Naomi cutting off during gameplay

[Raph_friend]

It will short your Naomi and it won't work and there's some chance of damage.

 

[stj]

before you do anything more,
put a NEW battery in your multimeter and re-check the voltages.

a low battery will mess the readings up long before most meters tell you it's low!!

 

[war3zlod3r]

So whats it putting voltage out over pin 9 the naomi or the monitor? Who is the culprit here, right now I'm bypassing the VGA cable and using the JAMMA edge but the cable going from naomi to the capcom IO is also fully pinned.

 

[Raph_friend]

Capcom I/O PCB don't use VGA pin 9, other devices will use, like Extron RGB and may cause a short. You can open your devices and check yourself, will be better.

 

[stj]

the video source should provide 5v to the monitor.
the purpose is to power the DDC eeprom in the monitor so that the computer or whatever can read the monitor make/model/frequency range etc even if it's turned off.

 

[nem]

All of the Sega cabs I've seen come originally with cables that have the 9th pin pulled. I guess one of the monitor manufacturers didn't get the memo what pin 9 was for? Or maybe it was just as a precaution, I don't know. I haven't bothered to check all of them. I know the Tosh PF doesn't use it for anything (there's nothing connected to it).

Anyway, if you Google 'vga pinout' and look at image results, there's at least two pics in the first ten images that look like this:

 

[mathieulh]

ok so I've taken readings with my meter on both the JVS loom in the cab and the Capcom IO board and checked them again after putting everything on the supergun:

JVS Loom:
11.88v
5.32v
3.45v

Capcom IO power connector (farside):
11.87v
5.30v
3.27v

Capcom IO power connector (farside) connected to supergun:
12.16v
5.12v
3.27v

Please tell me if anyone sees something glaring here, is my Blast voltage too high?

Even off load your voltages on the JVS interface are way too high, you are literally killing your naomi board.

 

[mathieulh]

Ok so I retested and the numbers directly off the naomi are

on JVS loom:
11.57v
4.72v
3.04v

Supergun:
12.20v
4.96v
3.17v

When I tried testing off the capcom IO alone pluged into the JAMMA edge I was getting undervolting .2mv on the 5v line.
Oddly I noticed if I didn't plugin the monitor until after I heard the noami boot sound it would give me the gateway error because I didn't have a pi pluged in at the moment but assume it would have been ready to netboot. So I'm guessing I need to turn the voltage UP on the blast?

Something is very wrong, 4.72 on load when you started with 5.32 is way too much of a delta and should not happen, I suspect your PSU is low grade at least and has massive ripples, change it.

4.72 on load is way too low, I am surprised this system even boots, you need 5.00v minimum for naomi2 and 4.9V minimum for naomi1 for something stable.
your 3V line is also too low, you need 3.15v minimum on load.

 

[stj]

set the meter to AC volts and test again.
this will show the ripple.

 

[war3zlod3r]

set the meter to AC volts and test again.
this will show the ripple.

I'll give this a try when I get back to my machine, it seems stable so far but I can turn it up if thats what you guys recommend