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AwkwardPotato

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Everything posted by AwkwardPotato

  1. AwkwardPotato

    Macintosh Classic II Restoration

    Personally I'd just use a soft brush to clean the dust off the high-voltage parts (I don't feel too comfortable getting water, etc. near them). Really look forward to seeing your progress on this Mac; your previous restoration threads have been really cool to watch!
  2. AwkwardPotato

    Help revive an Original Macintosh Prototype

    "X2" basically is the voltage rating, so you can just look up "x2 capacitor," choose "Safety Capacitors," and then pick the options "Radial" and "Safety Film Capacitors." Pick a part with the same capacitance (measured in F, farads) as the damaged one (should be written somewhere on the cap), and make sure to get one with leads spaced roughly the same width as the one in the Plus. I'd also check the datasheet for the part you find just to make sure it is an X2-rated part.
  3. AwkwardPotato

    Help revive an Original Macintosh Prototype

    You can probably remove the filter cap for testing, but definitely plan on replacing it. Replacements for these can be found on mouser.com or other electronics distributors. One thing to keep in mind: there are two different kinds of line filter caps in Compact Macs: X2 and Y2, and you need to replace like for like; e.g. can't replace an X2 with a Y2. They should be marked on the top/side with what type they are. Yes, definitely discharge the CRT before doing any work on the analog board.
  4. AwkwardPotato

    Help revive an Original Macintosh Prototype

    For starters, resoldering the joints on the flyback transformer and all of the connectors might help.
  5. AwkwardPotato

    Help revive an Original Macintosh Prototype

    C33, C37, and C38 all appear to be RIFA line filter capacitors, and those don't affect the operation of the computer when they fail.
  6. AwkwardPotato

    ABD Keyboard and Mouse Options?

    Found it here. Admittedly being a wiki it could definitely be wrong, although I've always found this one to be pretty accurate (bit of a keyboard enthusiast myself). Do you have a serial number/date of manufacture for your keyboard? Given the madness that was usually going on at Apple around that time, I wouldn't be too surprised if they did in fact release the AKII before 1990
  7. AwkwardPotato

    ABD Keyboard and Mouse Options?

    A bit of googling about reveals that the original Apple Keyboard/Extended Keyboard (M0115/0116) were released in 1987 to match the Mac II and SE, and the Keyboard II was released in 1990 to match the LC.
  8. AwkwardPotato

    LCII crapped the bed

    I can confirm the EGRET causing issues too; on the LC series they usually sit in a nest of caps and all the leads get corroded. I've been able to get an LC II to go from a black screen to a '?' floppy screen by reflowing the leads before.
  9. AwkwardPotato

    Macintosh Color Classic No Sound After Recap

    It could be the TDA7052A itself that's faulty.
  10. AwkwardPotato

    Macintosh IICX No Video After Recap

    Sometimes SEs and SE/30s (with which the IIcx is closely related) have the issue you describe when the Bourns filters go bad. The IIcx doesn't seem to have the same kind of filter found in the SE/30, although it does have one at RP13 right next to the external floppy port. Maybe that part is causing issues?
  11. AwkwardPotato

    Macintosh IICX No Video After Recap

    That plastic bar isn't stock. It's hard to tell, but it seems that the tabs for some of the SIMM slots have been snapped off, so I'd guess the bar is there to hold the SIMMs in place (and maybe the RAM not being seated correctly because of this is part of the problem).
  12. AwkwardPotato

    Macintosh IICX No Video After Recap

    Check for continuity between C2 and R3, and between R3 and the internal speaker jack. Run patch wires between them if there isn't continuity to fix the sound issue. As for the chimes of death, a good starting point would be to make sure your RAM is good, if possible.
  13. I think the 6360 and 6400 are also Alchemy-based.
  14. AwkwardPotato

    Macintosh Color Classic No Sound After Recap

    Following the traces is probably your best bet since there isn't an analog board schematic to show what's connected where. TDA7052A could possibly be at fault too, it's hard to tell for sure. Just wondering, what are the voltages at pins 1 and 4 of the TDA7052A (not sure what exactly they're supposed to be but it may help)? Also, can you upload a picture of the top and bottom sides of the board around where the TDA7052A is so we can see if anything is obviously damaged?
  15. AwkwardPotato

    Macintosh IICX No Video After Recap

    Not sure about this, but wouldn't you at least get a chime of some sort regardless of if the NuBus controller is good? Are all the voltages from the power supply good?
  16. AwkwardPotato

    Macintosh Color Classic No Sound After Recap

    I'm not very familiar with the Color Classic, but I'm fairly certain amplification is done on the analog board since there's an amplifier IC (TDA7052A) next to where (I believe) the speaker connects.
  17. AwkwardPotato

    Macintosh Color Classic No Sound After Recap

    Probably an issue with the amplifier then, which as far as I can tell is on the analog board. Have you recapped the analog board yet?
  18. AwkwardPotato

    PowerMac 8500 AV Card

    I was recently able to buy my dream PCI PowerMac, the 8500! It works great, although I can't for the life of me figure out how to use the AV Capture Card. My first question: Is the television connected to the composite video output supposed to mirror the monitor attached to the Mac's DB-15 port? Second question: For some reason, instead of starting, Apple Video Player says that the Video Startup 1.7.3 extension needs to be installed and the computer needs to have video capture hardware (both of which are true for this machine). I feel like both of these issues are occurring because I'm missing an extension/driver/etc. although I'm not sure. I'll note that the only changes I've made with this so far are doing a clean install of System 7.5.3 & upgrading Apple Video Player and the Video Startup extension to 1.7.3 (stock Player version bombed while starting). Also, my primary monitor is running at 1024x768 @ 75hz. Thanks!
  19. AwkwardPotato

    Macintosh Color Classic No Sound After Recap

    Have you tried plugging some headphones/powered speakers into the computer and seeing if the sound from them is audible?
  20. AwkwardPotato

    IIsi death chimes after re-cap and then worse

    No problem EDIT: One more thing I should mention is that when the oscillator is installed, make sure the oscillator's metal shell isn't touching the wire.
  21. AwkwardPotato

    IIsi death chimes after re-cap and then worse

    It's hard to tell but I'm not sure those two vias are the ones connected by that trace. I'd use an x-acto knife or something similar to scrape away the soldermask covering the trace, clean with IPA, tin the trace, and solder a wire on each side to jump over the cut. Don't worry about making it look perfect, it'll work just so long as there's a connection. By the way, it seems that the severed trace is also part of the CPU's data bus, which would explain why it's not working correctly.
  22. AwkwardPotato

    IIsi death chimes after re-cap and then worse

    That may actually be the problem: Trace on the bottom is severed, and the two on the top are suspect.
  23. AwkwardPotato

    IIsi death chimes after re-cap and then worse

    Hmm. You mentioned that you broke a leg off the old oscillator; I wonder if it's possible the through-hole for it was damaged too, resulting in loss of the clock signal to some components (unless it was broken off after it was removed from the board in which case disregard this)? Also wondering if given that it worked before recapping, there were traces damaged while it was being worked on, hence causing it to have this issue after recapping. Close-up pictures of the areas around the replaced capacitors might help with spotting such damaged traces.
  24. AwkwardPotato

    IIsi death chimes after re-cap and then worse

    Do you have the original oscillator available to swap in and rule that out as an issue? Pictures of the top & bottom of board might also be helpful for identifying any mistakes.
  25. AwkwardPotato

    SE Dual 800k - Issues with Lower Drive Port

    Sure, that would work fine too; it would be the same electrically.
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