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  1. Thanks Daniel, that area is not very clean, the cap leaked, as you can tell from the greenish around it. At this point I have IMO some options: - desolder it, clean it and put it back. I do not have special tools, I'm just good enough to solder SMD tantalum capacitor, it's probably behind my skills and I do not want to make practice on an Apple MB. - put it the dishwater for a couple of rounds Reading around, a mixture of water and acid citric (lemon) would help removing the conductive acid of the capacitor. Isopropyl alcohol does not help, it's good for removin
  2. can u please help me to locate the chip? I can not find schematics or a MB layout thanks
  3. interessing discussion guys. Since I am unable to get an. old enterprise switch I believe that the only way I have to network my Mac II is. to find a BNC router instead plus cables and terminators (I have another network card) or an AUI to RJ45 Ethernet adapter. Will I find other obstacles?
  4. thanks Daniel, cheesestraws for the reply. I tested the power supply: OK. 5V, 12V stable: OK I replaced the 3.3v battery: OK I recapped the mother board, please notice the replacement of the tiny capacitor (is it?) near C94 C95 C97. It came out and lost when cleaning, I replace with one of the same color from a scrapped device. Monitor connected I turned it on: black screen, classical chime and after about 1 sec i got the chime of death (car crash) I did several tests:
  5. If the Mac plays the crash crash sound after the startup bong can I assume at least the CPU is not compromise? thanks
  6. I replaced all the capacitors, the picture shows only three of them and the tiny capacitor I was somehow able to solder back (it was rescued from another device, same colour of the original that went lost ). I tested the continuity from each capacitor pin and the trace it's laid, everything looks fine, I checked the polarity numerous times. I assembled it back. Same checklist as above: it chimes as the fist but then I hear the nasty car crash sound, of course still a black screen. I tried with another pair of SIMM I had, known to be working, but with no luck. Ah, the h
  7. the tiny capacitor felt from here, see photo Is it mandatory to solder it back ?
  8. Hi pals, I just got a - externally looking - fine 6100. I tested the power supply: OK. I replaced the 3.3v battery: OK I looked for macroscopic leaking from the capacitors: OK the HD works fine, I connected it to another Mac: OK I turned it on: black screen, no BEEP 5V, 12V stable: OK reset PRAM quick on-off-on It turned it on: black screen, no BEEP, no HD activities I did then a closed inspection at the mother board, and I saw some sign of corrosion (see attached photos) close to some SM capacitors. It did not look so b
  9. Hi all, FYI I just moved a MB from a Mac Classic (Type A analog board), to a Mac Classic II unit (Type B analog board), it worked just fine. best Pierfranco
  10. Hi all, I have a faulty PSU in my mac classic, despite my attempts it still does not work I noticed that the AC-DC is isolated from the DC-DC part in the board, so do the CRT board downward. So, I have the crazy idea that by removing the transformer and the optoisolator, at this point I could inject the current from an external PSU into the pads where the voltages is supplied to the MB. Pls look at the picture. This could give power to the CRT and the MB. The DC DC it still connected but it would not, in my opinion, create problems. The question is: wo
  11. Hi Lyo, I am glad you fixed your problem, it does not matter the reason, you simply made it, so I assume you do not need the reading now. About my classi: while I was bench testing the PSU with the multimeter, I notices the voltage from 11,4 jumped steady to 12,2. So I gave it try and .. it worked, it is not hours that it is no, floppy, HD, SCSI2SD ... it does not restart anymore. Unfortunately I did nothing, so the problem might appear again in the future. About the DP3 and DP4 I checked them, they were just fine. Enjoy your Mac b
  12. Dear all, I'm stuck trying to repair the Analog Board of my Mac Classic (I have two of the actually). The issue with those boards is that the transformer and the CRT power section are in the same board. I'm not an expert, but in theory wouldn't be possible to identify in the schematics where the -12 +12 +5 GNR goes to the CRT part of the board to add instead the wires from a new PS? The same wires could be sent to the logic board and keep the V/H SYNC, VIDOUT, audio, brightness. I do not have the skills to face this project, but does this makes sent to
  13. Hi Iyo, I'm in your same situation, I know it does not help much at the moment but at least we can share some experience. I have partially resurrected a Mac Classic which was dead-silent, analog board code 820-0525-C. I replaced most of the capacitors, the TDA4605 (regulator), CNY17G (opto isolator), 79L12 (regulator), IRFBC40 (mosfet), 2 schottky diodes Now it starts up till the system 7 shows up, but shortly after it BEEPS and reboots showing an horizontal while stripe with a weird pattern. The 12V drops down to 10 ... This behaviour has to
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