Bose Speaker Amps/radio face

[Schrade]

Originally Posted by LancePearson

a diagram service sent me the system diagram schematics today so I'll pass it along. It does not go inside the boards but is a fairly clear presentation of the system as I see it.Attachment 2228

I got board schematics there Lance, for the mainboard, and for the tape/CD board from Bob carstereohelp.com.

Your lights don't go through the board. Only way to check the missing incandescant bulbs is to pull them, and check the bulb filament for continuity, then check the Incand input (the solid gray input on the smaller HU connector), TO the first bulb socket, then the second (I don't know if the bulbs are in series, or in parallel). ON SECOND THOUGHT; THE FSM NOTE TO THE RIGHT SAYS NOT TO MEASURE IMPEDANCE TO THE UNIT - I DON'T KNOW IF YOU CAN ISOLATE THE INCAND CIRCUIT THROUGH THE HU

(in the 2 schematics, board header ID's P701 and P702 correspond to CN101, and CN102, respectively, to our HU header ID's.

Never mind my notes there; that's for the AUX Input mod...

The gray input