New RAMs troubles: reviving an old HP Compaq 6720s

[necronlord_90]

Hi there!
I'm struggling to revive an old PC, a HP Compaq 6720s.
I know that is an old piece of low-tech, but is almost new (my main PC used to work well at that time) and I need something to study with.
And no, I cannot afford to buy a new computer because...you know...though time...

This PC can store up to 4Gb of RAM in two separate slots (Motherboard: Hewlett-Packard 30D8 (U10)).

I bought a set of 2x DDR2 2Gb RAM manufactured by Hynix (yes they are the right kind of RAM, I doublechecked many times before purchasing them) to replace the poor standard 1Gb memory.
This is a picture of the twin set of RAM

Spoiler

The problem is the following: if I do put both the 2Gb RAM in the PC (it is a twin set) it won't turn on and will just cycle beetween the BIOS and the starting Windows' logo.
The new RAMs are fine and so are the slots, in fact if I do place them separately in one or the other slot the PC turns on correctly).

Please, can you try to explain me why is this happening and how can I solve (if possible) the problem?

P.S. I'm sorry for my terrible English.

 

[popatim]

Crucial has a kit they guarantee is compatible.

Not sure whats going on with what you bought, perhaps due to the different memorychip configuration.