Gauntlet Switching Power Supply Issues

Superully

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having restored my gauntlet (which was working fine before i started the resto), i put all the stuff back into the cabinet. i didn't connect monitor and pcbs to the power supply board though, just the a/c power cord. measured the voltages, everything turned out fine. connected both the pcbs and the monitor, turned the game on - BOOM! the F1 fuse directly after the filter on the power supply board AND the fuse inside the switcher were blown.

4975792587_55cc90c72b_z_d.jpg


since i couldn't find out what type of fuse (fast or slowblow) was used inside the switcher, i ordered both types. here's what i did when they arrived:

- i installed a fastblow fuse in the switcher first and replaced the blown one on the power supply board. turned on the game - BOOM! both the fuse directly behind the filter on the power supply board AND the fastblow fuse in the switcher blew!

- i replaced the fuse on the power supply board and removed the blown fuse from the switcher, turned on the game, steady output of around 120 volts to both the monitor and the switcher!

- i installed a slowblow fuse in the switcher next. turned on the game - BOOM! only the fuse directly behind the filter on the power supply board blew, slowblow fuse in the switcher is still ok!

summary: with all the cables removed, power supply WITHOUT a fuse in the switcher is working fine, as soon as i install any type of fuse in the switcher, the fuse on the power supply boards blows!

this sounds like the switcher is having some issues, but i'm pretty sure all the voltages BEFORE the first blowout were fine when all the connectors were removed. now i can't even reach that status anymore. all it does is blowing fuses ...

i need some input, guys! thx
 
When you had the switcher out, you didn't accidently reverse the black and white AC power wires (AC hot and AC neutral) on the switchers terminal strip did you?
 
When you had the switcher out, you didn't accidently reverse the black and white AC power wires (AC hot and AC neutral) on the switchers terminal strip did you?

you mean whether i mixed up the black and white wires on the switcher directly? nope, i didn't, because although i had the power supply board out entirely, i took reference pictures before and after cleaning it - and those match up!

BEFORE:

4993466224_0f11e66c11_z_d.jpg


AFTER:

4992859307_94cea30129_z_d.jpg


looks identical to me. PLUS as i've said before: when i reinstalled everything, the outputs were fine (i think!) with everything disconnected first, but then when i plugged the pcbs and the monitor in, the fuses blew. now the fuses blow even with everything removed ... :(
 
Does this game have a fluorescent light for the marquee? If so, do the fuses blow with the light fixture unhooked? If so, then there might be a problem with the switcher supply.

The factory switching regulator power supply can be replaced with a common Peter chou type screw terminal power supply. The "- sense" goes to ground (com) terminal and the "+ sense" goes to the +5 volts terminal.
 
Does this game have a fluorescent light for the marquee? If so, do the fuses blow with the light fixture unhooked? If so, then there might be a problem with the switcher supply.

no, it doesn't! coin door lights come on nicely though.

The factory switching regulator power supply can be replaced with a common Peter chou type screw terminal power supply. The "- sense" goes to ground (com) terminal and the "+ sense" goes to the +5 volts terminal.

what is a peter chou type screw terminal power supply? are those the normal switchers?

here's how the gauntlet switcher is wired atm:

4973515351_4449d494c7_z_d.jpg


from top to bottom:

AC1 (black wire)
AC2 (white)
FG
- (brown)
-S (brown-white)
+ (red)
+S (red-white)
NC

the spare switcher i have give me the following connections: -5V, +5V, +12V, GND, GND and AC1&2.

how would i have to connect the brown / red / brown-white / red white wires there?
 
Omit the sense connections...

They are feedback lines for the switcher to keep +5 at +5. Most new switchers have a manual adjustment pot instead of the auto feedback. So the sense lines are not really needed... connect the new switcher and adjust your +5 so it measures +5 on the board... you should be good to go.

My APB has the same switcher design and it was missing the switcher and this is the method I used when replacing the power suplpy.... works fine.
 
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so you're saying simply connect the brown wire to -5V and the red wire to +5V? should i then connect the red-white and brown-white wires to ground or just leave them dangling?

+S (red-white) and -S (brown-white) do not need to be connected to anything.
+ (reds) to be connected to +5 on new switcher
- (browns) to be connected to GND on new switcher.

Don't let the +S and -S touch anything as they are effectively across your +5 on your board.... just remove them from the molex connector on the PSU side. As Ken stated you can connect the +S to the +5 and -S to GND... either way will work.
 
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here's an update: i've setup the switchers as suggested and after some adjustment the output is steady at +5.02V. +/- 15V is a little bit high/low at +/- 15.42V - is that within tolerance levels?

i've reconnected all the wiring, no ore blown fuses, but no reaction from the game pcb as well - the baord LED stays off :(. monitor produces a simple grey picture because it isn't getting anything from the board. DAMN!!!

what would you test now? what could be shot? as i've said, the coin door lights are working nicely, the are powered "through" the audio pcb, so i guess this should be ok!

and now?
 
ok, i'll answer that myself! ;)

since i couldn't get the game to run with a normal switching power supply, i went on the lookout for a replacement and and i was lucky enough to find an original +/- sense version!
i quickly installed it and tested it for voltages. the time had come to turn on the machine and see what happens: i flicked the power switch, pcb led came on, i slowly walked around the cab to the front and ...

5029863814_84d935c5da_b_d.jpg


VOILA!!! :)

as you can see, there are some graphic issues on the title screen - none of which appear during gameplay or on the other attract mode screens. it really is only on the title screen! voltages on the pcb are steady at 5 volts, so it can't be an issue of too high or low voltages.

one more thing came up: i also found a coin counter, which was missing on my gauntlet. quickly installed it and gave it a test: you can hear the clicking sounds of the meter, but the display doesn't increment a bit, it stays steady at 35400. you can also see that the counter is trying to move one number up, but somehow it fails to do so. could this be a mailfunction of the meter itself or isn't it getting enough power?

5032641199_8963529304_z_d.jpg
 
Make sure the meter is the same voltage as the original. Some meters have an internal diode and some require an external diode or else the meter driver circuit can be damaged.

Doesn't this game use a 6 volt meter?
 
Doesn't this game use a 6 volt meter?

no idea, the meter was pulled from a gauntlet machine which uses exactly the same setup as mine. here's a picture of the meter before it was pulled from the cab. i attached it to the same two pins on the right.

5032747663_aa45fda1b8_z_d.jpg


as i've said before: it's clicking and it's trying to increase the number (you can see the movement), but it doesn't "flick over"!

any suggestions?
 
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