Use of DDR2-RAM-modules: issues with T60 (and with Dell D520)

[BigCatAndy]

Hello dear community,

some time ago I wanted to insert 2 RAM-modules in T60 (1 GB + 2 GB). They were from the same vendor (Hynix, I suppose), but somehow T60 did not boot. It started, but screen remained black (and in some case I heard 4 pips) and I had to switch it off and recombine modules. At the end I found working combination, but I was really surprised by this conflict. I thought, that all DDR2-modules were compatible with each other.

Can anyone give me a hint on it? Are there "incompatible" DDR2-modules?
Thanks from Hamburg.

P.S. I think, same conflict I already experienced with Dell D520. In the case of Dell it did not start at all, only one LED (CAPSLOCK, as far as I remember) was blinking. The solution was the same - re-combine RAM modules until they match.

[kfzhu1229]

Hello dear community,

some time ago I wanted to insert 2 RAM-modules in T60 (1 GB + 2 GB). They were from the same vendor (Hynix, I suppose), but somehow T60 did not boot. It started, but screen remained black (and in some case I heard 4 pips) and I had to switch it off and recombine modules. At the end I found working combination, but I was really surprised by this conflict. I thought, that all DDR2-modules were compatible with each other.

Can anyone give me a hint on it? Are there "incompatible" DDR2-modules?
Thanks from Hamburg.

P.S. I think, same conflict I already experienced with Dell D520. In the case of Dell it did not start at all, only one LED (CAPSLOCK, as far as I remember) was blinking. The solution was the same - re-combine RAM modules until they match.

These strange issues can happen even though the manufacturers are the same.
I had this same issue with a T43 and a Latitude D610 with the 1GB DDR2 sticks. Somehow I have to match a Kingston with a Hynix on both of them for both to work!
Also, on the D520, flashing caps lock equals to 4 beeps on a ThinkPad, bad RAM. It is intentional and will display this or other RAM error codes every time RAM prevents it from POSTing.

[axur-delmeria]

Having had similar experiences on X61's over the years, I ended up with a simple technique: boot the machine without any RAM installed. This will (hopefully) clear any stored RAM timing data in the machine.

[BigCatAndy]

These strange issues can happen even though the manufacturers are the same.
I had this same issue with a T43 and a Latitude D610 with the 1GB DDR2 sticks. Somehow I have to match a Kingston with a Hynix on both of them for both to work!
Also, on the D520, flashing caps lock equals to 4 beeps on a ThinkPad, bad RAM. It is intentional and will display this or other RAM error codes every time RAM prevents it from POSTing.

Thanks for the information. This is very goo to know, that it happens sometimes.
Regards,
Andrey