DG965RY 2GB + 1GB RAM not working together

Are the memory modules installed like this?

Channel A, DIMM 0 = 1GB
Channel B, DIMM 0 = 2GB
Channel A, DIMM 1 = 1GB
Channel B, DIMM 1 = Empty

What are the part numbers of your memory modules?

It normally is written on a sticker on each module. You could also use Cpu-Z - the modules info will be available from the SPD tab. Check all slots that contain a memory module.

That Intel motherboard is picky with memory.

You could contact Transcend and ask them why they don't work. Those modules are not on Intels list of certified modules, but they should work just fine. The BIOS might also have been modified at some point and no longer support your configuration. An email to Intel support would answer that question.

Why didn't you buy two modules? If you wanted to add 2G, then you should have bought 2 modules identical to the ones that you already had. Dual-channel provides better memory performance.

If adding one more JM667QLU-2G module doesn't work with the existing modules, then just sell the JM667QLJ-1G modules. You'll still have 4GB and it will work. Before doing it I would confirm with Transcend that they will work.

u can use kvr800d2n5/2g