JuanUp
Active member
OK, I've been tackling this for too long now. I'm not making much progress but I've narrowed it down to why my Stargate won't boot up. I ordered the deluxe Bob Roberts Williams Power Supply, replaced practically everything and still nothing. Also, I've checked and cleaned all of the connectors, pins and fuses. The only components I haven't replaced are the TO92's and the TO220's, (not including the resistors and diodes which checked OK). I realized as I was driving home that I should of checked the voltages off the transformer as well. EDIT: I believe these are 2 MPSA55 and 2 C122A respectively. This is from the D-8784 power supply that I reading from Sinistar and Moon Patrol schematics. It looks like there are tons of test points I can read off of to isolate this problem. Something to check tonight. Gee, woulda' helped to have this available when I was working on it. 
Anyway, off the power supply (4J2) to the decoder / RAM board I'm getting:
1: -5.1 (-5)
4: -13.7 (-12)
6: 10.57 (+12) <-- problem voltage
12: 4.97 (+5)
13: 4.97 (+5)
14: 4.97 (+5)
These numbers are pretty much the same after I replaced most of the components.
Also, there was a 2N6059 (top) and a 2N3055 (bottom) that came in the kit which I installed on the heat sink. EDIT: Verified.
Another note is that the 2N3055 was bad when I tested it. Could this of fried the RAM? If so, is there a way to test them? EDIT: No, they weren't.
One other thing, is there a schematic of this newer power supply? I believe the Stargate drawing set I finding only has the older power supply. EDIT: OK, it looks like the Sinistar and Moon Patrol has the newer power supply schematics.
Again, I'll check voltages off the transformer tomorrow morning. Any help would be great and please correct me if I'm wrong on anything. I'm new to all this but I've been reading other posts related to this before I posted.
Thanks,
Juan
Anyway, off the power supply (4J2) to the decoder / RAM board I'm getting:
1: -5.1 (-5)
4: -13.7 (-12)
6: 10.57 (+12) <-- problem voltage
12: 4.97 (+5)
13: 4.97 (+5)
14: 4.97 (+5)
These numbers are pretty much the same after I replaced most of the components.
Also, there was a 2N6059 (top) and a 2N3055 (bottom) that came in the kit which I installed on the heat sink. EDIT: Verified.
Another note is that the 2N3055 was bad when I tested it. Could this of fried the RAM? If so, is there a way to test them? EDIT: No, they weren't.
One other thing, is there a schematic of this newer power supply? I believe the Stargate drawing set I finding only has the older power supply. EDIT: OK, it looks like the Sinistar and Moon Patrol has the newer power supply schematics.
Again, I'll check voltages off the transformer tomorrow morning. Any help would be great and please correct me if I'm wrong on anything. I'm new to all this but I've been reading other posts related to this before I posted.
Thanks,
Juan
Attachments
Last edited:
