Editing Sad Mac Error Codes (section)

== SE/30 Specific Issues: Simasimac ==

[[File:Simasimac issue.jpg|thumb|right|''"Simasimac" vertical stripes'']]

A common [[Macintosh SE/30|SE/30]] failure mode is known as '''Simasimac''' (Japanese ''shima-shima'' "stripes" + Mac), in which the screen shows alternating vertical stripes at power-on with '''no chime''' and '''no Sad Mac'''. Because the CPU never reaches the point of checksumming ROM and drawing the failure screen, this is not technically a Sad Mac fault at all — it is a more upstream failure.

The cause is almost always corroded traces and via stitching from leaking surface-mount electrolytic capacitors on the logic board, particularly around the [[Glue Logic|GLU]] ASIC and the ROM SIMM socket. Common diagnostic steps:

# Remove the logic board and inspect under good light — even small green/black halos around capacitor pads are evidence of leakage.
# Wash the board (deionised water + isopropanol, ultrasonic if available), let it dry thoroughly.
# Recap with quality polymer or tantalum replacements; the original wet-electrolytic capacitors are at end-of-life on every SE/30 still in existence.
# Reseat the ROM SIMM with contacts cleaned with isopropanol and a fibreglass pen.
# Check continuity from the 68030 data lines through the GLU to the ROM SIMM socket. Lifted vias here are common.

If the machine then chimes but produces a Sad Mac, treat it as a normal expanded-format diagnosis from that point.

For full procedure see [[Macintosh SE/30 Capacitor Replacement Guide|Macintosh SE/30 Recap Guide]] and [[Macintosh SE/30 Troubleshooting]].