My friend has a 1990 Cadillac Brougham with the AM/FM cassette radio. He's owned it for about 6 years and the radio was broken when he got it. It does not power on at all and he said the fuse is good. I understand that this is a two piece setup and the unit in the dash is the "head unit." There is a second piece under the dash. Anyone have any experience with these?
That is correct and the secondary section is buried in the dash and a nightmare to remove.
The part of the radio you see is just the control panel and tape transport mechanism. The actual radio itself ie: the tuner, preamp and power amplifier is that small box you cannot see.