No power after chaning palmrest

Hello

I would like to say thank you ahead of time to everyone on here. This forum has helped me a million times.

I changed the palm rest on my 2007 MBP 15"(2.4C2D/4GB/250GB). The keys will old and falling off. So I bought a full palm rest with keyboard and trackpad.

Before putting it all back together I did a power on test and it passed. But I only put one stick of ram in when I did this.

So I put it back together and try to boot, and I get 3 blinking lights. Take it apart again. Reseat the memory. Power on, Still no POST.

After messing with for about 30 min. I noticed. The computer will only POST if I have memory in memory slot #1, if there is two sticks it will never POST. It won't post with either stick in slot #2. But it does POST with either stick in slot#1.

I tried clearing PRram and SMC. I tried cleaning with contact cleaner. Stil no luck. I even put another good/tested stick of ram and still not post. This was a working laptop with 4GB before I took it apart. What did I do wrong?

Would the system board go bad that quickly?

Sorry for the long drawn out explanation. I hope someone here can help me.

Thanks again in advance.

Andy P