pc engine purple screen

I installed an rgb amp on a pc engine, but when I power it there is no signal on the screen. My turbo everdrive's led blinks as normal though.
I power it off, double check everything but nothing seems to be odd. Again no signal on tv.
I hook my composite cables via the external port, and all I get now is a purple screen. The everdrive blinks red once.
Unfortunately I don't have another game to test.
Before the rgb attemp, the machine was running fine with composite.
Have I fried my my pce?

 

Is it a PC Engine or Core Grafx? A connection on the flat cable between the two boards could have broken from bending it back and forth.

 

yes it's a pc engine. I think I may have stretched the flat cable a little when I was installing the amp. I'll try to open it up one more time when my frustration goes away..

 

If you opened your unit many times it's possible that you severed one of the wires which connect the two boards.