• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

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  1. J

    Repairs, on-board RAM and 475 / 575 boards

    Very nice :cool: Will you make a variant that can take a LTC1799 for overclocking? Like a built-in Spicy-o-Clock?
  2. J

    Repairs, on-board RAM and 475 / 575 boards

    Well that's fun :) Is this the near-conclusion of a recent project?
  3. J

    Repairs, on-board RAM and 475 / 575 boards

    The one I repaired most recently had some (impossible to visibly locate) broken traces between MEMCjr and the SIMM / on board RAM. The symptom for me was that it 'bonged' fine without a SIMM but did not boot, yet gave death chimes with the SIMM installed. After a lot of buzzing around with my...
  4. J

    "Power Macintosh Card" and "601 Processor Upgrade" - What is the difference?

    I've recently acquired an Apple 601 (50/66Mhz) card in a bombed 475. Does anyone have schematics for these? I'm probably going to have a go at overclocking a 575 and 475 with/without the upgrade card.
  5. J

    LC575 no screen crash chime

    My 575 boots fine without the on-board RAM, though I've only booted it from a BlueSCSI so far.
  6. J

    LC575 no screen crash chime

    Congratulations! Yes; the routing can be a pain. I have occasionally used needle probes to find a closer VIA or other piece of track that is more convenient (with the usual faff of trying to solder it).
  7. J

    LC575 no screen crash chime

    Have you checked the data and address lines to the SIMM? I’ve had 2 boards where some of these were corroded out. The signals are shared with the on board RAM so just removing that won’t necessarily help. The 475 I just ‘fixed’ had some traces broken on the address lines both between the SIMM...
  8. J

    Repairs, on-board RAM and 475 / 575 boards

    I have now 'repaired' two boards (one each of a 475 and a 575) where some/much of the data/and/or/address lines under the on-board RAM have been destroyed. In both cases, I've been able to get enough bodge wires in place to be able to get the boards booting without the on-board RAM (just enough...
  9. J

    Can this 575 logic board be saved?

    Hi Terry, sure. I've cleaned up my notes and included them below. Apologies for the random way I did the pin counting.
  10. J

    Bombed SE/30: Is it dead, Jim?

    Sorry, the boards hadn't fully dried out from the IPA when I took those.
  11. J

    Bombed SE/30: Is it dead, Jim?

    Thanks for the input, folks. This is the board after 1 round of vinegar, soap + IPA. There's still all lot of battery muck underneath the '030 and a few other chips. I'll have a go at desoldering the '030 to clean up underneath but, given the corrosion through some of the holes / along the...
  12. J

    Bombed SE/30: Is it dead, Jim?

    Thanks for the input, folks. I'll see what it looks like with the muck cleaned off but I'm not hopeful. I've still got a fair amount of IPA etc from bringing two Classics (I and II) back to life. As for the rest of the SE/30; I'm wondering about holding out for a working LB versus attempting...
  13. J

    Bombed SE/30: Is it dead, Jim?

    I recently acquired a known dead SE/30 (my first such machine) and, as expected, the battery has done a thorough job on the logic board. Usual suspects, from what I can tell: Rotted out VIAs, some of the '030 pins have been corroded through the board and who knows what else. And, oh yes, very...
  14. J

    3D-Printed Objects

    That’s the one!
  15. J

    3D-Printed Objects

    Hi Folks, As part of a conversation with @JDW, I'm uploading a 'tabless' version of this speaker case. The reason being that, if you printed a tabbed version for the CC stereo mod, the tab crosses into the larger area of the original CC speaker and makes it hard to fit everything together. This...
  16. J

    Mystery PCI card in a PM7500

    Thanks everyone! I had googled the PCB numbers but didn't come up with any obvious hits. I'll do the research (y)
  17. J

    Mystery PCI card in a PM7500

    Does anyone have any idea what this might be? Looks like a DB62 and has a PCI Vendor of $1203, Device: $1. The Vendor ID maps to "Bayer Corporation, Agfa Division" in online databases… The machine it came in also had an ethernet PCI card, but no hard drive (so no clue from potential drivers...
  18. J

    3D-Printed Objects

    I decided to try the Color Classic stereo mod, but didn't have anything I'd want to cannibalise for a second speaker. So: I modelled one based off of the original in OpenSCAD. This version matches the orientation of the original but has holes for self-tapping screws to hold the speaker in...
  19. J

    Introducing (and interest check) AirTalk: Wireless plug-and-play LocalTalk dongles

    I’d be interested in two please. Thanks!
  20. J

    Color Classic VGA Mod. the CORRECT way

    Part arrived and all looks good. I'm not quite at 84V and the CL26 capacitors just seem to make the display dimmer and more wonky. I've still got fairly thick horizontal borders that I'd like to remove. What test points do you use to measure the horizontal scan voltage? I've been measuring it...
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