Crap, i forgot to measure it for you.

Gimme a half-hour, I'll go donw and measure mine.

Okay, I measured max 35k ohm, min 2ohm. (Surprising, since I would have put money down it was 10k as well..)

Mine looks original, but oddly with one lead disconnected, every combination of leads from the pot varied depending on turning the pot. None of the three were a fixed resistance.

Yeah - the only thing I can think of is that I was getting some leak-through current through the audio board. I may re-try the reading tonight, and disconnect all wires to check.

How long does a charge last? The only reason I've been staying away is I don't want to lose settings if I'm out of the house for a week or two on vacation and can't turn the games on.

Cool, thanks guys, I like those odds. Will give it a try on the MrMrs Pac Man I gotta restore..

Okay, stupid question guys..

I need a 28-pin housing for the MPU connector, J1. I checked Digikey and Mouser, both don't carry .100" headers in 28pin. I can get a 30-pin, but I'd rather get one that matches, first.

Thanks!
-Mike

Yeah. 25-pins are also running dry.

Odd question, would be interested in hearing other's thoughts.

I was talking to my boss today about those 28-pin headers, and since he's been desiging PCBs for a lot longer than I have, I asked him how he would handle connections like that, if he was to redesign the MPU boards. (Something like Alltek and their boards..)

I am against re-desining the larger headers - i.e. leave them as-is, and like mentioned above, use two smaller connector housings and fit them together. (Two 14-pins. Or a 14-pin and two 7's, etc.)

He was strongly for redesining the headers. (i.e. J4, where you have sol data going out and power coming in, he was for making it 'logical' - make an 8-pin header for sol data going out, and then the rest of the pins for power coming into the board.) His argument was this - you're making a new product, use whatever connectors you can that will help make it last. If that means the end-user has to do a little more work (repinning a header), that's an acceptable set-back, if it means that in twenty years, the users can still get 7-pin housings and not have to worry about piece-mealing multiple headers together.

So, I was just curious on thoughts - if someone like Alltek or Rottendog came out with a new MPU board, but it had some small changes to the connectors, would that turn you off?

Interesting, thanks for the discussion guys - Yeah, I agree that if it's NOT backwards compatible (directly) there should be a way to make it - i.e. add a second header to the board, or a small adapter cable to be able to plug the original harness into the new headers.

I'll bump this as I'm curious as well.

Also add on, were the handles black, or steel? (Mine is steel/metal, and I haven't found a replacement online..)

Do you get 100v AC on the top of the filter? (First pic..) If yes, do you get voltage on the BOTTOM of the filter?

I have a question that y'all will make fun of me for, I know it:

I have a Mr. & Mrs. Pac-Man (Bally) that I'm shopping it for someone, and I see that there's a bulb under the apron with a frosted white "insert plug" in the apron. ..What's that for?

Quick question with those familiar with the 6 & 7-digit displays -

How often, in average, do components fail on the board? (i.e. Not the glass itself, but the decoder, transistors, etc.)

Ah cool, thanks!!

Hey guy -
Any EE folks in this thread? Or folks that are *really* intimately familiar with teh MPU-200 flavor of the boards? If so, could you drop me an email? I have a couple really specifically odd questions.

I just ordered two of those Amazong speakers. (One of my Meteor, and one for Mr/Mrs Pac Man I'm restoring for a friend.) I don't need bass-thumping sound (hell, on Meteor, on a good ball... that would cause you to go deaf!) so these should work well.

Really technical and specific question -
Does anyone know the address of SW33 (The 'reset' switch)?

Tryin' to modify my ROM revision to have that button enter a credit when not in test mode, and just trying to find the call.

-Mike

Marco -
That's perfect, thanks! I have the credit address already, so just need to increment one to that register - *IF* we're not in test mode. (Checksum is already disabled; dangerous, but, easier for testing..!)

Hah! interesting..
You may have a bad PIA chip. If the game sees all the dip switches OFF/closed, it will go into test mode. I can see that meaning that if a PIA is bad, a playfield switch may be read as a duip switch, causing the PIA to send the wrong signal back to the CPU, thinking all were then off.

I got my speaker, and plugged it in. My OEM speaker was fine - had no issues. so keep that in mind with my comments below..

This linked speaker works fine, sounds almost exactly the same to me; the upper tones seem slightly muffled, less clear than the OEM speaker.

So, if your OEM speaker is fine, then this won't be an upgrade. If your original speaker is damaged, this is a pretty good OEM replacement.

Hey guys -
Posting here as it's low priority, but I'm looking for price plates for a classic Bally coin door. Either one is fine -
$1 / 5 plays
$.50 / 3 plays (2 plays is acceptable too..)

The only catch is.. has to be a color OTHER than *green*. White, Yellow, Red, Orange, Blue, Purple, all fine. Just not green.

The $1 I can use the existing quarter metal plate, but if there's a $.50, I'll need the metal plate with a larger cutout. Of course, willing to pay..!

Edit: Found, thanks!

Should be in the freely available schematics?

I thought you adjust them by adjusting the lifting bar - so that when IT falls, it's not resting all the way down, holding the targets level with the PF?

I don't know of a pinball that DOES NOT save credits when it's turned off.

And I completely mis-read your post.
Okay, so, normally, yeah, the game will store credits. Without a battery, though, yeah.. in theory it should forget without power, and without NVRAM.

No reason NOT to use an original board. There's not much there to really go wrong - and if some fixes are done (i.e. Reset circuit, etc) when necessary, there's no reason they won't last forever.

Hey guys -
Anyone know *how many* games use the Aux Lamp driver?

Oh, well... Huh. I don't know. I guess I should look at the differences, first now, to see which one I'm looking at. (I'm *looking* at schematics for the one that's in Mr. & Mrs. Pacman.) If the two are electrically compatible, then it doesn't really matter. if they're NOT, I need to see why not.

Okay, did some research, and yeah, didn't realize there were two different models. I am meaning the larger one, -52.

Silly question..
On the -23 Lamp Board, can someone explain to me what R70 is used for? It *appears* to only feed the test point?

Ah! Very cool. Thanks!

Usually corrosion, and depending on the socket, bad tension in the pin holes.

Did you check your Zero Crossing?
Since you ruled out the MPU and LDB, the zero crossing is coming from the transformer and line input. If your line input is wonky (UPS? Conditioner? Lightning Arrestor?) and not giving a good sine wave at 60Hz, or some bad, leaking diodes on the transformer board, that can cause the zero-cross to be wonky - on both MPUs..

FTR, this is not how you test the zero crossing. The zero crossing is high/low, pulsing. You would need a multimeter that can report frequency. Better yet, an oscilloscope to see the high/low pattern.

However, since everyone else is sending you off on strobe hunts, I'll be quiet.

The only thing I can think of is some capacitance on the data line or strobe line, so that the strobe lines are too far advanced (or the data lines are too far behind) the strobe, causing the decoder chips to erroneously think they were being addressed, up until the datalines catch up.

FTR, earlier revisions of this board had 8 pins. Later revisions had 9. The 9th pin was another GI Lamp out (I believe, maybe Feature Lamp)? Depending on your game, your game may not use all 9 pins. (i.e. Meteor has only 8.)

Save money, get a Weebly MPU. Can also then run test ROM software.

Pin 1 on sound board goes to Pin 1 on MPU.
The pins that are skipped are at the high end. (33, 34 I believe, going off of memory.)

Keep in mind that you would technically need TWO resistors -
One to provide the load across the feed to the driver (i.e. between the two pins), and then one in series with the LED for limiting current/voltage to the LED, to avoid blowing it up. It looks like that IS the case with the second picture there.

That corner. Holy hell..!

Interesting. Willing to do some testing. Some bodies are different sizes, and will they have a cap/res pair for anti-flicker?

Are you absolutely sure_ the hum is coming from the transformer, and not the speaker(s)?

Okay, I was just making sure - if the transformer WAS the one actually humming, a cap job on the sound board wouldn't fix it.

Yeah, caps would fix this. Also possible a diode or resistor is out of spec, though it's been a loong time since I've looked at that board, so I couldn't help on which ones.

Huh.
Is your game's plug properly grounded? If the outlet grounded? Sounds like the whole game may be floating. :/

Have you replaced the coils?

Some places back in the day had 105 or 110 volts fed to it instead of 120. One of my old houses was like this back in NW Illinois. We'd get 107-110v. I can imagine that that little difference could affect coil power and such?

I know WPC machines had a 100v (maybe 105v?) plug for Japan, too.

It says right there in the manual - Page #6, under "Balls Per Game"- for 5 balls, switch #32 needs to be off, and #31 needs to be on. For 3 balls, both need to be off. The switch numbers are on the Alltek board, to the RIGHT of the dips. #31 and #32 are at the top, as you've discovered.

The next two pages are 'recommended' settings for a 3 or 5 ball game. To avoid operators from setting the game 'too easy' or 'too hard' for on-location.

No worries! Alltek make the switch #'s so small as well, they're really easy to miss.