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Super Monaco GP Airdrive

OK, I found pin 5 on IC163 toggles between high & low with the start button (high when start button is pressed). Results at the driver board are as follows : -

opto pin out.png


table-chart PC3.png


table-chart PC4.png
 
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Hi,
I first had to understand what you listed in the tables. :D
But now it's clear to me, you measured the connector pins 1-8 of the ICs, that wouldn't have been necessary.
Measuring the 8 signal lines would have been enough.

Actually everything seems to be ok so far, only the signal marked in red should be LOW.
Maybe a measurement error?

PC4.JPG


You can measure the inputs and outputs of PC3 and PC4 to see whether they switch identically.

If everything fits, I would burn a new EPROM or compare it with the driveboard file.
I don't know if you have the opportunity to do this?
 
I'll double check that one result. So PC3 & PC4 should give the same results? I don't have equipment to burn ROMs. Can a cheap burner be purchased? Are you able to share the file or a source for it? I'll see if there is a ROM burning service on the UK. I've read on USA forums there are companies that offer this service.

Thanks again!
 
Thanks. I know NOTHING about this kind of thing (like most things!!). Do you know what kind of EPROM I would need?
 
best we start again from the beginning.
IC164 is responsible for signals 1-7, IC163 is responsible for signal 8.
It's a bit different on the driveboard, where PC4 is responsible for signals 1-4 and PC3 for signals 5-8.

Now please only measure the 8 signals, follow the path from the mainboard to the driveboard and enter the results again in a table. An example of the course of signal 1: Signal 1 goes to pin 1 (input) of IC164 on the gameboard and comes out again inverted from pin 16 (output). Then the signal 1 goes to the connector, via the wires to the driveboard connector, then the signal 1 goes on to pin 8 (input) of PC4 and comes out again on pin 9 (output).
For the signals 2-8 you will surely find out the signal course yourself.

First make a table with signal 1-8 at the input of IC164 and IC163,
then a table of signal 1-8 at the output of IC164 and IC163.

On the driveboard make a table of signal 1-8 at the input of PC4 and PC3,
then a table of signal 1-8 at the output of PC4 and PC3.

I hope you can understand my bad english, it's not so easy for me to explain complex troubleshooting in another language.
 
@RedFighter I've done IC163 & 164, typing table up now. On the driver board I'm not 100% sure which pins I should be testing?

Screenshot 2022-12-20 at 18-37-45 Super Monaco GP - DELUXE - Air Drive - Arcadezentrum_Retroga...png


eg, on A1 should I measure pin 7 or 8 on the input & 9 or 10 on the output? Sorry for stupid question!
 
Hi sega_man,
now the table looks good and i can understand it better.
To explain it a little better, the 8 signals from the Sony chip run to the inputs of the 2 ICs and the same 8 signals come out at the outputs, only they are then inverted.
So non LOW becomes HIGH and vice versa.

I compared your 2 tables and it looks very good. The signals coming from the Sony chip are fine, that's worth its weight in gold.
However, the signal 1, 2 and 3 have the wrong levels in test no. 6 at the output of IC164.
You see these 3 signals are not inverted.
Check again to make sure this is really the case.

GB IN-OUT.png
 
Arrgh! My bad, sorry! I'm doing this around work so I think I must have got confused which side I was testing, those are actually L H L so all good :) Thanks for the EPROM file. Once I know which pins to test on the driver board I will do that....
 
I found the problem!! Completely by accident, I was probing PC3 when I slipped! The probe shorted pins 2 & 3 together, I noticed the HEX display acted like yours @RedFighter , so, I ran the AirDrive test and with those pins shorted it all works!! So now I need to work out where those pins go to on the board & hopefully find the broken trace!! So close.....
 
Pin 3 seems to be the issue, pin 2 traces back to the main game board OK, this is HIGH, so it goes pin 1 = H, 2 = H, 3 = DEAD, 4 = L etc etc. Pin 3 traces back to a resistor array & a diode(?) array. Those traces are fine....
 
I've made a new drawing for you.

Signal 1-8 DB.png


Here you can now find all measuring points of signals 1-8.

The signals coming from the gameboard and going to the inputs of PC3 and PC4 are in red color and the signals going from the outputs of PC3 and PC4 to the Sony chip are in blue color.
Now you can write tables again ;)
 
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;) I'll do it first thing in the morning. Any idea why it all works with those two pins shorted?!
 
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