Pengo w/Switcher

joseph77

Well-known member
Joined
Jan 3, 2009
Messages
2,150
Reaction score
115
Location
Cicero, New York
Does anyone have a close up picture of a Pengo with a switching power supply installed? I would like to install one in mine, can't seem to get it to work.
 
See the board schematic. Assuming this is the Pacman type board with AC inputs and onboard 5v regulator, jump 5 and 12v direct to the board where they should be. Might be a good idea to remove the 5v reg transistor from the board as well.
 
Just looked up the pinout for a Pengo board. Its pretty straight forward from the looks of things...

Pins 1/2/A/B - GND
Pins 3/4/5/C/D/E - +5
Pins 19/W - +12
 

Attachments

  • Screen Shot 2012-10-02 at 1.36.35 PM.jpg
    Screen Shot 2012-10-02 at 1.36.35 PM.jpg
    13 KB · Views: 23
So after doing some reading it looks like early Pengo's ran off of AC voltages not DC voltages. I'm assuming thats the board you have.

When I was fixing Pac boards I ran them off a DC switcher. ALL of the return wires were connected to the GND pin on the power supply. The 7VAC wires were connected to the +5 and the 14VAC wires were connected to the +12 on the supply. The trick is to CRANK the power supplies output so that you end up with +5VDC after the regulator on the Pengo board. Since the diodes on the Pengo board will now have nothing to do the board will also run cooler.

I've never seen an AC Pengo. Take a pic would ya?
 
I don't recommend this method. While it works fine for the 12v audio amp supply, you're running the 5v into the reg circuitry. The 5v from the pwr supply won't be high enough to get thru the regulator correctly. You'll end up with low 5v. Jump the 5v direct to the 5v rail on the board and you'll be ok.

The early Pengo boards were very similar to Moon Cresta, and that used the on board 5v reg circuit.

http://www.crazykong.com/pcbs/G - O/MoonCrestaSega.pcb.html
 
I don't recommend this method. While it works fine for the 12v audio amp supply, you're running the 5v into the reg circuitry. The 5v from the pwr supply won't be high enough to get thru the regulator correctly. You'll end up with low 5v. Jump the 5v direct to the 5v rail on the board and you'll be ok.

The early Pengo boards were very similar to Moon Cresta, and that used the on board 5v reg circuit.

http://www.crazykong.com/pcbs/G - O/MoonCrestaSega.pcb.html

On the surface that looks like the same +5 regulator circuit as Pac Man. I'm tallin ya, I did it for YEARS without any issue at all. As a matter of fact if I did have a board with a problem it had a bad +5 regulator and wouldn't have worked in an AC wired cab in the first place. Thats why I pointed out that the +5 should be turned up on the power supply. I even wired up MsPacs that were on the route this way. Long gone was the AC ripple, the bad edge connectors, bad fuse holders. And did I mention that the board runs cooler?

Its up to the guys asking... I know it works...

BTW, that Moon Cresta board looks a lot like a Galaxian board!
 
Pictures of my boards, not sure if they are a earlier board or a newer board?
 

Attachments

  • 100_1036.JPG
    100_1036.JPG
    93.8 KB · Views: 28
  • 100_1037.jpg
    100_1037.jpg
    96.7 KB · Views: 28
  • 100_1040.jpg
    100_1040.jpg
    98.9 KB · Views: 28
Pictures of my boards, not sure if they are a earlier board or a newer board?

Thats a DC Pengo. My earlier post with what wires go where on the switcher with the picture of the edge connector diagram will work.
 
On the surface that looks like the same +5 regulator circuit as Pac Man. I'm tallin ya, I did it for YEARS without any issue at all. As a matter of fact if I did have a board with a problem it had a bad +5 regulator and wouldn't have worked in an AC wired cab in the first place. Thats why I pointed out that the +5 should be turned up on the power supply. I even wired up MsPacs that were on the route this way. Long gone was the AC ripple, the bad edge connectors, bad fuse holders. And did I mention that the board runs cooler?

Its up to the guys asking... I know it works...

BTW, that Moon Cresta board looks a lot like a Galaxian board!

Yes it works just fine running dc straight through on the AC board. I have done it many, many times with pac and galaxian boards on my jamma rig. Before I upgraded my power supply I had a non adjustable supply and the boards ran solid at 4.7v at the chips. I have since changed the power supply so I can bump up the 5v but the only reason was because I was having issues with some nintendo boards. So yeah, no need to add jumpers or solder wires to the board when running an AC board with a switcher. Why hack the board up if you dont have to?
As far as hooking up a switcher to pengo it should be straight forward. Look at the pinout and hook it up. There's nothing trivial about it.

Pacman, galaxian, moon cresta, AC pengo, and AC frogger are all similar hardware. I think the power supply section is identical on the sega boards as the midway boards but its been a while since I have seen one.
 
Last edited:
I don't recommend this method. While it works fine for the 12v audio amp supply, you're running the 5v into the reg circuitry. The 5v from the pwr supply won't be high enough to get thru the regulator correctly. You'll end up with low 5v. Jump the 5v direct to the 5v rail on the board and you'll be ok.
Glad to see someone else thinks this is a poor method.
 
Glad to see someone else thinks this is a poor method.

Poor?? Why? Oh yeah, this is a mission critical computer on the space shuttle so it HAS to be perfect right?

The way I described adding a switcher to an AC powered Pac/Pengo DOES NOT require any modification of the board whatsoever. This means that the DC powered Pac board can be moved to an AC powered machine without any wires needing to be cut... WOW, thats friggin cool!

I've been adding switchers to Pac's since the mid 80's and It never failed to work. As a matter of fact while the AC powered Pac's kept coming back into the shop for various issues (bad edge connectors, bad caps on the board and fuse holders) the machines I modified to run with a switching power supply NEVER came back until the monitors failed.

Besides, all of this talk of an AC Pengo turns out to be for nothing. The OP has a DC Pengo so installing a switcher would be super easy.

EDIT: Never mind the statement about the OP's Pengo. We still dont know if his machine is AC or DC.


Ugh...
 
Hell I forgot all about this thread. I will have to pull the Pengo out and check.

Poor?? Why? Oh yeah, this is a mission critical computer on the space shuttle so it HAS to be perfect right?

The way I described adding a switcher to an AC powered Pac/Pengo DOES NOT require any modification of the board whatsoever. This means that the DC powered Pac board can be moved to an AC powered machine without any wires needing to be cut... WOW, thats friggin cool!

I've been adding switchers to Pac's since the mid 80's and It never failed to work. As a matter of fact while the AC powered Pac's kept coming back into the shop for various issues (bad edge connectors, bad caps on the board and fuse holders) the machines I modified to run with a switching power supply NEVER came back until the monitors failed.

Besides, all of this talk of an AC Pengo turns out to be for nothing. The OP has a DC Pengo so installing a switcher would be super easy.

EDIT: Never mind the statement about the OP's Pengo. We still dont know if his machine is AC or DC.


Ugh...
 
Back
Top Bottom