Canon 50D Grip problem with LCD

Just replaced the shutter in my 50D via CPS and everything seemed fine until I went to attach the grip back to the camera. I get no LCD screen when the grip is attached. Everything seems fine without the grip installed and single battery but as soon as I attach it, no LCD. I can shoot, top LCD screen works and I can change settings but nothing on the main LCD.

Worked fine before the shutter failure. Any correlation between replacing a shutter and a grip suddenly not working?

Thanks

Strange one!

I think I would remove the grip, then go through the steps to reset the camera to the factory defaults (including clearing the custom functions). Then retest the "bare" camera and if everything appears normal remount the grip and retest.

Two thoughts. Clean all the contacts on the batteries and battery tray, inside and outside the grip, and inside the camera. Is it a Canon grip?