Did you even read the datasheet of the H5AN8G8 before testing these devices and doing things like "By upping the DRAM voltage from 1.5V to 1.55V" ?
Absolute Maximum DC Ratings : VDD Voltage on VDD pin relative to Vss : -0.3 ~ 1.5 V
-> 1. Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
So every test after these settings might be affected and should be redone with new memory. Even setting it to 1.5V might be above these limits since there is some tolerance on the regulators.
You shouldn't recommend this to your reader as settings for 4600 & 4666 because it can damage their memory.