Ideal 5v power supply level for JAMMA setup

[Tornadoboy]

I'm putting a new power supply in my JAMMA cab and I was wonder, what's the best level the 5VDC should be set at that's safe and nominal for most JAMMA boards? 5.2v? I ask because lately I've seen how touchy some games are if it isn't set high enough.

 

[security0001]

i always set them to 5.05 to 5.10vdc measured at the ttl chips on the game pcb

 

[parism]

I would set it at exactly 5.0V measured with a load on (ie pcb attached). Better to measure on the pcb itself, any TTL IC will do (5V and GND pins).

If a board needs higher voltage it could be an issue with wiring that causes voltage drops to the pcb, hence you need to compensate by upping the PSU voltage.

Make sure your power and Gnd wiring is of adequate gauge. Some JAMMA harnesses (ones found on eBay) have thick power wires but in most cases they are just thick insulation. Also, some of them only have one or two wires going to the 4 pins of GND and 5V. You should have a single wire attached to each power pin on the JAMMA edge connector.

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[Alpha-tron]

Just a note on measuring 5 volts off of the chip.

With a nice clean pcb and nice clean jamma connector. You can ignore what I am pointing out.

A dirty connector or and a dirty pcb edge connector. You might want to clean both before adjusting the power supply. Dirt and corrosion increases resistance with causes heat and will weaken pins and even burn the edge of the pcb.