Newsgroups: comp.sys.apple2 Path: news.weeg.uiowa.edu!news.uiowa.edu!hobbes.physics.uiowa.edu!moe.ksu.ksu.edu!crcnis1.unl.edu!wupost!howland.reston.ans.net!agate!dog.ee.lbl.gov!network.ucsd.edu!newshub.nosc.mil!nosc!crash!pro-nsdapple!tomk (Smail3.1.28.1 #7) id m0nQuXE-0000WYC; Mon, 22 Feb 93 23: 58 PST From: tomk@pro-nsdapple.cts.com (Tom Kelly) Subject: Re: Repair File Wanted Organization: ProLine [pro-nsdapple] - North San Diego Apple Users Group Date: Mon, 22 Feb 93 22:06:25 PST Message-ID: In-Reply-To: sjensen@eis.calstate.edu (Steve Jensen) References: Lines: 10 The best way to fix Disk ][ drives is to swap parts. First swap the analog card from a good drive to a bad drive. The analog card is the card on top when you remove the cover. The cover slides to the rear toward the cable after you have removed its 4 screws. If that fixes the problem then swap chips from bad to good to find out what chips are bad. If you plug the 20 pin cable backwards you usually blow the 2003 chip. The chips each cost around $1.00 to $3.00, so fixing a drive is NOT expensive. Path: news.weeg.uiowa.edu!news.uiowa.edu!hobbes.physics.uiowa.edu!math.ohio-state.edu!cs.utexas.edu!geraldo.cc.utexas.edu!sleepy.cc.utexas.edu!not-for-mail From: foegelle@sleepy.cc.utexas.edu (Michael Foegelle) Newsgroups: comp.sys.apple2 Subject: Re: ][+ troubleshooting Date: 9 Dec 1993 12:12:01 -0600 Organization: The University of Texas - Austin Lines: 45 Distribution: comp Message-ID: <2e7pph$gh6@sleepy.cc.utexas.edu> References: <1993Dec7.200153.10907@porthos.cc.bellcore.com> NNTP-Posting-Host: sleepy.cc.utexas.edu In article <1993Dec7.200153.10907@porthos.cc.bellcore.com>, Christopher Wood wrote: >In article , mort@apollo.hp.com (Stephen Moriarty) writes: > >|> I have a ][+ that I'm troubleshooting for a friend. > >[ ][+; replaced chips on controller, still won't boot disks ] > >Sounds like you have a disk speed problem. There's a potentiometer on >the disk II (you have to open up the case to get to it) that adjusts >the speed at which the drive runs. > >My suggestion would be to hook the misbehaving floppy drives to a >controller in slot 5 in a working system, and get a program like >CopyII+ or locksmith to check your drive speed. So you need to have >at least one working drive on the same system as the faulty ones, so >you can boot up the software. The other option, for a system without a working drive, is to remove the bottom cover as well as the top, flip the drive over (or on the side) and illuminate it with a fluorescent lamp (and preferably nothing else). Then (assuming you're in the US) adjust the speed control until the marks labelled '60' are standing still. In Europe use the marks labelled '50'. That's the original timing method. However, if NO disks are booting, that probably means one or more of the chips on the DRIVE, not the controller card, are bad. Typically it's the quad buffer chip (74LS121 or something like that) that gets blown. If so, chances are you're ruining every disk you try to boot in the drive too. Thus, even when you FIX the drive, those disks will no longer boot! > >Chris > >-- >Chris Wood Bellcore ccw@ctt.bellcore.com > Michael Foegelle -- Michael Foegelle | Call Wunderland BBS! | foegelle@ccwf.cc.utexas.edu University of | (512) 472-0544 8n1 | foegelle@utaphy.ph.utexas.edu Texas at Austin | 14.4kbaud, v.32/bis | GEnie: M.FOEGELLE2 Physics Department | 500 megs on a //e! | > Ask me about Columns //e! <