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Super Monaco GP Airdrive

Thanks @sega_man and I'm glad you read my report. ^^
Unfortunately I don't have a schematic of the additional soundboard.
For my SMGP Deluxe project I have been looking for the Sound pcb 837-7000 for several months.
Hard to find, hope someone has one for sale someday...

if i had the schematic i could try to build a pcb. :P
I'm really grateful for any help
 
If you can get the original capacitors, use these.
You can use these X7R axial capacitors as a replacement
C410C223K5R5TA
 
RedFighter said:
@sega_man
First I would measure the supply voltage at the potentiometers for the steering, gas and brakes.
There should be GND and +5V on the outer pins of the potentiometer.
If that works, check out IC166, a 74HC4051 analog multiplexer. The analog signals go straight to this IC.
Possibly check the lines up to the pins, maybe something is smoked there or the line is broken.
Click to expand...
It was MUCH simpler! Just a bad connection between the loom & the filter board. I haven't had time to have a proper go at it today. I should have most of tomorrow on it so hope to get the machine back together & playable! I think the filter board or the wiring has issues as the picture goes if I move anything! I've reflowed the filter board so coud just be corrosion on the connectors...or a broken wire(s)!! The sound board is working :) I swapped the sound wiring plugs around to test it.
 
Started on the capacitors...
20221204_141649.jpg


20221204_142721.jpg
 
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OK, what with Christmas, birthday, work & the World Cup I haven't had much spare time! The connector pins on both sides of the filter board were corroded, they cleaned up OK. However it looks like the actual connectors on the loom are also corroded! Is there any "magic spray"(!) that can clean them up or is it a case of replacing each connector? (type/supplier?). The only input now not working is the downshift, I haven't had time to check the wiring back to the board yet.

Back to the original board......
20221209_131811.jpg
 
RAM at IC22,23,31 & 32 is OK (tested in the other board). LS chips at 24,25,26,27,33,34,35 & 36 are all OK (tested in the other board). It is also now claiming 108 is bad!

My continuity checking went as far as this : -

(RAM address lines)

RAM pin     IC35  IC34
2           12    
3                 2
4                 4
5                 6
6                 8
7                 11
8                 13
9                 15
10                17
21          7
23          9
24          5
25          3

(RAM DQ lines on IC31 & IC32)

RAM pin     IC25
11          9
12          8
13          7
15          6
16          5
17          4
18          3
19          2

(RAM DQ lines on IC22 & IC23)

RAM pin     IC24
11          9
12          8
13          7
15          6
16          5
17          4
18          3
19          2

Logic probe findings : -

All RAM
1 DEAD
2-10 HIGH
11-13 DEAD
14 LOW
15-19 DEAD
20-21 HIGH
22 LOW
23-25 HIGH
26 LOW
27-28 HIGH

IC 24
1 HIGH
2 -9 DEAD
10 LOW
11-18 HIGH PULSE
19 LOW PULSE
20 H

IC 25
1 LOW
2-9 DEAD
10 HIGH
11-18 HIGH PULSE
19 LOW PULSE
20 HIGH

IC26
1 LOW
2-9 HIGH
10 LOW
11-15 DEAD
16 PULSE
17-18 DEAD
19 LOW
20 HIGH

IC27
1 LOW
2-9 HIGH
10 LOW
11-18 DEAD
19 LOW
20 HIGH

IC33
1 LOW PULSE
2 DEAD
3 HIGH PULSE
4 DEAD
5 HIGH PULSE
6 DEAD
7 HIGH PULSE
8 DEAD
9 LOW
10 LOW
11 LOW
12-18 HIGH
19 LOW PULSE
20 HIGH

IC34
1 LOW PULSE
2 DEAD
3 HIGH PULSE
4 DEAD
5 HIGH PULSE
6 DEAD
7 HIGH PULSE
8 DEAD
9 HIGH PULSE
10 HIGH
11 HIGH
12-18 HIGH PULSE
19 LOW PULSE
20 HIGH

IC35
1 LOW
2 HIGH PULSE
3 DEAD
4 HIGH
5 DEAD
6 HIGH
7 DEAD
8 HIGH
9 DEAD
10 LOW
11 HIGH
12-18 HIGH PULSE
19 LOW
20 HIGH


IC36
1 LOW
2-9 HIGH
10 LOW
11-18 HIGH
19 LOW
20 HIGH

Anything stand out to anyone? I can see RAM @ IC9, 10, 38 & 39 in this area, worth socketing & swapping? I can't help but feel it's a bad trace.....but getting close to throwing in the towel!
 
I would just like to say you have done an amazing job with this and come a long way.
It does sound like a bad trace, as you have pretty much tested everything else.

Cheers Justin
 
OK, more problems! I've done a video of the loud audio hum, this comes out of all speakers, it was like this back in '96 when I first got it! Secondly, the monitor has started playing up, the top of the picture folds in on itself, any idea's? Thanks ;)

The monitor issue is intermittent, sometimes it's perfect, have tapped gently around the PCB but no change, dry joint rather than failing component?
20221215_142123.jpg


20221215_142230.jpg
 
You think the hum is a ground wire somewhere that shouldn't be? Not done anything on the monitor yet, is there a kit available for these? Cheers
 
is that white sticker saying "ms8-26se" ?

I had a similar ground noise on a cab and my audio friend kept repeating "cut the ground! cut the ground!" ... until he did it himself and the sound stopped at once.
it's a secondary and easy problem to isolate for you after all the stuff you've gone through ;)
 
OK, thanks ;) I've found cap kits but all seem to be in the USA, guess I'll have to make a list & see if a supplier in the UK has them. Thinking about what it is doing, I recall a bad cap causing the same on another monitor. The picture is great with no burn in so deffo worth a recap :)
 
MS8 are really nice monitors indeed. The one in my Virtua Fighter is one of the best I have. I am pretty sure you can get your caps not in the US.

Sound: right! this game has an additional sound board ? got some pictures?
 
Yep, there is an extra sound board which plugs into the bottom of the PCB....

20221215_160751.jpg


Main PCB sound connectors.....

20221215_160801.jpg

All go back to a single connector on the filter board....

20221215_160808.jpg


Finally, the amps....

20221215_160952.jpg
 
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