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clh333

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  1. clh333

    SE/30 Floppy Issue

    The ROMINATOR II uses a flash-RAM - based image to boot, and so is using different logic-board circuitry than the floppy disks would. The fact that the machine boots from the RAM disk and not the floppies - especially given that you have substituted drives and cables - strongly suggests a problem with the logic board. Without knowing more about the sequence of events or any dialog boxes that may appear it's hard to say for sure, but there are some things you can check if you have a simple Ohmeter: According to Larrry Pina's Mac Classic and SE Repair and Upgrade Secrets, (Peachpit, c. 1993) P. 87-89, the problem may be related to a bad filter at board ref. RP10. This part is Bourns 4120R-601-250/201. The book describes the test procedure and gives a table of acceptable and unacceptable measurements. If you can't manage the tests yourself, perhaps the shop that did the recap work could do it for you. After all, they were supposed to test the board fully before sending it back to you, weren't they? Good luck! -CH-
  2. Thank you for your post and the tip about G 600056. I too have acquired the 68851 and will be adding it to the Prodigy board. I have already added the Prodigy utility software and accessed their control panel. I have not attempted to use the Connectix software since I believe -from what I read - it depends on the presence of a 68851. I guess I'll find out the hard way. The lack of RAM on the Prodigy board is the biggest limitation at the moment. When you refer to "the manual" are you referring to Prodigy SE User's Manual, P. 21, "Optional Features"? In my copy of the manual the text states: "When it becomes available, the 68851 will allow the Prodigy SE board to utilize RAM configurations of 8, 16 and 32 megabytes." At the time that was written (1987) apparently the 68851 was not yet released to the public. I don't know if any of the memory expansion boards were ever released, and if so in what capacity; I've never seen or heard of one. And I don't have any schematics, alas. But I wish you well with reverse engineering the memory expansion port. In my view that would be a great achievement. -CH-
  3. clh333

    Capacitor list for SE/30 analog board

    Thank you for the reference. I got right on it. -CH-
  4. clh333

    Mac SE CRT issue

    Later this morning I consulted the other Pina reference, Mac Classic & SE Repair and Upgrade Secrets which covers the same symptom but in greater depth, pp 52-57. Here he states that for the diodes CR2, CR3 and CR5 acceptable in circuit readings are in the range of 0 to 50 Ohms and bad readings are in the range of KOhms, which is what I got for CR2 and CR3. There is a transistor, Q2 (7 A 60 W, TO-220 case) that often fails along with these components. I will be ordering the parts and replacing all as a matter of course. I'll report back when I know more. Thanks to all who replied. -CH-
  5. clh333

    Mac SE CRT issue

    Thank you, Johnnya101, for your reply. " Could you have nicked it and unsealed it? Pretty sure those are the symptoms. " Meaning nicked the CRT while re-inserting the flyback lead? It's possible, but I thought the CRT implodes if the tube is breached. I checked both CR2 and CR3; each measured (in circuit) infinity in one polarity and about 4.3 K Ohms the other direction. I lifted the CRT board from the CRT pins and saw a small (neon?) bulb in the center of the socket. Apparently that's an over-voltage protection. The pins were shiny and untarnished. I put everything back together and tried power one more time, with the same result. I guess next I verify the components individually in other systems.
  6. clh333

    Mac SE CRT issue

    Working on a Mac SE (same as was referenced in PSU issue post earlier). After substituting a known-good PSU I assembled the computer and powered on, with the back shell removed for observation. Observed the following: No chime, black screen and a hissing, crackling sound. Immediately shut down. Checked all connections tight. Crackling seemed to have come from the rear of the chassis but needed a second brief power-up to locate the source: from inside the neck of the CRT; small arcs visible. Not good: I have no idea how serious this is or what can happen if it is allowed to recur but I assume this could fry something expensive. Referring to Pina's Dead Mac Scrolls, this condition is described on P 147 as an analog board problem, with shorted barrel-rectifier diode CR2 ( GI854, 600V 3A) the likely fault. While the unit was apart I refreshed the solder on the board; it's possible that I caused the breakdown of the diode. I can test this of course but other questions occur to me as well: In order to work on the analog board I disconnected the HT lead from the flyback to the CRT. When I reassembled I was careful to reseat it, but might I have missed something there; got it wrong? Also: in the course of disassembly I did not remove the CRT board from the CRT or inspect its pins for tarnish or signs of a poor connection. Should I have done that automatically? Could that contribute to this problem? I'm pretty sure the ground wire from the CRT board to the CRT chassis / frame is in the same position (upper left lug) and making good contact. Beyond that I'm not sure of anything. Any suggestions or help with diagnosis would be greatly appreciated. Thanks for your replies. -CH-
  7. clh333

    Sony CR44 power supply repair... or not?

    Thank you for the offer. Let's see if anyone else has any ideas. I'd really love to find that Sony chip or a replacement. Better yet I'd love to find out why the voltages are so far off. Thanks for your reply, -CH-
  8. Been reading http://www.ccadams.org/se/classicmac2.pdf and also Pina's books for info on repairing Mac SE power supplies. I have a Sony CR44 that tests the -12VDC lead as -8.5, +5VDC as 5.3 (both lines) and +12VDC as 13.5 and 14.2 respectively. I have already recapped the PSU and am reasonably confident the error is not the result of that work. However, that's as far as I went and now I suspect that the problem lies elsewhere. I have three choices, it seems: try further repairs on this unit; buy a (used) replacement or find a new supply to use instead. Each of these presents its own challenges. Pina is certain that IC 151, a Sony IK1H4, is at fault. I can't find that part anywhere and I have no cross-reference or data-sheet for the part. A used power supply may well have, or develop, the same problems this one has. A new power supply will probably need to be adapted for use in the Mac, and apparently not many supply two independent +12VDC supplies. I'd be happy to hear suggestions as to how to proceed. Thanks for your replies. -CH-
  9. I swapped the HD for one that had been initialized with OS 6.0.8. The machine booted to the Prodigy board and ran - faster, but stably. The System Index produced by the diagnostic utility says the board is 3.5 times the speed of a standard SE. Unfortunately there isn't a lot of RAM for other programs. I haven't added the Prodigy driver yet or experimented with Connectix software. Here are some picture of the board: in-chassis, on top of logic board, and close-up of chips and memory.
  10. Thank you for your suggestions. Yesterday I added the board to the SE logic board and fitted the sandwich back into the chassis. I was a little apprehensive as the Prodigy board, even with standoffs, sits right on the SIMMs and the other end is dangerously close to both the toroids and the chassis. But I got everything back in place and hit the power switch. I got the chime, a Prodigy SE splash below a smiling Mac with fangs, and then the message that OS 7.1 needed more memory to start. At that point I couldn't do anything other than shut down. The manual mentioned that the board always tries to take control on boot but can be defeated by holding the interrupt and pressing the restart buttons so I managed to recover control on the next boot. I could boot from a 6.0.8 floppy but then the Prodigy board could not assume control. I will either have to modify the board to add more memory - if I can find it - or revert to booting 6.0.8 from the HD. I haven't tried running Prodigy's proprietary software yet for obvious reasons. The Prodigy board has been wave-soldered; there are spare holes on the board for another 1 Mb of RAM but there are hundreds of holes that would have to be opened and then filled again to bring it into 7.1 spec. For now I'm just letting the board burn in; in a day or so I'll make up my mind how to handle the rest. Thanks again, -CH-
  11. I've used both and been grateful for their help. When I dug out the board I found the manual and an installation guide with it in the foil bag. The manual made mention of the software and my first thought was that I needed to find it somewhere. I checked the Garden and then the MR, where I found someone had posted the contents of the Rev C ROM but nothing more. Eventually I had the bright idea to look in my OEM floppy collection, where I found the Prodigy disk. Copying and posting the items was my way of saying "thanks" for others who have helped me. I don't do it very often and in this instance it was a pain in the @$$. But I'll be conscious of the prevailing winds next time. Thanks for your reply. -CH-
  12. Thank you for your reply. A copy of the software and user guide are now on Macintosh Repository. Presently I will add the board to the SE I just finished updating and see what happens. -CH-
  13. About a year ago I bought - on eBay - a Prodigy SE accelerator board, which I intended to plug into the processor expansion slot on my SE which has a SuperDrive. Not knowing much about compact Macs or anything about the board, I put it in a drawer for safekeeping until I was ready. Recently I finished going over the SE (memory upgrade from 1 Mb to 4 Mb, fresh battery, clean the drive etc.) and I thought about installing the Prodigy board. I dug out the board and the manual, which referred to a software utility disk. I looked on line for the utility but no one has a copy. So I checked around here and found that I have the disk, too. I don't want to screw this up: I haven't stuck the disk in any drive yet nor have I attached the Prodigy board to the SE. I'd appreciate some guidance on how to create a viable copy of the utility disk that others can reference and so that I have a backup of my own. Yes, I know about Apple's DiskCopy; the question is about creating something that can be uploaded and downloaded without corruption. Apparently the Prodigy board has its own RAM, one Mb from what I can see on this one, but can't use the SE's logic-board RAM without a helper application from Connectix. Again, new territory for me; any guidance in locating and installing the proper utility will be appreciated. Thanks for your replies. -CH-
  14. clh333

    Source for flyback transformer?

    From MacGUI I found an image of 7.1 as a set of 1.4 Mb disks. I created Installer1 on a DSHD 3.5 floppy with a G3 desktop and tried booting the SE/30 with that disk, to the same result. I verified the disk's viability by using it to boot another SE that had a superdrive and also verified my OS 6.0.8 disk with the same machine. So there appears to be another problem limiting my ability to boot. Additionally the video on the SE/30 has become unstable once again. Oh, well, back to the drawing board. Thanks again for your help. -CH-
  15. clh333

    Source for flyback transformer?

    I get a chime immediately on power-applied. I insert my boot disk and the machine spits it back out after a brief interval. After that I get a disk-with-question-mark icon and boot proceeds no further. I used this disk just the other day to initialize the HD of another SE I had been working on, and had booted yet another SE with it in the past. The HD is a 2 Gb Apple from IBM; the original Quantum that was on this machine was toast. The HD has been tested, verified and formatted on a Linux system but not initialized by an Apple OS yet. I have 68 Mb on the board: replaced all the original RAM with 4x16Mb SIMMs and 4x1Mb SIMMs with larger SIMMS in the first slots.
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