(Topic ID: 172650)

Meteor Sound ***Fixed***


By tomdotcom

2 years ago



Topic Stats

  • 35 posts
  • 9 Pinsiders participating
  • Latest reply 2 years ago by tomdotcom
  • Topic is favorited by 4 Pinsiders

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Linked Games

  • Meteor Stern Electronics, 1979

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20161108_114152 (resized).jpg

#1 2 years ago

Recently got myself a Meteor and had it setup downstairs. Game played great, but the settings and high scores were acting up so I bought a nvram board for u8/u13 on MPU.

I took the head off and took the game upstairs in 2 pieces. Now I am having sound issues. (see video below). The sounds are all muffled and cutting out.

The cables between the sound board and MPU are brand new. I also repinned and replaced the bottom 2 connectors to the sound board as well. I also swapped back in the old ram and that didn't make a difference. I did clip off the remote battery pack when I installed the nvram, but that shouldn't matter. I also triple checked all my connections.

Any thoughts what I should test or check next?

Thanks!!!

#2 2 years ago

When the sound cuts out, that sounds just like what I've had before on Meteor if you have ram that's too slow in it, I know you checked that so it's probably not the problem but maybe there's a socket issue on the ram? As far as the sounds being muffled, not sure about that one...

#3 2 years ago

Sockets are my next best guess as well....

#4 2 years ago

Did the sound problem begin when you installed NVRAM or when you moved the game?

Try something not invasive first... Sever the IRQ from the sound board. Easiest way to do this is to only use pins 1-32 on the J5 connector. If you have 34 pin plug, shift the connectors over two pins to the right on both ends of the sound board ribbon. That will leave 33 and 34 disconnected.

The IRQ is not required for the 6840 chip on the sound board and it being connected occasionally causes problems.

#5 2 years ago
Quoted from barakandl:

Did the sound problem begin when you installed NVRAM or when you moved the game?
Try something not invasive first... Sever the IRQ from the sound board. Easiest way to do this is to only use pins 1-32 on the J5 connector. If you have 34 pin plug, shift the connectors over two pins to the right on both ends of the sound board ribbon. That will leave 33 and 34 disconnected.
The IRQ is not required for the 6840 chip on the sound board and it being connected occasionally causes problems.

I installed the RAM and moved the game at the same time, before testing it. Dumb move

Ok I will look into that Thanks!

#6 2 years ago

I got a replacement Alltek MPU in it now. Still having same problem. I'm thinking it has to be a connector issue somewhere?

#7 2 years ago

Sound Board test points read:

TP 2(12v) = 14.2
TP 4(5v) = 4.78

#8 2 years ago

I took out the 6840 timer chip and reseated it. Wiggled connectors while triggering sounds. Still getting the same muffled and choppy sound.

#9 2 years ago

Make sure the Altek is set to Stern. Using the door buttons, clear all of the audits starting at switch 6. Garbage accumulates here causing weird things to happen. I think Altek also has a procedure to clear memory.

#10 2 years ago
Quoted from Superchicken:

Make sure the Altek is set to Stern. Using the door buttons, clear all of the audits starting at switch 6. Garbage accumulates here causing weird things to happen. I think Altek also has a procedure to clear memory.

I've done that with the new board and the old board too. But thanks for the tip anyhow Also the jumpers have been switched as well for Stern.

#11 2 years ago

Did you try messing with the volume potentiometer inside the cabinet? Sometimes these get dead spots or muted sound spots...

#12 2 years ago
Quoted from brenna98:

Did you try messing with the volume potentiometer inside the cabinet? Sometimes these get dead spots or muted sound spots...

Not a bad idea to rule out the potentiometer, I've got a Xenon that sounds are cutting out on and it's for sure the potentimeter. Slightly different case, solder joints causing problems and not a "dead spot".. but similar idea. As soon as I put a little pressure on it, intermittent sound issues clear up.

I also had a Gottlieb System 1 machine where one of the speaker wires had not been soldered to the lug and was just resting on it. That had me chasing board problems, ROM problems, etc for a while trying to figure out why sound worked.. and then suddenly didn't.

Something else is to enter SOLENOID TEST via the self-test button, solenoids 20-29 during that test should be sounds. Could be a way to check if just certain sounds are affected.

#13 2 years ago

I did mess with the volume pot, didn't help.

I did run the sound test and some of the sounds are messed up in it I think. I'll post a video of what my sound test sounds like.

I did also check the speaker connections and they're good.

#14 2 years ago

Ran the solenoid/sound test a few times.

See here:

#15 2 years ago

20/21 don't sound right compared to a couple vids on youtube..

ie:

and

#16 2 years ago

did you try disconnecting the IRQ from the 6840 on the sound board? Either move the j5 connector so the last two pins are not connected or bend the IRQ pin out of the 6840 socket. No games need it to be connected. I have seen the IRQ signal at the 6840 cause problems more than a few times.

If its not a connector problem, fixing the sb300 is a bit more advanced. You have to watch the signals travel through the board during solenoid test or while triggering sounds in game mode

#17 2 years ago
Quoted from barakandl:

did you try disconnecting the IRQ from the 6840 on the sound board? Either move the j5 connector so the last two pins are not connected or bend the IRQ pin out of the 6840 socket. No games need it to be connected. I have seen the IRQ signal at the 6840 cause problems more than a few times.
If its not a connector problem, fixing the sb300 is a bit more advanced. You have to watch the signals travel through the board during solenoid test or while triggering sounds in game mode

One of the sound board to mpu connectors is keyed though and missing that wire in the connector.

#18 2 years ago

The replacement cables are keyed at pin #29. Original cables could have been Molex parts with key pins, or ribbon cables that weren't keyed.

If you pop out the 6840 and bend pin #9 (IRQ) slightly outward so that when re-inserted it misses the socket, that will allow you to disconnect IRQ and you can then just remove the 6840 again and bend it back straight after testing that theory. Just bend it very slightly -- you don't want to put a kink in it or it'll snap off... just needs to "miss" the socket when you re-insert the chip.

If you need help finding pin #9.. with the chip oriented so the notch on the top of the IC is on the left.. pin #1 is the left-most pin. Count over to pin #9 starting at that pin.

#19 2 years ago

I could try bending that 6840 irq pin out....but dont want to wreck it.

#20 2 years ago
Quoted from acebathound:

The replacement cables are keyed at pin #29. Original cables could have been Molex parts with key pins, or ribbon cables that weren't keyed.
If you pop out the 6840 and bend pin #9 (IRQ) slightly outward so that when re-inserted it misses the socket, that will allow you to disconnect IRQ and you can then just remove the 6840 again and bend it back straight after testing that theory. Just bend it very slightly -- you don't want to put a kink in it or it'll snap off... just needs to "miss" the socket when you re-insert the chip.
If you need help finding pin #9.. with the chip oriented so the notch on the top of the IC is on the left.. pin #1 is the left-most pin. Count over to pin #9 starting at that pin.

Ok gonna try this right now...

#21 2 years ago
Quoted from tomdotcom:

I could try bending that 6840 irq pin out....but dont want to wreck it.

Apparently if you wreck than IRQ pin, it doesn't matter since it's being said IRQ is not used at all

Other option is if you have the old set of cables, try those.

If you only have the new cable, your only other option would be to use a very tiny flat-blade screwdriver (from an eye glass set for instance). You can release the Molex pin on one side of the cable by pressing in the locking tab on the pin (there's this slot/window on the back-side of the Molex connector where you should be able to see the locking tab). You'd need to push that in so it no longer catches inside the connector (locking the pin in the connector). Only thing is, they're kind of a PITA to bend back if you're not used to doing it.. since you have to push the tab back the opposite way so it can lock again.

I'd just lightly bend pin #9 out on the 6840. You'll be okay that way and it should be pretty quick.

#22 2 years ago

Ok I bent 9th pin out on 6840. Hooked it all back up and getting same result. Thanks for all the help so far guys. Bit of a head scratcher

#23 2 years ago

Does anyone have a part number or know the values of the volume pot?

#24 2 years ago

Sound worked fine just 15minutes before I moved it upstairs and removed all the connectors to take the head off.

That has to be the biggest and most likely clue? That clue would lead me to think I have a bad connection somewhere.

I tested continuity from the mpu to the soundboard, and got beeps all the way along that 34pin connector. So the data should be getting to and from those boards.

What other connectors should I focus on?

#25 2 years ago

Maybe another clue? This is what the game is displaying for a high score.

20161108_114152 (resized).jpg

#26 2 years ago

I reset that high score and all adjustments and it reverted right back to that weird high score thats missing a digit...

#27 2 years ago
Quoted from tomdotcom:

I reset that high score and all adjustments and it reverted right back to that weird high score thats missing a digit...

Is that with the Alltek in the game or back to the original board?

Also is there a setting on the Alltek for "MPU-200" ?

#28 2 years ago

On the Altek instruction sheet, there are instructions on how to clear the board, sometimes they get confused. From memory you move all the dip switches down or something. That has fixed a couple of issues I have had with Alteks (including one on Meteor)

rd

#29 2 years ago

You could have a bad transistor on that display. Try swapping displays and see if it moves. If it does, it's on the display, if not, something on the MPU or wiring.

#30 2 years ago

All the displays work fine. It just leaves a digit off for high score, so its getting bad data or something.

I did see that thing about clearing the board rotordave. Ill try it, but the old mpu and new mpu are doing the same thing. So id guess that aint gonna help But will try it anyhow..

#31 2 years ago
Quoted from acebathound:

Is that with the Alltek in the game or back to the original board?
Also is there a setting on the Alltek for "MPU-200" ?

With the alltek and I did move the jumpers on it to the right spot

#32 2 years ago

Yeah, clear the audit data as was suggested. If that doesn't do anything, just for the heck of it try leaving the J1 harness disconnected from the MPU & play a game "blind" (ie. no displays, no feature lamps). Start a game and trigger switches for sounds & see if it sounds the same. You may also want to try going into Solenoid Test again.. only with the playfield switch harness (J2 on the MPU) disconnected.

#33 2 years ago

Omg I think that fixed it!!!!!!!

I changed the dipswitches on Alltek board to clear memory. Then put it back to Meteor, and it has proper sound....so far....play testing now....

I am forever grateful for all your help. If that was the problem all along. I wanna smack my head on the wall. But at least I learned alot about this era of game. Now I need a Stargazer and Quicksilver for beside it

#34 2 years ago

I did try and reset the original board too before all this. Must it must not have worked when I did it.

Is there any better feeling than getting a game working right!!! This game also had major problems with resetting the Meteor bank, but I fixed that by adjusting the lift rod on one end. Took a few tries.

Now I can treat the game to new rubber, rebuilt flips and a good scrub

#35 2 years ago

Play tested it a bunch. Sound and settings are working perfectly. First time I've had the game 100%

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