[ RadSafe ] Davidson model 2056-4K-A MCA

[elam24]

Hello,

I recently repaired my MCA  2056-4K-A and know little about it construction,
Probably you problem locate in DC/DC power supply:  that is:  missing +5V 
voltage.

First You should check  voltages on supply connector :

10 pin conector :

pin No.  wire colour   voltage              comment
1             WHT            depend charge or not             from charger
2             GRY              ca 12v               from battery
3             PUR              +12V                    DC/DC stabilised
4             ORG               +5V                     DC/DC stabilised 
Logic supply
5            BLK                0V                        GND
6             BLU               -12V                     DC/DC stabilised
7            YEL                ca +12V                  non stabilised  CRT 
Display supply
8              BRN               0V  GND
9              BRN               0V  GND
10            BRN               0V  GND

( measure DVM between appropriate pin and pin No 5 (BLK  GND)

If you have any question plese ask me on elam24 at wp.pl

Im also interested on manual to this MCA could You send me a copy ??

Im sorry for my poor english.

Rafal