david1@mhuxu.UUCP (Rick Nelson) (10/26/87)
>Rick > >Sounds like we're on the right track. Did you remove or otherwise check >the other diode? Some times they look ok but the connections are still >bad. Remove the diode and clean the leads and re-solder. Let me know >what happens also which diode cracked? It may help in determining what >the problem is. > >Mike I replaced both diodes, CR15 and CR16 I think are their numbers. OThe voltage across them is about 5V. Does this sound right? When I put a disk in the drive and close the handle, the drive makes a noise for only a moment, (you know the sound, whatever it is). The busy light stays on, but the disk never turns and when I turn on the computer I get the disk boot error message. It costs $90 to have drives repaired around here and you can get a new one for around $135-140. It seems that they're a throw away item if one can't fix it themself. To answer your question, I think it was CR15 that was the diode that was cracked and the first one replaced. Have any other suggestions? Your considerations are greatly appreciiated. Thanks Rick Nelson mhuxu!david1 PS I got the following reply when I tried to send you mail: We have been unable to contact machine 'ucbvax' since you queued your job. ucbvax!mail xerox.com!ishler.wbst (Date 10/21) The job will be deleted in several days if the problem is not corrected.
rich@lakesys.UUCP (10/28/87)
> >I replaced both diodes, CR15 and CR16 I think are their numbers. OThe voltage >across them is about 5V. Does this sound right? When I put a disk in the >drive and close the handle, the drive makes a noise for only a moment, (you >know the sound, whatever it is). The busy light stays on, but the disk never >turns and when I turn on the computer I get the disk boot error message. > Here's a bit of advice that just may solve your problems. In the above I noticed that you have replaced the diodes and are now on the lookout for possible bad solder connections. My suggestions is that you replace the whole Bridge Rectifier system, and also the 5 Volt regulator. I have had many a 1050 drive in my hands for repair and for the most part the 5 volt reg was the problem. The voltage on the side of the diode, ( CR15 I think -- the one comming directly from the bridge ) should be about 22 volts. If it's low, you probably have a leaky diode in the bridge, so just replace all 4 diodes in the bridge. Replacesment of the 5 volt regulator is cheap insurance, so I would also opt for that. Just rememer to get the rigth polarity regulator. Wouldn't want to pop the wrong voltage potential around the drive, which would make the whole situation worse. -rich Lakesys & Milwaukee | Who & where ????? A great place by a great lake..... UUCP: {Ihnp4,uwvax}!uwmcsd1!lakesys!rich Discalimer: The words,ideas,and expressions are my own, and not nessasarily always correct, but i'm pretty sure about this one!