I have no history on the radio. With regards amp is there an easy way to check it? I have replaced the fuse and checkeda the contacts and amp looks good. No i dont see anything at the moment. I am using a cheap power supply which only just powers up another radio i have so wondering if i need to spend some money on a small workshop dc power supply. I am aware of the shop you mention I was just hoping it would be relatively easy fix.
It might be a relatively easy fix. When you say you don't see anything at the moment, do you mean when you turn on the radio you get no light? If you have an ohm meter / volt meter you will want to test the voltage at the base of the bulb and see if you are getting power there.
If easy to do so, add pics of the back of the radio and of the connection to the amplifier. I don't remember how much current that radio draws but if it's too much I would expect the power supply to flip off rather than do nothing. If there is an inline fuse in the black wire power cable then the amperage of the fuse might tell you (if it's the right fuse) and if your power supply is lots less than that you might need a better power supply. Or use a 12 volt battery but use a fuse with that.
The back of the radio should have a black wire coming out. And a big grey cable with another black wire going into the grey cable. The cable plugs into the amp and there should be a black wire coming out at the amp side of the cable with a slide-on connector. On the amp next to the plug there is a grounding terminal to slide the black ground connector to. The first black wire (opposite the grey cable usually) just gets 12V+ sent to it. Then you have to ground the radio to the negative of your power supply. Next you need to connect an antenna. You can get no or little sound if you don't have an antenna. I have a cheap antenna that I keep with my test stuff for this purpose. Then you need speakers plugged into the amp.
So is that your test configuration? If it isn't, then I would not worry about the circuit board at this point in time.
The only way I know of to test an amp is to test it with a known good radio.