The radio broke down a long time ago, but the problem will not show up until memory power is removed as in replacing the battery. If you have the cassette model 56038518 or the cd model that ends with "67", these are built by Chrysler with a microprocessor built by North American Philips, (NAP), the same people who build the really crappy Magnavox and Philips tvs. All microprocessors in all electronic equipment have a "reset" circuit that sets the millions of transistors to their starting point, (on or off), rather than letting them start from some jumbled random state. That reset circuit only operates for a few milliseconds when power is first applied. After that, it's job is done and it will not operate again until the next time the radio is unplugged, the battery is disconnected or run dead, or the interior lights fuse is replaced. That fuse is the memory circuit for the radio. Once the radio is up and running, that reset circuit can fail and you will never know it.
The most common problem is the three yellow leds in the tone controls blink about once per second and you hear a thump in the speakers at the same time. There is a list of about a dozen other things that go wrong, all related to the microprocessor. Some radios go dead for five seconds after moving the volume control. On some the sound will quit when you move a tone control and won't come back until you turn the radio off and back on. Sometimes the stations won't change when you try to tune to a new one. This mostly affects the radios with the three lighted tone controls but there are some models with two non-lighted tone controls that are also affected.
A lot of mechanics are falsely accused of damaging these radios because the problem shows up right after they performed any service that requires the battery to be disconnected.
There are two models built by Mitsubishi that are direct replacements and are real high quality. They look the same, mount the same, have the same lighted tone controls, and will run the same remote cd changer if you have one. The cassette model has one extra button for "scan". These radios weigh about three times more than the Chrysler-built models. They were only used for one year in only a few car models so they're kind of hard to find. They are in demand by used car dealers to replace non-working radios in their cars. I have some of all three, the cassette model, cd model, and the combo units.
Friday, February 25th, 2011 AT 11:08 AM