I am hoping to get additional direction before I plunk down the cash for a new transformer. I've been chasing this ghost on and off for better than a month. The original problem resulted in having to replace the power driver board. After I put the new board in and replaced all the Molex connectors that connected to the new board, the pin would randomly reboot after a couple minutes of play. I figured out that I had a GI problem. The machine behaves perfectly normal if I disconnect the connector going to J115, which is traces back entirely to the GI circuit off the transformer. I thought it was the board or one of the outbound connections from the board (J119,120, & 121) but those all checked out fine.
I finally thought to check the voltage coming out of the transformer. I checked the continuity of each circuit back to the 9 pin connector on the transformer. I made my measurements of the GI yellow white circuit by disconnecting the 9 pin connector coming right off the transformer. Three of the pins are only putting out 4.2 volts (those that connect to white/brown, white/orange, & white/yellow) while the other four pins are only putting out 1.3 volts (yellow, brown, green, & orange). I thought this was supposed to be a parallel circuit (in the transformer) so they all should be putting the out same voltage(?)
According to be schematic all the connections on J 115 are supposed to be a 6.8 V. I figure unloaded i should probably be seeing greater than 7V on the circuit, not the oddball voltages I measured. (I also checked it with my oscilloscope and the signal is clean and steady, just really low voltage.)
Any thoughts about something else I could be missing? I would appreciate any feedback!
Clark, MO
