No boot after adding memory

[andrei186]

I have two 7 years old PCs of the same model of the same manufacturer with 256 Mb memory. I am trying to upgrade one PC by adding the 256 Mb memory chip from another.
It would not boot at all. I mean absolutely at all. I.e. black screen, not a single flash or noise (BTW these PCs boot without that standard double beep).
Removed the mamory chip - boots OK.
Added this same chip to a third computer (of a different model) - it boots and recognizes the upgrade.
What am I doing wrong?

 

[clarkjd]

It's possible that the two memory cards are incompatible with each other.

 

[andrei186]

thank you. How do I make sure that they are incompatible indeed? They look identical

 

[clarkjd]

Do they both work by themselves in each computer?

 

[andrei186]

yes, they do. Of course before writing here I made sure that both memory chips are in working order

 

[clarkjd]

Run CPU-z with each stick. check to see that they have the exact same timings, etc. If not, then you will have to set your BIOS to the slower settings of the two ram modules.

 

[legendkiller]

I'd check the timing and speed of RAM.. I got a Sansung and A Kingston(both ddr2) which that is at same timing and same clock speed and is 1GB each.. Works find, get CPU-Z and check if there's any different in timing and speed... For example, one of the is a 6-7-6-10 awhile the other one is 6-6-6-10(Just examples not real timings) and clock speed at 677 awhile the other is 600

 

[andrei186]

Thank you
downloaded CPU-Z and run it with each memory chip. It was identical except
on the first one
RAS# to CAS# delay (tRCD) 3
RAS# Precharge (tRP) 3

while on the second
RAS# to CAS# delay (tRCD) 4
RAS# Precharge (tRP) 4

Another difference was on the SPD tab. The first chip reads
JEDEC timings table
JEDEC #1 2.5-3-3-7-n.a. @ 166 MHz
JEDEC #2 3.0-3-3-8-n.a. @ 200 MHz

while the second reads
JEDEC #1 3.0-4-4-8-n.a. @ 200 MHz

What should I do?

 

[legendkiller]

Go into bios and change it to the same timings by lowering the second one to the first one like 3.0 to 2.5 and 8 to 7 with the speed to 166... if you have problem, take pics in bios and let us know.. BTW i dont know how to take pic in bios either too so ask some other people who know LOL if you dont know... And also if you make the first one going up to the second one with the speed and timings, i dont think it works but you can try to make your computer faster (a tiny bit which is unnoticeable)

 

[andrei186]

while awaiting a reply I did not know how to occupy myself, and just swapped the memory chips in the slots - put the second chip into the first slot and the first chip into the second slot and... it worked. Why?

 

[legendkiller]

I do not know why but one of my theory would be that the bigger is the leader, in this case it's probably because the timing and speed on the first one changed the second to the same as the first one, check timings and speed or use Everest/aida64 which should tells everything...

 

[andrei186]

Most helpful, thank you very much

 

[legendkiller]

We didn't help at all, you did it yourself LOL... You solved your own problem by changing the Memory Slot XD...