus with a temperamental analog board which would only display a picture briefly whilst being tapped on the left side. I tracked this problem to a failing flyback which I have replaced, but I now get horizontal scan lines across the display which I cannot get rid of (whilst also maintaining the video brightness) by adjusting the brightness knobs. The Mac itself is otherwise working I've tried replacing R5 but to no avail. Any suggestions? Thanks