Ls400 Stock Pioneer Radio Troubleshooting

[kratbomc]

SOS. Help!! Any advice from the Lexus gurus???

The stock Pioneer radio for my 1990 LS400 is not working. I bought a replacement on eBay and swapped it in but to no avail. Same symptoms... The power is on because the display lights and it tunes to a station but there is no sound. Below is more symptom history and details.

How do go about determining whether it's a) both radio heads are bust, B) the amplifier is kaput (and by the way, where is the amp?), maybe c) an absent security code is keeping my radio from working, or d) none of the above.

The history of failure: First, I had to coax the radio on occasionally by pressing the on button repeatedly before it would go on. Then it would go on after repeatedly pressing the on button but the volume was faint, almost inaudible. Now nothing except the display light witht he tuner showing a legitimate signal station.

Thanks!!!