Ms Pacman #3428 not working and cleanup project

Mastecutor

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Well i had this unit shipped from Indy to Dallas Texas. The plan is to get it fully functional . Clean it up. Rebuild controllers, clean up coin mech . Clean up lighting. Update CRT chassis if needed. Cabinet, fan and main PCB.


At first visual :

1) Not sure if Tube is original? It appears Chassis is different as it is mounted awkwardly. It has a
Wells Gardner K4900 (4 pot) chassis.

2) lights are out

3) PCB was updated .No auxiliary board.

4) Exhaust Fan limping along. RPMs not what it used to be.

5) No picture on crt when powered up. :001_ssad:

Few pics
#3428
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IMG_9634.jpeg

Misc pics.
IMG_9605.jpeg IMG_9601.jpeg
123_1.jpeg

123_1.jpeg


Tube Chassis is wobbly and appears problematic if it shorts the bottom of pcb to mounting plate which is grounded. No more plugging into AC until this is fixed. Chassis appears it was halfheartedly retrofitted to crt chassis mounting plate.
IMG_9613.jpeg

:poop: WTH?!
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Fuse holders caught my attention. The monitor xfmer had a fuse holder that wad busted . Go figure after 45 years. Looking at schematic/block diagram it appears to be the 1 1/2A slow blow which is in the path of a 13VAC which feeds the control panel and coin door lights.


Original 3 pole slo blow fuse holder. 1.5A was busted. The 1.5A still appears to be shorted. But don't be fooled. Measuring a fuse in circuit in this position can be mistakenly measured as good when it is not.

( 1x1.5A and 2x 2A) 6mm x 30mm. All Slow blo.
IMG_9625.jpegIMG_9633.jpeg

Original 4 pole fast blo fuse holder
( 2x 1A and 2x 5A). 6mm x 30mm All Fast blo.
IMG_9646.jpeg


I decided to to replace all of them. The four pole
Holder is for the PCB. Sending over ~+7VAC and +12VAC.

Mine were +7.3VAC at Pin3/4 and +12V.6VAc at Pin 19/20. You can also measure at the anode of the each respective half bridge on pcb. Very accessible with mini grabbers.



The 3 pole fuse holder which was broken contains 2 x 2A fuses slo blow . One is for AC line snd the other is for monitor. The 1.5A slo blow is for lighting.

The Metal holders were brittle i actually broke another fuse clip by barely bending it.

New 3 and 4 pole fuse clip holders.

IMG_9816.jpeg
 
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Monitor chassis in this unit is a K4900. Rebuild cap kits are available if you choose to go that route.

Caps Spec

C201........................1000uF/16V
C205........................470uF/16V

C301.........................330/16V
C303........................2.2uF/63
C308.........................2.2uf/50V
C310..........................10uf/100V
C311....................4.7uF/160V
C313.....................100uf/160V
C315.........................1uF/100V
C351...........................1uF/100V
C352...........................47uF/25V
C354...........................47uF/25V
C373............................1uF/50V *(In parallel with D306)

C505.............................560uF/200V * (may have to be creative for this cap. Lead pitch on board
is ~ 23 mm.)
C506...............................22uF/160V
C507..............................47uF/160V

C701.................................1000uF/25V
C702..................................10uF/100V

Any Nichicon low impedance type cap will work. I put 105C rated. org caps are 85C rated. several places I up'ed the voltage. All of the caps are radial. I also increased filter cap C505. I had a 680uf/250V available.


Test point on Chassis for +130VDC rail.
T91 = + 129.5VDC


Post recap. Chassis no longer hanging over edge of mounting plate.:cool: The recap and reflow fixed the monitor issues.(y) She is alive!
IMG_9762.jpeg


Flyback anode connector. Notice clips snd tension plate. I've seen some with and some without the metal disc plate. Makes the connection to the tube a little more snug.
IMG_9686.jpeg


#3428 life. I want/Need to understand how to convert back to normal speed?

But before that. The control panels, coin mech and fan need a once over.
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The controller boards are next. The CO overlays are in good shape so I wont be replacing those. If you do you'll be going through this disassembly process.

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Three screws underneath and 4 quarter inch nuts inside along with a few sockets and control panel is out. This is post cleanup.
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This is the ms pacman business end with 4-way leaf switches. Rated E for everyone. .

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The contacts were in good shape. I cleaned them up with some denatured alcohol and a-little Deoxit. Goal was to disassemble and get to rubber/metal centering plate. If degraded, then replace. .
IMG_9747.jpeg

Post cleanup. Still in good shape. Replacements are available if needed.

Misc pics
IMG_9745.jpegIMG_9744.jpegIMG_9743.jpeg

After inspection and cleanup. Control panels Back together and repeat on other side.
IMG_9848.jpeg

Spent a little time replacing 3/4 in, t-molding. Puchased on amazon. The back plastic for control panels is from Delvie's Plastics. I cut them to 3.125 in. X 9.125 in. . They offer many acrylic translucent colors which are perfect for backlighting.
 
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With the board mod on this ms pacman i needed the mod/hack 6F Rom.

Picked up GQ4x4
IMG_0096.jpeg

Was able to get a ROM to write and verify.
HN462532G- Hitachi

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I was having issues with TI TMS2532A(21V) and TMS2532JL(25V)

It would WRITE but not VERIFY!

IMG_0095.jpeg

Chips erase fine and return all 1's. Blank check passes. Put a 9V supply to gq4X4. Im doing this on laptop. Maybe i need to move to desktop.
 
It had a G07 originally, and someone put in a 4900 Chassis since it uses the same yoke, Still has the G07 Monitor pan tho so is awkward
I've seen multiple varieties of stupid shit over the years but that one really blows. I want to say I had a G07 on a K4900 frame once years ago and even though the deflection boards mount the same way the depth of where the metal tabs line up to screw in are in different spots. lol

I would almost cut some wood to the size of the tray and screw it in through the bolt holes. you'll lose the ground off the frame but whatever, CRT ground has to be connected anyway right?
 
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