Sega-Naomi

UPDATED POST



Hey guys,



I've been using my Jamma cabinet for a few years now, without issue.



I've plugged in different pcbs, etc, and never had any real trouble.



I've played with my CPS2 system on many occasions, switching out A boards whenever. Again, never any trouble.



I recently made some shelves in the back of my cabinet, so that I could put more than one system in the cabinet, and just disconnect the Jamma harness and swtich to another pcb or system whenever I wanted.



Again, worked fine.



The problem was, the cable for the Jamma harness wasn't very long, so it was always tight to reach the pcb or system or whatever.



SO, I bought a Jamma extension harness from JammaBoards.com. Seemed to be well made, so I plugged it in.



Turned on the cabinet, and started playing.



Everything seemed fine, then I heard a small pop, and the sound and picture went out. Power to the cabinet was still on, the monitor and lights were still working.



So, I went to the back of the machine, and could smell a faint burning smell. The A board was no longer working.



I originally thought that something was wrong with the CPS2 A board, but I opened it up, and don't see any damage or anything.



So, I dedided to remove the JAMMA extension harness, just in case that had something to do with it.



Before I connected anything, I turned on the cabinet. The marquee light worked just fine. The monitor has power, because I can see a picture (of sorts.)



Turned it off, and connected an STV board, and turned it on. Nothing. No picture, no sound, no light on the board.



Tried with a different board, and again, got nothing.



I checked all of the connections, fine. Took out the AC transformer fuses to see if they were blown - not blown.



I'm afraid I've reached the end of my limited technical knowledge.



Can anyone give me some help with this? I don't know what else to do.



I truly appreciate as much help as possible. I'm basically a noob, so please use terms that don't need an electrical engineer to decipher.



Thanks!



Steve[/b]

No idea.



Why don't you pull the CPS board stack out, disassemble it, and find what is in pieces?

Can anyone help, please?



I'm not as concerned about the CPS2 A board, just if the cable or power from the cabinet was responsible.



I don't want to ruin anymore of my hardware.



How can I find out?



Thanks,

Steve

Updated post - bump.



Really could use some help.

To diagnose an electrical problem, you need a volt-meter to check supply levels and continuity. Until you do that, switching pcb's won't help. Once you have one, then you can be instructed on what to do next.

i think that your cab power supply is at fault,i believe that the extension cable you got is either wrong or the strain of the extra wiring just pulled a little too much current and popped the psu

of course to prove would take 10 seconds if you had a multimeter as you need to do is read the +5 and +12

go get a multimeter at walmart or where ever for a few dollars then check back here and we can walk you through using it

this is the one most valuable tool you can own

grantspain wrote:I think that your cab power supply is at fault,I believe that the extension cable you got is either wrong or the strain of the extra wiring just pulled a little too much current and popped the psu

of course to prove would take 10 seconds if you had a multimeter as you need to do is read the +5 and +12

go get a multimeter at walmart or where ever for a few dollars then check back here and we can walk you through using it

this is the one most valuable tool you can own

Thanks guys - I'll do just that, and see if I can get a reading.



Steve

on the multimeter

put the red probe in Vdc socket and the black probe to ground

set the multimeter to a range of 20volts on the dc part of the dial





on the jamma connector

place the black meter probe to pin 1 or 2 and the red to pin 3 or 4,this should give you a +5volts reading of around 5.0 to 5.1



you do not need to plug a board in to read the +5 but be advised as there will be no load the reading will be higher than if you did have a board plugged-this is only to prove you have +5 safely and without risk to another game board(however unlikely)

Ok. What about the 12v line?

grantspain wrote:on the multimeter

put the red probe in Vdc socket and the black probe to ground

set the multimeter to a range of 20volts on the dc part of the dial





on the jamma connector

place the black meter probe to pin 1 or 2 and the red to pin 3 or 4,this should give you a +5volts reading of around 5.0 to 5.1



you do not need to plug a board in to read the +5 but be advised as there will be no load the reading will be higher than if you did have a board plugged-this is only to prove you have +5 safely and without risk to another game board(however unlikely)

Okay, when I said I'm clueless, I really meant it. I can pick up things once I've done it, but I'm definitely new to this.



Here's a pic of the multimeter that I got:







I don't know how to use it. I'm not sure which hole (1, 2, 3, or 4, from left to right, that the red or the black leads should be connected to.



After that, I'm not sure how to use it.



Here's a pic of my PSU:







If you wouldn't mind letting me know what to connect what to what, in order to check, I'd appreciate it.



Sorry to ask for the children's instructions, but I'll need it this first time.



Thanks so much for your help guys - you're awesome!