Pole Position : no acceleration .. Gas pedal not responding

1- i do not know if that 4066 from ms pac is working. The ms pac board is a salvage board i use for parts...the parts ive used off it in the past worked on other games so i can only assume the 4066 is good...but again..i never seen the ms pac board working.

Well, if you have the same exact results, chances are the part is probably OK. Could still be bad, but for now let's just assume it's OK until you do some more test.


2 - i tried a different method, for the first time, for removing the soldered chips...on the solder side i used a heat gun to heat up,the chip area..held the heat gun about an inch or two from the board...while on parts side i clamped down on the chip ends with a chip removing tool...i then slightly tugged on the chip as it heated below until it slipped right out...i did the same on the pp board to remove 8k. Once removed i used a desoldering gun with a .08 tip and cleaned the holes..slipped the socketed chip in then soldered it in....i loaded it into the cabinet and the game booted right up...but still no gas. My concern was the heat from the heat gun would possibly damage components close to 8k area because it does get really hot in the whole area...but the game lit right up so i will assume there was no heat damage to close components....and there was zero discoloration on solder side from the heat...zero burned looking area....so that was a success i feel as far as procedure goes and will do it in the future from now on.

Heat Gun = Bad idea. If you plan on doing a lot of board work get a good desoldering gun. The Hakko FR300 is good, but there are cheaper alternatives if the price is a problem.

3 - I did not logic probe anything on 8j or 8k. I was too discouraged to go further so i shut it all down until i get new ideas/suggestions what to do next...maybe replace 8J next?

This is the next logical step. Break out the logic probe and start at pin 6 of 8J and work your way backwards. See further below....


4 - i picked up a 5k volume pot from radio shack thinking that may work in place of existing pot...after i replaced 8k i had zero gas with the new pot....so i figured maybe that new pot wouldnt work because its for volume? ??..i dunno..seems like it would work, right? Anyway, i then removed the new pot and reinstalled the original pot thinking with the "new" 8k the original pot may be needed in the game...zero luck..no gas.

I don't think your existing POT is the problem. Even with a bad spot in it, you should get something. Might not be the full throttle, but at least partial or intermittent.

So maybe now i will order a new 4066 for 8k and may as well buy a new chip for 8j.

Hold off on this until you've checked the rest of the circuit with your logic probe. You might be chasing something that isn't the problem.
4066+diagram.png


Pin 6 of 8J is connected to Pin 11 of 8K. So you want to use the logic probe on Pin 10 of 8K which is the INPUT side of things and Pin 11 is the OUTPUT side of things (The diagram above has them reversed, but that's ok).

Pin 12 of 8K is the control between pins 10 and 11. If Pin 12 never changes then 10 and 11 will never be connected (or always connected). So if Pin 12 is pulsing and pin 10 never changes, then you follow Pin 10 back to C12, CR9, R101, R107, R108, etc... you want to make sure the resistors are within spec, the cap is good, etc...

If Pin 12 is NOT pulsing, then you follow pin 12 back to pin 8 of 8K. Pin 8 and 9 are the OUTPUT and INPUT and pin 6 controls those two.

If pin 6 isn't working then you follow it to Pin 7 of 8E (page 12 of the schematics) which is an LS259. If that's not pulsing then 8E could be bad.

Pole+Position+Gass+Pedal.png


Hopefully that should be enough to get you going. Gamefixer can correct me if I'm wrong since he knows more about this than I do :D
 
Well, if you have the same exact results, chances are the part is probably OK. Could still be bad, but for now let's just assume it's OK until you do some more test.




Heat Gun = Bad idea. If you plan on doing a lot of board work get a good desoldering gun. The Hakko FR300 is good, but there are cheaper alternatives if the price is a problem.



This is the next logical step. Break out the logic probe and start at pin 6 of 8J and work your way backwards. See further below....




I don't think your existing POT is the problem. Even with a bad spot in it, you should get something. Might not be the full throttle, but at least partial or intermittent.



Hold off on this until you've checked the rest of the circuit with your logic probe. You might be chasing something that isn't the problem.
4066+diagram.png


Pin 6 of 8J is connected to Pin 11 of 8K. So you want to use the logic probe on Pin 10 of 8K which is the INPUT side of things and Pin 11 is the OUTPUT side of things (The diagram above has them reversed, but that's ok).

Pin 12 of 8K is the control between pins 10 and 11. If Pin 12 never changes then 10 and 11 will never be connected (or always connected). So if Pin 12 is pulsing and pin 10 never changes, then you follow Pin 10 back to C12, CR9, R101, R107, R108, etc... you want to make sure the resistors are within spec, the cap is good, etc...

If Pin 12 is NOT pulsing, then you follow pin 12 back to pin 8 of 8K. Pin 8 and 9 are the OUTPUT and INPUT and pin 6 controls those two.

If pin 6 isn't working then you follow it to Pin 7 of 8E (page 12 of the schematics) which is an LS259. If that's not pulsing then 8E could be bad.

Pole+Position+Gass+Pedal.png


Hopefully that should be enough to get you going. Gamefixer can correct me if I'm wrong since he knows more about this than I do :D

That is pretty advanced....but i need to tackle this...the only way i can learn. Thank you for laying it out for me.
 
+1 on the heat gun comment. Only do that on a board you don't care about.

The rest of the post looks spot on to me. :)
 
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Well i messed with it a little tonight but didn't do any of your suggestions just yet because i didnt have a lot of time....

Anyway...i wanted to do a continuity test from the tabs of the pot to the edge connector and to the 8k and 8j.

So i put the black lead on the tab ofvthe pot where black lead is soldered....touched edge connector for that black wire and got a beep....then i touched leg one of 8k and got a beep....so from pot tab to chip 8k i got a beep and beeps on a few other legs on 8k and 8j.

I then put the lead on tab with red wire soldered to it....then touched edge connector where red lead goes and got a beep...and i go to touch legs of both chips and got no beeps.....so i touched the back side of edge connector to front of connector where it slips onto the board and got a beep...so the connection is there between connector and where it slips on.

Should i get a beep on the red wire to either 8k or 8j? If so, then that may be the issue since im not getting any continuity.
 
So i put the black lead on the tab ofvthe pot where black lead is soldered....touched edge connector for that black wire and got a beep....then i touched leg one of 8k and got a beep....so from pot tab to chip 8k i got a beep and beeps on a few other legs on 8k and 8j.

If you mean Pin 1 of 8K then that is Ground and you should get a beep. As for the other legs, it would be important to know which ones.

Also is it a continuous beep or just a quick beep? If it's a continuous beep then that means it's a dead short (no or very very little resistance) between the points. For ground that's good if there are no components between point A and point B.

But say you are testing from the edge connector pin F to pin 3 of 8K, you should NOT get a continuous beep, just a quick one (depending on your meter). If you get a continuous beep that means that R108 is probably bad. Your meter should show around 1K of resistance (might be a little higher or a little lower, but close).


I then put the lead on tab with red wire soldered to it....then touched edge connector where red lead goes and got a beep...and i go to touch legs of both chips and got no beeps.....so i touched the back side of edge connector to front of connector where it slips onto the board and got a beep...so the connection is there between connector and where it slips on.

Should i get a beep on the red wire to either 8k or 8j? If so, then that may be the issue since im not getting any continuity.

Without knowing the locations you are testing it's hard to say.

Testing from the pot to the edge connector is good for testing the harness to make sure it's good, but depending on where you test on the PCB, will determine whether or not you should get beeps.
 
If you mean Pin 1 of 8K then that is Ground and you should get a beep. As for the other legs, it would be important to know which ones.

Also is it a continuous beep or just a quick beep? If it's a continuous beep then that means it's a dead short (no or very very little resistance) between the points. For ground that's good if there are no components between point A and point B.

But say you are testing from the edge connector pin F to pin 3 of 8K, you should NOT get a continuous beep, just a quick one (depending on your meter). If you get a continuous beep that means that R108 is probably bad. Your meter should show around 1K of resistance (might be a little higher or a little lower, but close).




Without knowing the locations you are testing it's hard to say.

Testing from the pot to the edge connector is good for testing the harness to make sure it's good, but depending on where you test on the PCB, will determine whether or not you should get beeps.

I get continuios beeps on legs 1 and 2 of 8k....and a few others...i will re check today....on 8j i get real quick beeps

All of this is with black wire from pot....red wire i get nothing.

Tonight after work i will list each leg and what i get for continutiy.
 
Youtube vids..first is testing 8j and 8k with logic probe..second vid is of 8e testing

Game was in attact mode during testing.

Also, if it means anything, i tested the following below with the logic probe:

R99 - tested both legs...both stayed solid hi with no pulse
R102 - tested both legs...both stayed solid low with no pulse
R107 - oops..forgot to test this one
R108 - tested both legs ...both stayed solid low with no pulse
CR10 - tested both legs...both stayed solid low with no pulse
CR7 - tested both legs, + side stayed solid high, no pulse...other side stayed solid low, no pulse
CR8 - tested both legs, + side stayed solid high, no pulse...other side stayed solid low, no pulse
CR9 - tested both legs,...both stayed solid low with no pulse
C14 - tested both legs...both stayed solid low with no pulse
C12 - tested both legs...both stayed solid low with no pulse
C10 - tested both legs, + side stayed solid high, no pulse...other side stayed solid low, no pulse
C11 - tested both legs, + side stayed solid high, no pulse...other side stayed solid low, no pulse
C15 - tested both legs, + side stayed solid high, no pulse...other side stayed solid low, no pulse
C13 - tested both legs...both stayed solid low with no pulse.

First vid testing 8j and 8k

https://youtu.be/x60D_NnYdiI

Second vid testing 8e

https://youtu.be/4QJg5-G_fD4
 
I wonder if "GASEL" is actually Gas Enable? Seems kinda silly to have that but it was low in your first posted video. start a game and see if it goes hi.

Pin 5 and 6 on 8K.
 
I wonder if "GASEL" is actually Gas Enable? Seems kinda silly to have that but it was low in your first posted video. start a game and see if it goes hi.

Pin 5 and 6 on 8K.

Ive shut it down for the night..i will do it tomorrow after work.
 
I wonder if "GASEL" is actually Gas Enable? Seems kinda silly to have that but it was low in your first posted video. start a game and see if it goes hi.

Pin 5 and 6 on 8K.

Agreed. I think if that's low, 8K won't do anything.

Could he manually pull the pin high to test that way?
 
Agreed. I think if that's low, 8K won't do anything.

Could he manually pull the pin high to test that way?

Sure.

I like to start with something like a 470 ohm resistor when I'm trying to force a pin one way or the other. If that doesnt work you can move all the way down to a 47 or so ohm resistor. What you dont want to do (unless youre sure of whats going on with that pin) is tie is directly to GND or +5. Reasoning is that lets say the chip that drives GASEL is internally shorted to GND. If you tie that pin to +5 you are probably going to burn the trace open and might even pop the IC. If the IC is bad thats no big deal but burning the trace open would suck.
 
Pole boards

The gas pedal on my pp no longer works. It was working perfect and i get nothing...so rev up sound..nothing...car wont move.

In self test no number increase when i press gas...everything else works.

I am getting 5 volts to it.

Manual states its either a bad A-D converter on the CPU PCB or a mechanical problem...as of now i see no mechanical problem.

And what/where/location is the A-D converter?

I have brand new A to D convertors + 4066 chips + sockets if you need them.
 
FYI...

I just tested GASEL on my board on the bench. During power up it was low, at the explosion sound it started to pulse (switch between hi/low). In test mode it pulses and my gas pot works. If I hold pin 6 low I get no gas pedal response in test mode.

I'd look at that GASEL signal and see what its doing.
 
FYI...

I just tested GASEL on my board on the bench. During power up it was low, at the explosion sound it started to pulse (switch between hi/low). In test mode it pulses and my gas pot works. If I hold pin 6 low I get no gas pedal response in test mode.

I'd look at that GASEL signal and see what its doing.

Is gasel pin 6 and 5 on 4066?

If so, i should hold probe on pin 6 or 5 then start the game and see what the probe does?
 
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Is gasel pin 6 and 5 on 4066?

If so, i ahould hols probe on pin 6 or 5 then start the game and see what the probe does?

Yup, 5 and 6. Start a game, put it in test mode, either one should change it to pulsing from the looks of things.
 
Yup, 5 and 6. Start a game, put it in test mode, either one should change it to pulsing from the looks of things.

Pin 5 and 6 both stay solid low when i turn the game on and stays that way. I set logic probe on a leg..turn game on and instantly is low...not even a glimmer of a change.

I also switched the game to test mode with the logic probe on the pin and nothing changed. I also started a game, and same results.

I did this for 5 and 6 individually.

Then for shits and giggles i put logic probe on back side of edge connector to black wire...it beeps low...i press the pedal...it stays low...i then put logic probe on tab with black wire on pot...stays low.

Then i put logic probe on back side of edge connector to red wire and it stays high....i press pedal, and stays high, i put logic probe on pot tab which red wire soldered to and stays high when i press pedal.

Shouldnt probe change from high to low or visa versa at edge connector or pot when i press pedal?

(I did do these edge connector and pot tests with the game coined up to qualify)

So i have a high (red wire) and a low (black wire) signal going to F of edge connector.
 
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