STFM RAM Diagnostics

[tzok]

If you have an oscilloscope, try to observe address lines and Din/Dout lines of DRAM chips while rebooting the system. Look for lines that are always high or always low, or never reach the right voltage levels.If a chip is faulty it may short Din/out (D/Q), or its address lines to GND or Vcc, and then isolating it by disabling CAS/RAS signals won't help much.

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[Steve]

If you have an oscilloscope, try to observe address lines and Din/Dout lines of DRAM chips while rebooting the system. Look for lines that are always high or always low, or never reach the right voltage levels.If a chip is faulty it may short Din/out (D/Q), or its address lines to GND or Vcc, and then isolating it by disabling CAS/RAS signals won't help much.

MT1259.png

Thanks tzok that's great info