4 slot board problems

I have this posted in another forum but I also thought I would also put in the NEO forums. I have been having some probs with my 4slot pcb. It would only boot to the green screen. I have twice replaced the crystal only to have it work great for a day each time and then go back to the green screen/calendar error. I have taken Channelmaniac's advice and checked the D4990 chip and I am getting the 5V between pin 7 and 14. Is there anything else I should be checking in that area? Thanks

Doug

Did you remove the battery from the board and running it with no battery?

Yes, it has been removed until I get a replacement. Will this make a difference?

Well. I took the board today and made sure it was good and clean. I give it another cleaning with some water and baking soda to make sure there was no acid residue left. I checked all the traces around the battery area and then re flowed all of the components in that area. I put all the dips to ON and turned it on to the work ram test. It sat on that for about one hour, I powered off, reset the switches, powered back on and booted right into Aero Fighters. Could it have just been a bad joint somewhere?

Probably just a connection issue between the boards.