Ms Pac Man Monitor Problems

wxforecaster

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I'm not sure if the monitor problems below are a cause or effect, so I posted here first.
(#crossposted to r.g.v.a.c. usenet)

I finally got my hands on a Ms. Pac cocktail over the weekend (ALWAYS
wanted one). The owner said that it was booting into the memory OK
screen and not doing anything else. THAT was the easy fix (he had the
interlock switch on).

However, now that it boots, I've noticed two (possibly unrelated
monitor issues).

1.) http://www.interwarn.com/pictures/IMAG0056.jpg
As you can see the picture is squashed horizontally, taking up maybe
1/3rd of the screen. There is some overlap. Also, the graphics seems a
bit 'wavy'.


2.) The color is good, but if I so much as tap on or move the game, it
flickers between good colors and what I would term "washed out"
colors.


I'm mainly a pinball guy, so I do have experience soldering, etc...


Any ideas on what's going on and what the most cost effective way
would be to get her up and running? The rest of the game is in AMAZING
condition for a near 30 year old vintage item. Not sure if the CP
overlays/glass underlay was redone or not, but it looks great!


TIA,
Evan
 
Cap kit should fix you up. As time goes on the caps are drying out and failing. Soon u will just get a line or nothing at all on the screen. Replacing all the caps should get you back to a full screen.
 
Thanks for the quick followup! Over the years I've probably seen hundreds (if not thousands) of posts on this subject related to aging vids.

The repair seems VERY inexpensive and hopefully something I can do w/o electrocution :)

Evan
 
Paul,

The inside is too filthy to get some sort of marking off the monitor. Can you confirm for me what Well Gardner model monitor is in a Ms. Pac cocktail? Want to make sure I get the right cap kit.

Do these kits typically come with instructions to safely remove the board for access?

Evan
 
Do you have soldering experience? This should be a repair that you can handle on your own.

Bob Roberts has your cap kit. Get the G07 repair kit. Get the Super kit if your Horizontal Width coil is broken, and get the Deluxe kit if you want to bulletproof the monitor.

I'd highly recommend replacing the flyback while you're doing the repair.

Use the 'new' quick ordering tool that one of our KLOV'ers so loving programmed:

www.orderfrombob.com

:)
 
Paul,

The inside is too filthy to get some sort of marking off the monitor. Can you confirm for me what Well Gardner model monitor is in a Ms. Pac cocktail? Want to make sure I get the right cap kit.

Do these kits typically come with instructions to safely remove the board for access?

Evan

this is a electrohome go7 . very common monitor, very easy to work on.
 
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On this forum, I'm sure this goes without saying, but Bob Roberts is one helluva guy. He cross shipped my cap kit (apparently on the Concorde), as it arrived today!

Hopefully I'll report back with good news. At least now I feel like I have the safe knowledge of being able to discharge the monitor without seriously "MAME"-ing myself :)

Evan
 
OK,

I discharged the monitor and removed the boards from the chassis without a hitch.

These (among everything else in the cocktail) is disgusting and will likely require several cans of compressed air + vaccuum to remove all the dust, dirt and mouse feces.

My question is, the boards are pretty disgusting. Is there a recommended method of q-tips + something to clean them? I don't want to do any damage while doing the re-cap, but I hate to put something this gross back into the game if I could take some precautionary cleaning measures.

Evan
 
i use alchol and q tips, but i have read people using simple green and a garden hose but i personally never did that.
 
Rinse it off with the hose to get most of the crud off, then chuck it in the dishwasher, but don't bother with the dishwasher's heated dry function. When it's done, shake off what water you can, put it in the oven at 150 or 175, however low it goes, and let it sit for a half hour to an hour. After that it should be nice and dry. Now it'll be much easier to recap and work on.

I'd suggest replacing the flyback on a G07, it's a really common failure in these.

-Ian
 
The alcohol + qtips seemed to get the job done with the cleaning. The wife balked at the dishwasher idea :)

OK, a couple issues on the recap. It appears the previous owner had some hackjob come in and attempt this project half a$$ed as SOME of the caps have been replaced, and poor re-soldering all around.

With a steady hand I got most of the work + the 303 mod done.
I have two lingering issues:

1.) Plate through holes on both sides of 511 are gone. How to fix and ensure continuity to adjacent components? I'm a vid noob and used to two sided pinball boards and being able to "stitch" it. I guess the only solution would be to scrape away the "green" on the board to expose the copper, but I'm curious what is the correct way to do this scrape job.

2.) Cap 701/506 are under some sort of protective metal shield that I cannot for the life of me figure out how to get loose.

My flaky "red" is hopefully related to E1 on the E1-E6 connector which I found has a less than stable solder joint.

Evan
 
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that shield is held on by two solder points, desolder them and it falls right off. not sure of your other problem usually i just solder a jumper to the next point, take a pic so we can see whats going on.
 
As for 511 holes, here's the damage I'm trying to figure out how to repair.

http://www.interwarn.com/pictures/IMAG0073.jpg

Scrape away the green solder mask with an Xacto knife or similar, to expose the copper trace. Fold the capacitor leg over and solder it to the trace. For the lower one, since the ripped out pad is in the middle of a longer trace, you'll need to be sure to make good a good connection on both sides of the trace. You can use bits of cut off component legs or wire to make jumpers if you need to.

-Ian
 
Thanks Ian. Apologies for the out of focus picture. The good news is that I still have good continuity on the lower 511 trace between T501 and C521.

Will be out of town for a week so it'll be a while before I can hopefully finish this job off right, so hopefully the suspense doesn't kill anyone. For a first timer, admittedly this has not been too intimidating thanks to the awesome documentation provided and clarification by Paul/Ian/Rob others.

In fact, since I'm not going to be here for a week, I may just go ahead and order the flyback too and ensure everything is fresh.

Evan
 
Alright, back in town and looking to finish the job off and rebuild those burned/missing through hole plates

The one thing I am uncertain about is C301 and C520. Neither of these were shown on the "cheat sheet" graphic that Bob included with the kit. I found them and replaced them, but what's interesting is that the capacitors for both are non-polarity. Is this correct? I noticed a + marking on the underside of the board for C301, but not for C520.

Evan
 
Both of those caps are bipolar, 3.3uf capacitors, and must be replaced with the same. They're not included in the cap kits generally because they're not common failures. Don't replace them with a polarized electrolytic.

-Ian
 
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