Editing Atari STE Troubleshooting Guide (section)

== Diagnostic Flowchart (STE-Specific) ==

# '''Check PSU:''' Measure +5V and +12V under load. Recap if necessary.
# '''Check SIMMs:''' Remove and reseat all SIMMs. Clean contacts. Try known-good modules.
# '''Reseat all socketed ICs:''' CPU (if DIP), TOS ROMs, WD1772, YM2149, MFP, ACIAs, BLiTTER.
# '''Try diagnostic cartridge:''' Works the same as on the ST. Serial output is available for headless diagnosis.
# '''Check TOS ROMs:''' Swap with known-good set. Upgrade to TOS 2.06 if on TOS 1.62.
# '''Check clocks:''' Verify 32 MHz master crystal and 8 MHz SCLK oscillator.
# '''Check GST MCU/Shifter:''' If all above are good, fault is likely in the surface-mount custom ICs. Inspect solder joints under magnification. Professional reflow may be required.