Originally posted by lotech which pins responsible for the AA ??
No idea, I don't have a grip. But basic troubleshooting procedure for anything is start at the beginning and check at each place you can. So first make sure the batteries are in correctly. I know that's obvious but I have put AA's in wrong by accident and wasted time because of it.
Then look at the battery tray, there should be some type of contacts, use a mult-tester and check for voltage. With 6 AA's you should be getting somewhere between 7 and 9 volts on one set of contacts. You won't hurt anything by testing if you use a multi-tester.
Voltage on the contacts? Then the batteries are OK, in properly and the tray is working. Therefore the problem is further down the line, possibly the contacts in the grip.
No voltage on the contacts? Then one of the above is the problem, recheck everything.