According to the manual for your motherboard you have four memory slots. Two are coloured green, two are coloured orange.
The manual also specifies the following things:
- Your board supports either DDR1 or DDR2. However you can not mix these two. You need to use either all DDR2 or all DDR1. You wrote that the new DIMM is
DDR2 667. Check if your old DIMM is also DDR2
- Your motherboard support dual channel memory access if you put one DIMM in a green bank and one identical DIMM in the matching orange bank. You can not always do this if the DIMMs have different timings. (Sometimes the MB/BIOS will select the slowest combination of both timings, sometimes it just will not work).
First remove both DIMMs. Put them net to each other and compare the notches to check if both are DDR2. This picture from Wikipedia might help.
If they do not match you simply can not use both.
If they both are DDR2 then try to boot the motherboard with one DIMM. Try both of them. This will verify that your computer is compatible with the new DIMM. (They usually are, but sometimes boards and DIMMs do not work well in combination, without any clear reason).
Check the timings for the DIMMs. Are they equal speed (same CAS, RAS, ...)? DoO they require equal voltage? If they match it should work if you put one DIMM in the first green slot, and one in the matching orange slot. If it does not try moving both to the green slots, which will use both DIMMS as single channel, rather then trying to combine the two into dual channel access
If this does not work either then please add more details to your original post.
Specifically expand and clarify the part where "I tried different combinations and the only one that gives me something different".
(Something different? Just what is different?)