68kMLA Classic Interface
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| Yet another portable start up issue | |
| Posted by: timoog on 2022-05-12 09:30:00 Hi all, been doing some work to resurrect the portable but only getting as far as the flashing ? disk. Non backlit, standard power supply putting out 7.52v, I've recapped the board washed and dried (not oven baked tho) New lead acid battery and fresh 9v. The hard disk was trashed sticky and making horrible noises so will go for a sd solution. Cleaned and serviced the floppy and made a Norton Portable boot floppy. Startup goes well, bing and onto missing disk, when I insert the floppy it briefly shows a happy Mac does a couple of read noises then spits out the disk. I've also tried a Rascsi on the DB25 with system 6.0.8 on a 40MB Apple drive, holding down Cmnd, Alt, Ctrl, Shift but nothing at all. Is this likely to be another hybrid related issue? and if you think so where can I test voltages to check? Thanks all | |
| Posted by: ironborn65 on 2022-05-15 09:22:45 Hi pal, IMHO you have two issues here: HD and Floppy. HD I was successful in starting it from a SCSI2SD (system 7.5,5) connected to the external DB25, in my case I have to provide an external +5V to the SCSI2SD, I dunno how it works for the Rascsi. Floppy This seems to be a faulty disk or a misaligned head, you might want to connect a known working drive, possibly the one you used to prepare the floppy disk. For the voltages, you could check the external floppy connector, see below, so you don't need to tear it down to reveal the PSU connector. But I do think this is the issue PF  Volgate | |
Posted by: ironborn65 on 2022-05-15 12:35:48For the voltages, you could check the external floppy connector, see below, so you don't need to tear it down to reveal the PSU connector. But I do think this is the issuetypo, I think this is NOT the issue apologies PF | |
| Posted by: timoog on 2022-05-17 12:16:21 Hey thanks for that @ironborn65 I have tried a couple of other floppy drives, might be worth checking again tho. Disk is fine, booted (surprisingly) Q650. Yeah the Rascsi are similar, power over micros usb | |
| Posted by: ironborn65 on 2022-05-17 14:14:01 BTW do not trash the Conner HD, the electronic board might be good as a part for other HD s with good. mechanic and faulty board. The mechanic could also be salvaged with some luck. | |
| Posted by: ironborn65 on 2022-05-21 17:58:12 it's not clear to me if you can now boot from the floppy drive. In case, you can add a SCSI probe application and check if you see the external SCSI drive. Then, if successful, can try to launch system picker to see if it then boots from the SCSI | |
| Posted by: timoog on 2022-05-22 02:36:18 Morning @ironborn65 No still the same, just saying the floppy boots the Quadra | |
| Posted by: ironborn65 on 2022-05-22 04:34:02 are you saying that the same floppy drive and floppy disk which boot fine in the Quadra does not boot in the Portable? And the symptom is "it briefly shows a happy Mac does a couple of read noises then spits out the disk" ? This is weird to me. Can you hear the drive head moving along the tracks? Are you visually inspecting the heads? | |
| Posted by: timoog on 2022-05-22 14:18:04 Aha! Nice one @ironborn65 the Quadra drive was the only one I hadn’t tried, booted from the floppy no problem! It’s odd the older drives haven’t worked, one from the iisi works in that machine. But it’s a good start none the less cheers! | |
| Posted by: timoog on 2022-05-22 15:30:01 Oh =( restart and get a sad mac 03001300/ 00001FFA, I see you had that too @ironborn65, also that it relates to the NMI line(?) any further advice gratefully received | |
| Posted by: ironborn65 on 2022-05-23 01:09:18 in my case the sad mac was a consequence of the missing SWIM, you night have a faulty SWIM, that would explain with you can not boot from the SCSI2SD so: 1 you had the chime and happy mac but it was unable to read the floppy 2 then you installed the quadra known working floppy and it booted 3 now you have a sad mac if you press the reset 4 does it still boot from the floppy if you cold boot? what happened between 2 and 3? which are condition of the board? are traced, via and pads ok? Did capacitors leak? Any sign of gunk around ICs? Do a close inspection of the SWIM and its pins | |
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