Recent content by Mark_W

  1. M

    Fix old Quantum drives

    Just to add my 2 cents, I managed to fix a few conner and quantum drives with melted rubber bumper on the magnet, just wrap a few layers of Kapton tape around them and that's it. Tried to clean the goo once but made a huge mess, so never gonna try that again... For those quantum drives with...
  2. M

    Sound issue recapped SE/30

    Have you tried the headphone output? Is the sound clear on both channels? If so the opamp that drives the internal speaker or the speaker itself might be faulty. If only one channel is clear then one of the sony sound chips isn't working, otherwise either both sony chips or ASC at UE10 is...
  3. M

    Color Classic analog board re-design, needs community feedback.

    Should be easy to add a few extra pads and use jumper wires to reconfigure secondary winding connections to achieve 60V, 68V and 84V +B. Sense lines can also be made reconfigurable with jumpers. Also on HDMI output, the main issue with those cheap VGA-HDMI adapters is they only accept 31KHz...
  4. M

    Weird Classic Woes - RAM or Logic Board?

    Try to remove the ram expansion board and boot with 1MB onboard ram only, then run a memory test with snooper, see if it reports any error, although from my experience ram failure is always reported on boot up.
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    Color Classic analog board re-design, needs community feedback.

    Good job. In your schematic you marked DL1 as BZX84-C8V2 which is a 8.2V zener diode. I also checked the schematic made by @jonschultz which marked DL1 as BZX84-B36, a 36V zener diode. Which one did you use to get it working? Also seems XC1186B does have xray protection, DL3 is fed by a sensing...
  6. M

    Color Classic analog board re-design, needs community feedback.

    That's normal, unlike main power supply that has feedback control on the secondary, ctr power supply is regulated only on the primary side, it will fluctuate quite a bit as load changes. IIRC on standby +B is about 70-80V, so your reading is ok. Don't think xc1186b has x-ray or +B protection...
  7. M

    Color Classic analog board re-design, needs community feedback.

    If HOT is not shorted and CRT PSU does not enter protection mode after it tried to start initially, then the fault might not be in the horizontal output stage. Did you check the main power supply and see if it works well under load? And +5V standby voltage? Also check POWER_SAVER signal coming...
  8. M

    Mac SE - sad Mac

    Did you check your ram sticks in another mac? Or put known good rams in it? Pretty sure it's a ram issue, I had an se showing the exact screen (sad mac with alternating texts) due to a bad ram stick. Apparently ram chips can go bad after sitting in storage for a long time. Sockets can also...
  9. M

    Color Classic Resolution Switching

    Nope, without adjustment the picture is slightly compressed horizontally, vertical size remains the same. Makes sense as vertical/horizontal size is set to 512x384. To adjust aspect ratio to 560x384 I have to shrink vertical size since horizontal size is already at its maximum, so I will end up...
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    Color Classic Resolution Switching

    I do have a 520 logic board installed in a cc chassis, and I can confirm you can switch resolution to 560x384 in monitor settings: And switching to 560x384 does work, the screen shifts a bit to the left and compresses horizontally. However, the first time I tried to switch to 560x384 crashed...
  11. M

    SE/30 Reloaded no sound

    I think those are jumper pads to bypass headphone detection in the 3.5mm jack: If you short them sound should be routed to the opamp for speaker output even a headphone is plugged in. Do you have sound from headphone jack? If so double check the opamp circuit, also clean the headphone jack...
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    SE/30 logic board pad question

    I wouldn't recommend using hot air station to remove those caps. The type with yellow plastic wrapped on them will explode when exposed to heat, when they don't violently explode the rubber seal would expand out and make a mess. The other type with ratings printed on top is usually more...
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    Macintosh SE FDHD/SuperDrive Slow Booting with Checkerboard Pattern

    Hi all, thanks so much for your input. I double checked the voltage, reseated both rom chips as well as the swim chip, problem persisted. Swapped the motherboard into an SE chassis, same issue. Then I noticed something, I put a 47uf capacitor on C36 by mistake: Which should have been a 1uf...
  14. M

    Macintosh SE FDHD/SuperDrive Slow Booting with Checkerboard Pattern

    Hello all, I picked up an SE SuperDrive last week and been busy restoring it. Cleaned the floppy drive and replaced the eject gear, recapped the analog/logic board and the power supply (it has an astec power supply and all capacitors tested good, but replaced them anyway), also dealt with...
  15. M

    MacSD inside a Mac Color Classic 'Mystic' - possible?

    Never used macsd before, did a quick google search and found this picture on their website: If the scsi connector is placed at the middle of the pcb then no it won't fit in the cc, cc's scsi cable is quite short and is connected to the motherboard edge connector directly so you can't replace...