sega jvs-jamma thing ver 2

OldFoo · Post by **OldFoo** » Sat Jan 15, 2011 9:51 am

hi guys, i have just landed a sega jvs - jamma thing. i only have an egret2 to use just now so this seemed like a good idea. however.

does this power up from the jamma loom ???

how do i set a naomi 1 mobo to output at 15khz ???

i had a look and the thing i have is in the sticky for hardware. its the version 2 jvs - jamma adaptor.

would i need a different power supply for the gd rom ??? if so what voltage do i need ???

from what i see it looks like a simple plug in,but i thought i would check first. i will be going for my naomi games later.

should i be aware of anything ??? it will be getting fitted later today. im hoping its as easy as it looks. but any advice would be great.

cheers.

john bud

OldFoo · Post by **OldFoo** » Sat Jan 15, 2011 6:43 pm

right im back.

i set the dips to 1 up 2,3,4 down. plugged in the adaptor, connected it to the jamma connector and fired it up.

im getting the sega music that you usually get but, the screen is only showing 1 inch lines of garbled rubbish.

before i start retuning monitors etc is there anything i should try ???

it does seem to be outputting something onto the screen but as said only 1 inch bars across the horizontal.

any advice would be great, im choking to get back into my hokum.

cheers.

john bud

OldFoo · Post by **OldFoo** » Sat Jan 15, 2011 7:48 pm

Since the cab is JAMMA compatible, have you tried running a standard JAMMA game in the cab? Just to verify the cab/monitor is not defective.

DIP Switch 1 on the Naomi should be set to the 'ON' position to output 15khz, and in the 'OFF' position to output 31khz.

OldFoo · Post by **OldFoo** » Sun Jan 16, 2011 10:48 am

hi cageman, thanks for the reply.

the cab plays jamma games no problem at all. apart from 2 games raiden and raiden fighters. these might need the voltage adjusted slightly. i also run an f3 system through the cab again no probs at all.

i will get a meter out later today and check the voltage to the jamma connector. if need be i will adjust it.

i may also try to tune in the monitor, it does seem to have a picture of sorts.

thanks so far.

cheers.

john bud

OldFoo · Post by **OldFoo** » Sun Jan 16, 2011 11:54 am

just checked the voltage at the jamma connector, its sitting at 3.6v.

im now trying to find the pot to adjust the voltage, apparently its blue but i cant see it.

but why do my jamma games run at such a low voltage ???

i will try to get the voltage back up to 5.

cheers.

john bud

OldFoo · Post by **OldFoo** » Tue Jan 18, 2011 10:52 am

still no joy, ive got the voltage at 5.045v. im getting the naomi boot screen but i cant get a picture. the screen is vertical and showing about 6 screens all compressed. i cant stretch it out to 1. i have tried all combinations of dips but still no joy. im stumped. cheers.

john bud

OldFoo · Post by **OldFoo** » Sat Jan 22, 2011 11:31 am

still no joy with this thing, im starting to think its a sync problem, i will also replace the connecting cable just in case thats the fault.

cheers.

john bud

OldFoo · Post by **OldFoo** » Sat Jan 22, 2011 10:37 pm

I've a feeling it may be a sync problem , i recently tried using a Chihiro mobo in my AWSD with a capcom I/O and it wouldn't sync no matter what i did yet in another cab it would, nothing i did would change it either.

Naomi works no problem though, i think these converters can be a little temperamental depending on the cab/psu etc, is there anyone close to you who's cab you can try it in to see it is working properly?

OldFoo · Post by **OldFoo** » Sun Jan 23, 2011 9:37 am

i might take it to the sharkfactors and try it in his cab. either that or i will find a member on jamma+ with a woody. the cab im using is an egret2, although i dont think that should make any difference.

cheers.

john bud

OldFoo · Post by **OldFoo** » Sun Jan 23, 2011 9:38 am

i might take it to the sharkfactors and try it in his cab. either that or i will find a member on jamma+ with a woody. the cab im using is an egret2, although i dont think that should make any difference.

cheers.

john bud