Hi,

I have a GM car equipped with a Delco stereo. Recently the backlight
of the LCD display went out. Going to garage to replace the lamp would
likely have cost around $150, so I dismissed that right away . Did
not want to buy a new radio either -- the radio works fine, except for
the display.

So I took it apart. I was stunned. The design of the radio is such
that to replace a $0.15 lamp in the radio you really need to spend a
couple of hours (Hence $150). The lamp is hidden under under an LCD,
and to get to it the LCD needs to be unsoldered. LCD itself is under a
metal brace that also needs to be unsoldered. Not to mention that to
get to that point you have to deal with non-standard size screws etc.

So, I did all that and replaced the lamp with an array of LEDs. Now I
hope it will never fail.

Anyway, since I already opened it up, I decided to explore a
possibility of connecting an MP3 player to it (I only have a radio
).

Inside I see two big chips by Philips, one is obviously an FM/AM chip,
and the other is a DSP. I'm pretty confident that the DSP has extra
inputs to connect an MP3 player. It's too big a chip. But, I can't
find datasheets corresponding to either of the chips. For example, one
of the chips (DSP) has the following marking on it:

180431
09375033
DSD000402

searching either of them, and even parts of them does not produce any
results, nor in google, nor in usenet, nor on philips web-site.

I'm positive that these chips are not proprietary (much cheaper to use
stock chips), but rather are just privately marked stock chips.

So if anyone knows how to identify those chip, the help would be
appreciated.
----------------------
....After writing to this point I decided to look at the list of all
Philips audio chips. Turns out that they have only one AM/FM chip and
two DSP chips *in the same package* as in the Delco radio. The DSPs
are SAA7705 and SAA7706.

So I think this is it. I'll have to compare the datasheet to the
layout of the board to confirm that. Any feedback is still welcome
though.

Regards, S

Upon further investigation I came to a conclusion that these indeed
are prorietary chips. *******s, that makes connecting MP3 player
nearly impossible.

S