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buserror

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    UK: Berks,Bucks & Mid Wales

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  1. buserror

    Broken Macintosh II Repair

    I'm currently doing the same job, and I decided outright to change UB1 and UB2 -- make sure ALL the traces connect while the chips are off the board, as on my board, some of the traces between UB1&2 were corroded enough to remove connection between pads. Also check on the power button side, as there was quite a bit of damage there, I decided to change the SCC ICs there as well as they were badly corroded. I've been fixing another problem with another piece of kit so I ahven't had time to power mine up yet, but I hope I can do that in the next few days!
  2. buserror

    Mac II refurbishment..

    Anyway, project still ongoing, as I had quite a few other thing to do recently. However today I did 'recap' the whole board, and I just have to re-install the SOIC14 x4, then add a couple more wires (for failed traces on the pads there). I only have one worrying trace I can't do anything about unless I remove one of the 10000 pins big IC, and I won't do it unless it fails to start! I checked under the SIMMS, under the ROMs and well everywhere I could, and I hope its now acidicaly 'stable'. Also, I took the PSU appart and it genuinely look pristine, the caps have not leaked, not bulged, and it looks splendid so I think I won't recap that for now. Couldn't see a RIFA either Anyway I think tomorrow is SOIC day, and tests. Wish me luck!
  3. buserror

    Mac II refurbishment..

    Ok so today I did another run at the Mac II, discovered a couple of extra traces that were cut (some are quite subtle!!) near the power switch. I ended up cleaning the thru hole cap holes with the tiniest drill bits and that was a lot less stressfull than all the other attempts and methods I tried. I don't know what I'm doign wrong, but no amount of heat. So I've now reinstalled the big caps, and the battery holders. I still need to do another inspection, then wil be re-solderring the SOIC14's, then I have a couple of extra patches to add for traces that are cut /under/ these SOIC footprints, (I don't put the patch wires now as I'm going to put hot air in the area). So I'm getting there. I had a close inspection in the RAM slots and it all look clean. My worries are the areas near the Sound Chip and the GLU, and I can see a couple of traces that look 'dark' go /under/ the ICs One thing: I've heard you can put the mobo thru the dishwasher to clean all the rest of the gunk that is under bits and connectors. Does anyone has done this? ie short cycle, no soap, low temperature than air compressor, then let it dry for a week, or bake it?
  4. buserror

    Trick to desolder thru holes?

    Where's the +1 button around here Thanks @Michael_b and @blusnowkitty
  5. buserror

    Trick to desolder thru holes?

    Ah good tip, in fact, excellent idea! I also have hot air so I'll try that next. I've been sulking for a day or so because of that problem so it gives me "options"
  6. buserror

    Mac II refurbishment..

    I got 2 of 3 of these, I even have the 'heated tip' one... doesn't help much. I think I'll have to try the "iron heating one side of the board, pump on the oher side" and see if that helps..
  7. buserror

    Mac II refurbishment..

    Ahaha, I'm an expat. I worked for Apple ER&D in the 90's on the Djinn and Apple Telecom 3.0 (and a few other bits) -- but I moved to the UK in '99 ! So you were both right @joshc yes I picked that machine in the UK near Ash, I'm near Maidenhead myself. Thanks for the tip on desoldering station... I'm a bit reluctant as I normally don't need to do that sort of things, especialy these days of SMT where I have all the gear already. Do you have one? any suggestions?
  8. buserror

    Mac II refurbishment..

    Yep, that's the one! Well ahead of it's time, as apple was, at the time...
  9. buserror

    Trick to desolder thru holes?

    Thanks, I do try all of these, add solder, add flux, use 400C on the iron etc etc not much luck. Well i cleared about 2/3 of them using various combination of these, but some are just... tough!
  10. buserror

    Mac II refurbishment..

    Some more work today, cleaned all the caps locations; added 3 new wires, the worse being around the cap near the Apple Sound Chip, there's 3 traces there WAY close to the cap, and these got damaged. Only one needed a wire tho. I also saw a couple of traces that look 'dark' but one diseapear under a SIMM slot, and the other one of the niggest QTFP at the bottom of the board. Oh well, I'll have to cross my fingers and hope they still do the job, because I don't see myself reworking that huge chunk! Now a bit stuck trying to clear the holes of the thru-hole caps (posted another topic about that) and I'm nearly where I'll be able to solder all the new bits on! I'm really taking my time here, scrapping a few vias etc to remove corrosion, etc.
  11. I've desoldered my thru hole caps, but the hole is now 'full' and no amount of heat and manual desoldering pump seems to help. Do I have to re-drill the center with one of these tiny bits? Seems some of the holes are straight onto a power plane, so they act as heatsink...
  12. buserror

    Mac II refurbishment..

    Well, so work has started; I got all the parts, removed all caps, removed the UB1/2 and the SCC drivers started cleaning the joins, scraping the vias and looking for corroded traces. Already repaired one near the ROM, where one of the long tracks near the C7 label looked corrored, so I scapped some on each side, tested continuity and sure enough, no go. I soldered a new tiny enamel wire there (it's barely visible!) and superglued it, good contact now. I found another one near UB1 that should be easy to repair once I've put the SOIC14 in place. I've been using some sort of "glass fiber pen" to scrape a few contacts, works great. BTW, the enamel wire in the pic is THE famous R3<->R18 trace -- the resistors are under the board, but the trace comes back up and here it is! So it seems the acid is particularly active to traces that are under (even minuscule) power, as that's the only one that is that badly damaged. Same toward the power button; one trace out of the blue while all the others are OK.
  13. buserror

    RaSCSI Development Thread

    So does anyone have made one of these? do they work? I really like the fact the SD card isn't a 'special' format so I can copy/backup disk images from/on it...
  14. buserror

    Mac II refurbishment..

    I was pondering that actually, but, I couldn't find a coin cell holder that would 'look' nice in the place in question. If you have any suggestions I'd go for that as (like everyone) I don't trust these 1/2AAs -- never did, they used to fail even back in the days! Also, any suggestions on what else to replace since I'm there and desoldering bits? Also... any suggestions on how to clean the damage? To be fair it's pretty 'light' by the standard I've seen. There's a trace under Nubus 4 (or 5) that took a hit, but it looks like thick copper and continuity seems OK. There are a couple of other traces that are a bit more problematic, whith what looks like corrosion /under/ the mask. Should I strip these and re-lay some solder? Should I leave it alone?
  15. Hi Everyone, first post here. I used to be a Mac developer, between maybe 1986 until 2007. I still have a large collection of machines, and some prototypes, and I've been making myself a small museum in a spare bedroom, quite frankly really Apple II stuff. But then I manage to find a Mac II, completely pristine, with 13 Trinitron etc for a song, and I bought it. Now I'm in the 'rabbit hole' as you must realize I never had a Mac II, I worked on some of the series, but never 'owned' one. I have quite a few powerbooks, 140, 180, 180 165c, 230. 280c and even a 180 with a wireless modem in place of the floppy disk! (one of 2 prototypes) -- but mostly in these days, I only owned a powerbook in my name... Anyway, the good news is that quit being a Mac dev to go more toward hardare/firmware/linux things, so I got quite a few tools to rework bits and stuff, thats something I wouldn't have been able to do all the way back then! Since trying to start the mac (and failing) I discovered pretty much all there is 'wrong' with these machines. The 2 batteries (holders on order now) and all the caps (ordered) the corroded traces and the 4xNAND gates, and the other bits I noticed I could change. I've just joined so I can document this here, as I picked a few threads that helped a lot understanding what's going on with this machine!
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