Macintosh SE Troubleshooting: Difference between revisions
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Expand troubleshooting: add common faults (RIFA/PRAM battery/recap/ROM-disk/SCSI), cited from 68kMLA/recapamac/etc. |
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* '''Wavy display''' = failing flyback transformer | * '''Wavy display''' = failing flyback transformer | ||
* '''Clicking power supply''' = logic board short or bad startup circuit ('''CR2/CR3''', '''Q2''', '''R22''') | * '''Clicking power supply''' = logic board short or bad startup circuit ('''CR2/CR3''', '''Q2''', '''R22''') | ||
== Power supply and startup == | |||
The SE was fitted with one of two switch-mode power supplies (an international/Astec type and a Sony type). A tired PSU shows as no start-up, a repeated ticking/clicking, or unstable rails; recap or substitute the supply and confirm '''+5 V''' (4.90–5.10 V) and '''+12 V''' before chasing logic-board faults.<ref name="mac_compact">[https://recapamac.com.au/ Recap-a-Mac] and the [https://68kmla.org/ 68k Macintosh Liberation Army (68kMLA)] forum — community references for compact-Macintosh power-supply, analog-board and capacitor faults.</ref> The SE shares its analog board with the [[Macintosh SE/30]]; the detailed analog-board and minimal-boot diagnostics on the [[Macintosh SE/30 Troubleshooting]] page apply directly. | |||
== PRAM battery == | |||
The SE carries a 3.6 V 1/2AA lithium PRAM battery on the logic board. Old cells leak, and the electrolyte corrodes nearby traces and vias; remove a leaking battery immediately, neutralise and clean the residue with isopropyl alcohol, and repair any broken traces before troubleshooting further. A flat battery loses the clock and settings and can cause boot hangs.<ref name="mac_compact" /> | |||
== Recap first == | |||
Before chasing any intermittent fault on an SE, replace the electrolytic capacitors on the logic board and inspect the analog board. Leaking electrolytics cause a large share of compact-Mac faults — simasimac, no boot, distorted sound, video instability and random resets — and their residue corrodes traces.<ref name="mac_compact" /> | |||
== Storage: SCSI and modern replacements == | |||
The SE uses the NCR 53C80 SCSI controller for its internal hard disc. Failing period drives (stiction, dead boards) are common; a modern solid-state replacement such as a '''BlueSCSI''' or '''SCSI2SD''' is the usual fix. Check the SCSI bus termination, and note that some SCSI adapters need termination power (TERMPWR) supplied to work reliably.<ref name="mac_scsi">[https://www.crackedthecode.co/replacing-failed-capacitors-in-a-macintosh-computer/ Cracked the Code] and [https://www.ifixit.com/Device/Macintosh_plus iFixit] — compact-Macintosh SCSI, RIFA and PRAM-battery notes.</ref> | |||
== References == | |||
<references /> | |||
== Related Pages == | == Related Pages == | ||