Apple Disk II Technical Procedures

System SetupFor the analog card to be correctly diagnosed, it must be theonly unknown variable in the test system. Using all knowngood,verified components, assemble them as follows:1. Place the analog card to be tested on the DRIVE 2mechanical assembly and connect all cables.2. Place the disk controller card in slot 6 of the Apple//e.Visual InspectionExamine the suspect analog card for visual signs of damage.This may take one of several forms:1. Burned or melted ICs or sockets. Remove each of the fourICs and closely examine them and the sockets. Replaceall damaged ICs with good ones. Return all analog cardswith damaged sockets to Apple.2. Capacitor C4 (large capacitor at corner of card) may bevisibly damaged (burned, exploded, melted). Observingcorrect polarity (match the + of the capacitor to the +on the analog card), replace C4 if it is damaged. If C4is damaged, the 7 4LS125 is also damaged and should bereplaced.3. Components other than the four ICs and capacitor C4 maybe physically damaged and in need of replacement. Thesecards should be returned to Apple for repair.WARNING: Do not use an eraser to clean gold contacts. Useonly a liquid or spray contact cleaner and a cleancloth.TroubleshootingA malfunctioning analog card may manifest symptoms in one offive ways:Drive 1 will not boot (with bad drive 2 analog cardconnected) .Drive will not read or write (could destroy data).Drive has trouble reading.Drive has trouble writing.Write protect switch circuit malfunctions.A troubleshooting procedure for each failure mode follows.Disk ][ Analog Card rev Jun 84 Page 5.5