Dodonpachi dai ou jou...weird problem
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moonwhistle
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Is this PS2 or PCB you're speaking of?
stuffmonger
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I'm pretty sure that neither a pcb OR a cd is meant to reset a couple of times before working properly... mayhaps you have a dirty connection or something along those lines.
I'll let you know if it happens again...strange.
ttooddddyy
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Is the 5 volts at the edge connect OK, if low it may cause this sort of problem.
John_Smith
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ttooddddyy said:
Hey Toddy, I tend to test and adjust my 5v supply at the edge connector on my supergun while no PCB is plugged in, though I've noticed that if I check it with a PCB connected and powered it reads much less at the tabs in the jamma connector on the PCB. I'm talkin' 4.3v and the like! Is this normal or should I not get this much drop off from a full 5v?
Cheers mate!
John_Smith
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MKL said:
Ah okay cool, thanks for that MKL!!
ttooddddyy
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As MKL said
With the load (board set) connected there will be current drained from the power supply resulting in voltage drop in the wireing harness, as the wires have a resistance.
So it is important to set the + 5 volts whilst measuring at the jamma edge connect, or preferably on the actual game board.
Some boards draw more current that others (resulting in more voltage drop in the harness) so its worth checking every time you swap boards. I usually set mine to just a whisker over 5 volts. I wouldnt set it to anything above say 5.2 volts.
With the load (board set) connected there will be current drained from the power supply resulting in voltage drop in the wireing harness, as the wires have a resistance.
So it is important to set the + 5 volts whilst measuring at the jamma edge connect, or preferably on the actual game board.
Some boards draw more current that others (resulting in more voltage drop in the harness) so its worth checking every time you swap boards. I usually set mine to just a whisker over 5 volts. I wouldnt set it to anything above say 5.2 volts.
John_Smith
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ttooddddyy said:
Okay now we're getting somewhere!! To lay it all down for you I've had an emerging power issue which I couldn't for the life of me work out and the last couple of posts have shed some light on it now. My arcade PSU has a overload cut-out function and as I've been tweaking the Vcc pot while monitoring the voltage at the 'under load' PCB edge connector, I've hit its limit and it will cut out and I have to reset it. So I'm thinking, that's freaking great, maybe my PSU's on the way out.
Next -
I'm only getting say 4.7v max under load before cut-out at the edge connector, so then I decided to check it at the PSU it's nearly 6v!! I am using some nice heavy professional 4 core microphone cable to run the voltage from the PSU to the supergun, two metres (nearly 7") in all and I guess it's adding a lot more resistance than I thought it would. Do I need to go heavier or lighter on the gauge of wiring to reduce the resitence? (Probaly sounds like a silly question I guess
). Oh, one other thing, I've only got the one GND wire of the four cores in this cabling, perhaps I need a more capable GND run? Maybe a four core with shielding brade to use in addition for better grounding?? 
ttooddddyy
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The heavier duty the cable the better, and as short as is practical. Certainly using more than the one ground will reduce the voltage drop.
a correction on terminology, when I said current drained, meant current drawn.
a correction on terminology, when I said current drained, meant current drawn.
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There is also a little switch on the PCB nicknamed "the Devils switch" if it gets touched it causes all kinds of fuck up in the games, (my ketsui did it for a while)
Try going into the test menu and setting the dips to default, that might do it.
Try going into the test menu and setting the dips to default, that might do it.
John_Smith
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ttooddddyy said:The heavier duty the cable the better, and as short as is practical. Certainly using more than the one ground will reduce the voltage drop.
a correction on terminology, when I said current drained, meant current drawn.
Firstly I'd like to apologise to Zak for running off on such a tangent from his original subject, I'm kinda confused as to how that happened actually…
But, just to add some more salt to the gaping wound, I wanted to offer some closure on my power related issue. After reworking cables and optimising to the enth degree, my issue turned out to be the result of a worn out power switch on my gun!!! It's the last thing I would have suspected as it's a real heavy duty AC voltage toggle switch with 4 terminals and 2 positions. But, after swapping it for a new one much the same, but a little more robust on its max current ratings, it’s just like the first time I fired the gun up all over again!!! Tis still confusing though as this model switch is typically used in 110 - 250 Volts AC applications. Anyway, all's well that ends well I always say.
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Wow that thing even came up at all at 4.3? CPS2 games won't even spin the fan at that setting Yeah, up the +5 on that puppy. As for the power drain... seen it on a 4 slot, ended up surging as I was playing with the PSU and killed a few carts 
Yeah, up the +5 on that puppy. As for the power drain... seen it on a 4 slot, ended up surging as I was playing with the PSU and killed a few carts John_Smith
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nruva said:Wow that thing even came up at all at 4.3? CPS2 games won't even spin the fan at that setting
Ouch that sucks! I didn't realise you could damage carts through over voltage; I figured something else would have given out first. Nasty!
I cracked open the offending switch and although not immediately evident there was some small burn marks where the little pivoting contacts touch the top of the inner terminals. I scraped em back a little with a small screwdriver and there was some pitting as a result of the constant minor arcing as the switch was used. I guess like anything they just don't last for ever, routine maintenance has to be expected. We'll its good to know that I've gleaned some real mileage out of my supergun thus far, makes it all worthwhile.
ttooddddyy
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relatively high current does that to switch contacts
also with dc there is a switch arc which can be reduced with a reversed bias diode.
Im suprised it happened to your set up
also with dc there is a switch arc which can be reduced with a reversed bias diode.
Im suprised it happened to your set up
Lime2K
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nruva said:Wow that thing even came up at all at 4.3? CPS2 games won't even spin the fan at that setting
Yeah, but the fan in a CPS2 board is running off the 12V line, not the 5V. I just had ro replace the one in my board, 'cause it sounded like a dentist's drill (WEEEEEEEEEEEEEEEEEEEE...). It's much quieter now.
John_Smith
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Yeah, I gotta admit, they are crazy loud! I've been meaning to replace the fans in my 'A' boards with quieter ones for a while now. They get pretty intolerable, almost enough to act as a deterrent to play CPS-2 over something else in the collection!! 
And toddy, does this diode you speak of somehow lessen the shunt on the contacts or something? I’d love to hear more on that, as it sounds like I could get some more life out of the switches that way!
The arc burns weren’t that bad, but obviously enough cause the contacts to fail when put under load. Larger PCB’s just wouldn’t even fire up after a while and even smaller, less amp hungry boards would be problematic.
And toddy, does this diode you speak of somehow lessen the shunt on the contacts or something? I’d love to hear more on that, as it sounds like I could get some more life out of the switches that way!
The arc burns weren’t that bad, but obviously enough cause the contacts to fail when put under load. Larger PCB’s just wouldn’t even fire up after a while and even smaller, less amp hungry boards would be problematic.
ttooddddyy
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John_Smith said:
This is to do with relay contacts and mainly to do with DC switching, there is some info on AC switching also (resistor-capacitor snubber circuits), which may be of some help.
http://www.leachintl2.com/english/english2/vol6/properties/00049.html