I put this here in case someone else were to ever come upon this situation.
Although this happened to my 7DMkII and BG-E16 Grip, it applies to just about all cameras and all brands of grip.
The grip had been attached to the camera since November-2020.
This past Saturday, I was at an antique tractor/truck show and took about 1500 photos.
As the day progressed, I had a few occasions where I would press the shutter button and nothing would happen; I blamed this on possibly focus could not be achieved or maybe it was "busy" and didn't pay it much mind; as, within seconds, all was well and working as it should.
Then, at the very end of the day, as I was walking toward my truck to load up and leave, a friend came past me in his new-to-him road-tractor and trailer load of big farm tractors; it looked to me like a perfect photo opportunity, so I swung my camera into action --- and guess what --- dead as a doornail...
Not five minutes before, I had been snapping away.
My first thought was the batteries.
Besides a dozen other spares, I keep three loaded cartridges that fit the grip.
I tried another cartridge and still dead.
I put fresh batteries in the other two cartridges and one was dead and the other brought the camera into action; however, it did seem a bit sluggish to come to life.
Instead of being satisfied that I had it up and running, I tried one of the other cartridges and things went dead again; then, the one that just was working wouldn't work.
I kept switching and swapping around and got it working again and left well enough alone.
I went to classic Derby City Truck Stop for a real set down dinner where they treat you like a human, real live waitresses and all, and took a bunch of photos of the building, sign, and several non-Volvo trucks (I don't waste time with Volvos); the camera never missed a beat.
Later, back home, I undertook to get to the bottom of this going dead problem; and, after trying this and that, I couldn't get it to respond no matter what I tried.
Volt-meter in hand, I checked all the usual suspects and all seemed fine.
I removed the grip and tested for power at the battery contact points and all was good.
Put the grip back on the camera and it lit up for a few seconds and went dead again.
Aha !
I removed the grip again; and, those dozen or more spring-loaded brass contact pins at the very top of the grip stem, I pressed them down and let them snap back up numerous times, over and over and over again.
I put the grip back in the camera and she fired right up.
I switched cartridges and she fired right up again.
Tried the third cartridge and good to go.
Tried the first cartridge again and all is well.
So, the moral of this story is, if your gripped camera starts losing contact and intermittently or completely quits working, if you know for fact that the batteries are good, then remove the grip and work those connection pins in and out several times to re-establish electrical contact between the pins and the contact surface they slide within.
In this situation, the camera didn't exactly lose "power" as the connection to the batteries was fine; what happened was the camera lost communication with the grip due to those pins not making good clean contact.
I do have several cans of electrical contact cleaner; if this problem shows up again sooner than I think it should, I will give those pins a squirt of contact cleaner.
