ERROR: RAM memory selftest failed.
This error can be caused by numerous reasons. In most cases, it's due to bad connection (unstable NRST signal line), or RTCK/TCK sampling rate too high.
User should check connection, and adjust RTCK/TCK sampling rate to lower value:
This can be also target device problem. DCC loader upon startup checks target device RAM (if external RAM is used) and in case that selftest fails, it will return this error. Easiest was to diagnose this is to run generic DCC loader DLL.
Generic DLL-s use internal MCU SRAM, and in case that You can boot target device without problems using generic DLL, and with model specific You have this error, it's hardware problem.
Example - HTC Desire DLL returns "RAM memory selftest failed." error, while QUALCOMM QSD8xxx NAND works without errors.