myoldmac.net wrote:
On Mar 9, 10:54 am, "Michael J. Mahon" <mjma...@aol.com> wrote:biel...@terra.es wrote:On Mar 9, 5:48 am, "myoldmac.net" <use...@myoldmac.net> wrote:Can you exactly tell me the name or position of this maybe blown up chip (it smelled a bit after first launch...)Sometimes I managed to blow the 74ls125 in the drive's analog card, and sometimes another one (I don't remember which) in the controller card...Right, and the smell--and likely its appearance--will lead you to it. -michael NadaNet networking for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."Hi, I added another Disk ][ from my //e and it works fine - so the new arrived Disk ][ seems to be defected. I will try cleaning and head recalibration.
Glad to hear that a chip isn't fried! I had an intermittently shorting disk cable once, and when the short occurred, it put +12v into that '125 and made it much too hot to touch, and smell like it was about to "release the magic smoke". But after I fixed the cable, the severely mistreated chip still worked. TTL chips are a wonder of reliability. ;-) And, as Jorge pointed out, *don't* attempt to recalibrate your drive. That's a very improbable failure (unless the drive was dropped to the floor in just the wrong attitude), and a "repair" with a high probability of failure, particularly in the absence of "known good" disks. ;-) If the Glyptol on the seek stepper mounting screws is undisturbed, then the seek alignment is probably fine. -michael NadaNet networking for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."