Macintosh IIvx Troubleshooting: Difference between revisions

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[[File:Macintosh IIvx (photo).jpg|thumb|right|300px|Macintosh IIvx. Source: Wikimedia Commons.]]

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|+ '''Power Issues'''

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See [[Macintosh IIvx Capacitor Replacement Guide]] for procedures.

== ⚠️ PRAM battery — remove it now ==

The Macintosh IIvx carries a 3.6 V 1/2AA lithium PRAM battery. These leak and can '''burst''', spraying corrosive electrolyte across the logic board and destroying nearby components — often while the machine simply sits in storage. '''Remove the PRAM battery from any un-serviced unit.''' If one has leaked, neutralise and clean the residue and repair corroded traces and vias before troubleshooting.<ref name="mac2_batt">[https://68kmla.org/bb/threads/warning-exploding-maxell-pram-batteries.25169/ "Warning! Exploding Maxell PRAM Batteries"], 68kMLA; and [https://macdat.net/macintosh/macii/macintosh_iicx.html MacDat — Macintosh II family]. Source for the leaking/exploding lithium PRAM battery that destroys nearby components.</ref>

== ⚠️ Surface-mount capacitor leakage ==

The Macintosh IIvx logic board uses surface-mount electrolytic capacitors that leak with age and corrode the board; '''recap and clean the logic board''' as a first step, then recap the power supply.<ref name="mac2_cap">[https://macdat.net/macintosh/macii/macintosh_iicx.html MacDat — Macintosh IIcx/II family]; and 68kMLA recap threads. Source for the Mac II-family surface-mount electrolytic logic boards that leak and corrode with age and must be recapped.</ref>

== Power supply ==

The desktop power supply uses electrolytic capacitors that fail with age. The classic symptoms are a machine that will '''rarely turn on, cannot be switched off without unplugging it, and clicks from the PSU when merely plugged in'''. Recap the power supply and confirm the +5 V and +12 V rails. (This PSU form factor is shared across the IIci, IIcx, IIvi, IIvx, Performa 600, Quadra 650 and Quadra 700.)<ref name="mac2_psu">[https://68kmla.org/bb/threads/compact-desktop-power-supply-capacitor-lists-by-make-and-model.35890/ "Compact/Desktop Power Supply Capacitor Lists (by make and model)"], 68kMLA; and [https://www.bigmessowires.com/2016/04/21/capacitor-replacement-in-a-vintage-power-supply/ "Capacitor Replacement in a Vintage Power Supply"], Big Mess o' Wires. Source for the shared desktop PSU form factor (IIci/IIcx/IIvi/IIvx/Performa 600/Quadra 650/Quadra 700), the electrolytic failure symptoms and the PSU capacitor lists.</ref>

== References ==

== Component-level faults (deep dive) ==

=== Surface-mount capacitor leakage ===

The Macintosh IIvx logic board uses surface-mount electrolytic capacitors whose electrolyte turns corrosive with age and creeps across the board, eating through traces, pads and IC pins. Typical signatures are a machine that will not chime, chimes but shows no video, plays distorted or missing audio, or shows a garbled or checkerboard screen. Wash the affected area and replace every electrolytic with a tantalum or polymer part, then repair any lifted traces. The switch-mode power supply (ASTEC or TDK on the LC-family machines) holds its own electrolytics and fails the same way, so recap it alongside the board.<ref name="caps">Mac84, [https://mac84.net/web/macintosh-lc-series-lc-lc-ii-lc-iii-power-supply-recapping-guide-astec-usa/ Macintosh LC series power-supply recapping guide]; the [http://www.maccaps.com/MacCaps/Capacitor_Reference/Capacitor_Reference.html MacCaps capacitor reference]; and iFixit. Source for surface-mount electrolytic leakage eating traces, pads and pins, the ASTEC/TDK LC power-supply cap failures, and Apple's use of tantalum (non-leaking) capacitors on the Quadra 700/900 logic boards.</ref>

=== PRAM battery ===

The Macintosh IIvx backs up its clock and Parameter RAM from a 3.6 V ½AA lithium cell. These cells — red Maxell parts especially — leak or burst and corrode the board, so remove an aged one on sight. A flat cell can also stop a soft-power machine booting or disturb the video; left plugged in, trickle power preserves the settings, but a machine switched off at the wall with a dead cell loses them. Clean the area and fit a fresh 3.6 V cell.<ref name="pram">[https://68kmla.org/bb/threads/warning-exploding-maxell-pram-batteries.25169/ Warning! Exploding Maxell PRAM batteries], 68kMLA; and [https://www.macdat.net/repair/kb/batteries_macintosh.html Mac Battery Leaks], MacDat. Source for the 3.6 V ½AA lithium PRAM cell, the Maxell leak/explosion board damage, and soft- versus hard-power PRAM retention.</ref>

=== Boot chime and Sad Mac ===

Read the start-up sound first: a normal chime with a black screen points to the display path or the monitor, an absent chime or a "chord of death" points to RAM or a core fault, and a Sad Mac shows a numeric code — see [[Sad Mac Error Codes]].

== Related Pages ==

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+[[File:Macintosh IIvx (photo).jpg|thumb|right|300px|Macintosh IIvx. Source: Wikimedia Commons.]]
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 |+ '''Power Issues'''
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 See [[Macintosh IIvx Capacitor Replacement Guide]] for procedures.
+== ⚠️ PRAM battery — remove it now ==
+The Macintosh IIvx carries a 3.6&nbsp;V 1/2AA lithium PRAM battery. These leak and can '''burst''', spraying corrosive electrolyte across the logic board and destroying nearby components &mdash; often while the machine simply sits in storage. '''Remove the PRAM battery from any un-serviced unit.''' If one has leaked, neutralise and clean the residue and repair corroded traces and vias before troubleshooting.<ref name="mac2_batt">[https://68kmla.org/bb/threads/warning-exploding-maxell-pram-batteries.25169/ "Warning! Exploding Maxell PRAM Batteries"], 68kMLA; and [https://macdat.net/macintosh/macii/macintosh_iicx.html MacDat &mdash; Macintosh II family]. Source for the leaking/exploding lithium PRAM battery that destroys nearby components.</ref>
+== ⚠️ Surface-mount capacitor leakage ==
+The Macintosh IIvx logic board uses surface-mount electrolytic capacitors that leak with age and corrode the board; '''recap and clean the logic board''' as a first step, then recap the power supply.<ref name="mac2_cap">[https://macdat.net/macintosh/macii/macintosh_iicx.html MacDat &mdash; Macintosh IIcx/II family]; and 68kMLA recap threads. Source for the Mac II-family surface-mount electrolytic logic boards that leak and corrode with age and must be recapped.</ref>
+== Power supply ==
+The desktop power supply uses electrolytic capacitors that fail with age. The classic symptoms are a machine that will '''rarely turn on, cannot be switched off without unplugging it, and clicks from the PSU when merely plugged in'''. Recap the power supply and confirm the +5&nbsp;V and +12&nbsp;V rails. (This PSU form factor is shared across the IIci, IIcx, IIvi, IIvx, Performa 600, Quadra 650 and Quadra 700.)<ref name="mac2_psu">[https://68kmla.org/bb/threads/compact-desktop-power-supply-capacitor-lists-by-make-and-model.35890/ "Compact/Desktop Power Supply Capacitor Lists (by make and model)"], 68kMLA; and [https://www.bigmessowires.com/2016/04/21/capacitor-replacement-in-a-vintage-power-supply/ "Capacitor Replacement in a Vintage Power Supply"], Big Mess o' Wires. Source for the shared desktop PSU form factor (IIci/IIcx/IIvi/IIvx/Performa 600/Quadra 650/Quadra 700), the electrolytic failure symptoms and the PSU capacitor lists.</ref>
+== References ==
+<references />
+== Component-level faults (deep dive) ==
+=== Surface-mount capacitor leakage ===
+The Macintosh IIvx logic board uses surface-mount electrolytic capacitors whose electrolyte turns corrosive with age and creeps across the board, eating through traces, pads and IC pins. Typical signatures are a machine that will not chime, chimes but shows no video, plays distorted or missing audio, or shows a garbled or checkerboard screen. Wash the affected area and replace every electrolytic with a tantalum or polymer part, then repair any lifted traces. The switch-mode power supply (ASTEC or TDK on the LC-family machines) holds its own electrolytics and fails the same way, so recap it alongside the board.<ref name="caps">Mac84, [https://mac84.net/web/macintosh-lc-series-lc-lc-ii-lc-iii-power-supply-recapping-guide-astec-usa/ Macintosh LC series power-supply recapping guide]; the [http://www.maccaps.com/MacCaps/Capacitor_Reference/Capacitor_Reference.html MacCaps capacitor reference]; and iFixit. Source for surface-mount electrolytic leakage eating traces, pads and pins, the ASTEC/TDK LC power-supply cap failures, and Apple's use of tantalum (non-leaking) capacitors on the Quadra 700/900 logic boards.</ref>
+=== PRAM battery ===
+The Macintosh IIvx backs up its clock and Parameter RAM from a 3.6&nbsp;V &frac12;AA lithium cell. These cells &mdash; red Maxell parts especially &mdash; leak or burst and corrode the board, so remove an aged one on sight. A flat cell can also stop a soft-power machine booting or disturb the video; left plugged in, trickle power preserves the settings, but a machine switched off at the wall with a dead cell loses them. Clean the area and fit a fresh 3.6&nbsp;V cell.<ref name="pram">[https://68kmla.org/bb/threads/warning-exploding-maxell-pram-batteries.25169/ Warning! Exploding Maxell PRAM batteries], 68kMLA; and [https://www.macdat.net/repair/kb/batteries_macintosh.html Mac Battery Leaks], MacDat. Source for the 3.6&nbsp;V &frac12;AA lithium PRAM cell, the Maxell leak/explosion board damage, and soft- versus hard-power PRAM retention.</ref>
+=== Boot chime and Sad Mac ===
+Read the start-up sound first: a normal chime with a black screen points to the display path or the monitor, an absent chime or a "chord of death" points to RAM or a core fault, and a Sad Mac shows a numeric code &mdash; see [[Sad Mac Error Codes]].
 == Related Pages ==