Editing Atari Mega ST Troubleshooting (section)

=== DRAM Failure ===

The Mega ST uses soldered DRAM — 8 × 41256 (256 Kbit × 1) chips for a 1 MB configuration, or 32 × 41256 for 4 MB. A single failed chip will cause the CPU to halt on memory test.

'''Diagnosis:'''
* Random crashes, data corruption → suspect marginal DRAM
* Consistent halt at specific address → identify the failed chip by decoding the address bus
* Use a logic analyser or scope on address lines A0–A21 to determine which bank and bit is failing
* Replacement requires desoldering; use a hot-air station to avoid pad damage