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Looking for GM900 / MCS2000 service manual/schematic/PCB layout

Posted: Sun Mar 12, 2017 4:14 pm
by codefoxed
Hi folks,

Does anyone have a service manual which contains a parts list, circuit diagram and PCB layout for the last revision of the 10W UHF Closed Architecture Controller Board in a GM900?

The PCB carries identifying part numbers 05574X11, 258Y02 0, 8905566X04 A, 8905567X06 A, 8905568X05 0, 8905569X05 0, 8905570X03 0. On a label, it has the barcode UL1C-083244. It seems to have been built around 1996 based on the component date codes; the serial number bears this out (April 1996).

I have a schematic and layout for HUE4015B "PCB 8405574X07-T6", but this radio seems to differ in several key areas. I suspect it's a later board revision.

I suspect MCS2000 10W UHF may be similar -- there may even be a schematic or PCB layout in one of the MCS2000 manuals or updates.


I'm trying to track down an issue where the radio CPU locks up after being programmed with CPS. The Zeners on the accessory port test good, as do the transistors I've been able to test (some don't match my parts list).

I'd also be very grateful for a cross-reference from Motorola part numbers to semiconductor manufacturer / part number if such a thing exists. Finding pinouts for the transistors has been a case of trial and error, and I'm not 100% certain if I'm right about what these parts are.

Cheers,
Fox