LEXUS SC400 radio problem

I have a 1993 Lexus SC400 with a REALLY strange radio problem no one has been able to diagnose. For about 6 months the power would not come on the radio in the mornings on my commute to work (no antenna, CD or radio). When I went out to lunch in the afternoon or on the way home it alwyas came on fine? Then it stopped coming on anytime of the day with the exception of once every month or so and then it would come on briefly and then cut off. When it is dark you can see that the display is flickering on and off but still no power coming on. If it wasn’t such a GREAT radio and so expensive to replace I would just get a new one. It has the NAkamichi that came in the car originally. Any ideas?? The silence is killing me!

If “nobody can diagnose it”, you are taking it to the wrong shop. It’s either not getting power intermittently due to a bad connection, faulty feed wire/fuse, or it’s getting power and has a bad ground.
If both of these check out, then it’s in the head unit itself. If you are emotionally attached to it, it can be sent off for repair (probably not the most cost-effective solution, though).
There are plenty of aftermarket units that are superior to your stock unit for far less money. I’d upgrade it if it was mine.

Have you thought about looking on ebay for a used unit?

The connection trouble may be internal to the radio. After you verify that you can remove the radio and send it in to have the unit repaired at a shop like this.

How would I verify that it is an internal problem and is the radio very difficult to remove? Thanks for your help!!