Can I use one of the GND and 5v pins on the Jamma interface?

OldFoo · Post by **OldFoo** » Wed Jan 30, 2008 6:57 pm

I am using JRocks RGB to NTSC converter. The power requires 2 connections. 5v and GND. I planned on using the pins 2 and 3 on the Jamma interface for these connections. But, then I read the Schematic. It says only use the connections described: Video Outs/Switch Inputs/Switch Ground Returns/Coin Counter Output.

Looks like Pin 2 is sending out 5V though. Any thoughts?

OldFoo · Post by **OldFoo** » Wed Jan 30, 2008 7:20 pm

you can use pins 1 and 2 for ground

pins 3 and 4 for +5v

you sure you have not reversed your meter leads whilst reading pin 2?

OldFoo · Post by **OldFoo** » Wed Jan 30, 2008 7:32 pm

I am doing a continuity test from the GND on the Power Cable that plugs into the wall. Doesn't seem like anything is grounded on my Sega I/O (Jamma) board when testing this way. How should I test for this?

OldFoo · Post by **OldFoo** » Wed Jan 30, 2008 7:55 pm

set your meter to dc volts 20 volt range,then place the black probe in com socket on the meter and the red probe in the ac/dc volts socket

power up the cab then place the black probe to pin1 on the jamma and the red probe to pin 3 on the jamma-should get above 5.05 volts dc

the reason you are not getting continuity is because ground after the psu is not the same as earth which is in your wall socket

OldFoo · Post by **OldFoo** » Wed Jan 30, 2008 8:36 pm

Excellent. I did as you said... looks good. Soldered and tested.... all systems go! Thanks

OldFoo · Post by **OldFoo** » Wed Jan 30, 2008 9:04 pm

:smt023