No power to stereo, 91 chevy caprice

This might take a minute to relate, so I will start with my specs and troubleshooting so far:

Installing on a 91 chevy caprice classic a sony cdx-gt11w but the deck seems to get no power.

-only ground, power and acc are connected, but connections are good (verified with someone smarter than myself.

-fuse in deck and in fuse box checked (good) and replaced with new (just to be sure.)

-power supply has been checked by a friend (voltage meter checker) and is good; from the car, from the aftermarket harness and even through the wire harness of the radio itself.

-No reset button present or mentioned in manuals.

-No observation or mention of "packing" screw that needs to be removed before installation.

-Deck will not power on

The long story (/shrug maybe there be a clue in here somewhere.)

After fiddling with my jvc cd/radio (taking it out, inspecting, putting it back in a few times.) I decided I was done (Was looking for an aux port.) and started to put the deck back in the car. The car was on and suddenly the power to the radio went out. Fuse I thought. Checked and the fuse was fine. Great, I killed my radio.
So I go to wally world and get a 30 cassete player with an aux jack. Hook up the red power and ground lines and get power. No prob, I only wanted an aux line, 30 bucks no biggy. But the deck was for a truck and the rear speaker set up was with rca cables. I decided that was more than my simpleness wanted to handel so I went and got the next more expense deck for 50 bucks. A cd player with no aux port. Hook it all up, speakers included and nothing. No power. Check fuses in deck and car, all seem good. Switched some around just to be sure. Nothing. Great, of all the luck I got a 1 in 1000 defected radio. Go to replace.
Bought a 80 dollar sony (mentioned above) with an aux jack. Connected power, acc and ground.....nothing.

Why did the tape player get power? Why won't any other deck? What in the world is my problem?

Any help greatly appreciated

I'd recommend temporarily hooking the deck up straight to the battery to see if it's a wiring problem. It's highly unlikely all those decks refuse to turn on. Meter the battery voltage (that could be the problem) first. Then connect the red and yellow wires to the positive battery terminal, and the black wire to the negative terminal. Do the units now turn on? If so, there's a wiring issue that needs to be dealt with.

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My ex once told me I have a perfect face for radio.