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Just got my first PCBs! .. and desperately need some experienced advice!

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proto

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Hi guys!

Having just written this I see just how long it is! Apologies in advance!

New to arcade PCBs and in desperate need of some experienced help :)

Got a dozen or so MVS games and had no issues whatsoever. I recently bought 3 PCBs and the problems just pile up. It may be I'm missing something or the PCBs have issues. They were all sold as tested and working (and I have no reason to believe otherwise)...

Here goes!

Patient 1 - Fantasie II
There are horizontal lines across the screen always.
Other than that all normal...
(photo attached)
Fantasie2.jpg


Patient 2 - Pinball action
Now... this one may be my doing..
This isn't a jamma board but did come with an adaptor.
Thing is I plugged in the jamma harness a couple of times the wrong way round before figuring out exactly how it should be plugged in.
It has never powered up (green screen) so either it was faulty initially or I fried it myself.
Is it likely that plugging in the jamma harness the wrong way fries a board?
I attach a photo of the right way to plug it in.

Pinball - Copy.jpg


Patient 3 - World Rally 2
1) When playing the game some shapes / broken pixels appear every now and then (see pic).
Whats interesting is that these seem to stop happening after around 10 minutes of the board running. Is there such a thing as boards needing to warm up?!
2) All white areas on the screen have a pretty strong green tint. I could correct this from the CRT i guess (haven't tried) but the screen is well calibrated for the MVS (a dozen games) - is this normal or could this be an issue?
3) Also, in case it helps... sometimes when I connect it up it just doesn't work (green screen). I unplug the harness, reconnect and it works.
4) Once the game stopped responding (video was OK but no reaction from the joystick/buttons/coin).
5) Once the game just went from all OK to green screen

Here's quite a long video of all this stuff:

World rally 2 - Copy.png


THANKS!!
Proto
 
Hey man, welcome to the forum!

i still consider myself quite the noob, at least compared to the sheer knowlege residing in this forum, so please take my word with a grain of salt.

patient 2: if you've connected the jamma edge the wrong way around the chances are pretty high that you at least did some bigger damage to it. But if Thats repairable i really can't tell.

Patient 3: if the green tint is on this board only, the error should probably be on the board itself, i would look what state the capacitors are in, perhaps there's one on the colour signals thats gone bad. with the corrupted parts of the graphics there are people far more competent than me here...

patient 1: are these horizontal lines only withthis game? perhaps it's also a cap issue?
 
MoppelTheWhale said:
Patient 3: if the green tint is on this board only, the error should probably be on the board itself, i would look what state the capacitors are in, perhaps there's one on the colour signals thats gone bad.
Click to expand...

His Fantasie board pic looks very green to me too.
 
nem said:
His Fantasie board pic looks very green to me too.
Click to expand...
Hey Nem - that's a good observation... yes, it is. I'll show my noobness by asking this: I've calibrated my CRT for my MVS (using the MVS motherboard pattern) and it is perfect (whites are white etc). Could it be that I need to re-calibrate the screen for PCBs (or even, for each PCB?)
 
You usually need to make minor adjustments between PCBs with brightness and sometimes colour, but nothing that drastic.

That one PCB definitely has something funky going on to give it the green tinge.
 
Hey guys, spent a couple of weeks on the three boards and have some progress to report, although none of them are 100% yet :(

Patient 2 Pinball action
Great news here! I found two unsoldered wires on the jamma adapter and also a capacitor that was unsoldered and fixed them. Board loads perfectly and, in all respects but one works great. The only problem... no sound! I'm hoping I'm missing something here... here's what I've checked:
- the 12v power is connected correctly
- the sound+ and sound- pins on the jamma are getting power (I measured +6.5v on both of them when connecting to ground, is that around normal?)
- I set switch 8 on switch1 to ON which activates demo sound (didn't find any other switches that relate to sound)
- I do get sound with other boards no problem
- I've looked all over the board and don't see a volume pot anywhere... how do you control sound volume I wonder?!
- I've found thing strange little component (vertical square with hole in the middle)... any chance this has something to do with this, can I rotate this?

unnamed (1).jpg


Fun fact: None of the buttons seemed to start the game after inserting a coin so I thought there was an issue. I then read up on the edge pin out and realised that whoever made the adapter has wires the player 1 controls to the joystick instead of the buttons! So, stick down to start game, up to launch ball, left and right for the paddles. Weird!

Patient 3 WR2
Video 1: https://vimeo.com/494762972
Video 2: https://vimeo.com/494762935

Not so good news here I'm afraid... The board keeps on being super weird! Here are some of the symptoms:
- Doesn't power on sometimes. If I restart power a few times it eventually works (see start of video 1)
- Boxes of broken pixels may appear at random points (see video 1 00:35 and 01:00 and video 2 at 1:46)
- The physics of the game go weird sometimes! The car may fly across the screen, may get stuck when it shouldn't (a small example of this on video 2 at around 01:04)
- It may go straight to green screen while you're playing (see video 1 01:02)
- It seems to get stuck on the game over screen (it shows a realistic photo when you lose... no button will make the game move past this, video 2 at 02:00)
- This is the best one: Pressing one of the player 2 buttons makes the graphics on the entire screen go crazy (video 2 at 02:20)!

I suspected voltage issues and played around but didn't see a difference. I gave 5.25 at the jamma edge and tested a bunch of the chips all over the board and it seems they get 5.20 or so. I even took the voltage up to 5.3 but no difference.
I wonder, is there any way my power supply can't give enough amps? Does this happen with arcades? I see my PSU is what appears to be a standard arcade PSU... nothing special

Patient 1 Fantasia 2
This continues having the same issue...:
- Horizontal lines
- White glow on the right

IMG_8470.jpg


Someone suggested I check voltage on this board too, I haven't yet... will do and report back.



Finally, in the original post I mentioned that a couple of the boards seems to give a green hue to the whole screen. This was just a monitor calibration... all good!
 
proto said:
Patient 3 WR2
- This is the best one: Pressing one of the player 2 buttons makes the graphics on the entire screen go crazy (video 2 at 02:20)!
Click to expand...
IIRC it's because 2P inputs are used to connect a steering wheel so by pressing a button you actually create a short.
 
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Reactions: nem
Hey guys - great news! Pinball action is back in action. Seems like someone had worked on the sound section previously, replacing the usual volume pot with that black square I showed in the photo. Rotated the inside and volume is back :) Happy days!

One down, two to go!
 
Apocalypse said:
IIRC it's because 2P inputs are used to connect a steering wheel so by pressing a button you actually create a short.
Click to expand...

Correct. VCC for the steering pot is on pin c (25 solder side), so 4th button on the 2P side. You're shorting it to ground whenever you're pressing the button.

You need to wire the game up to a second cab if you want to play a two player game.

Manual is here:

https://www.gamesdatabase.org/Media...orld_Rally_2-_Twin_Racing_-_1995_-_Gaelco.pdf
 
nem said:
Correct. VCC for the steering pot is on pin c (25 solder side), so 4th button on the 2P side. You're shorting it to ground whenever you're pressing the button.

You need to wire the game up to a second cab if you want to play a two player game.

Manual is here:

https://www.gamesdatabase.org/Media...orld_Rally_2-_Twin_Racing_-_1995_-_Gaelco.pdf
Click to expand...
Makes sense! Thanks! I was aware of the way it works with two players and two cabs ("twin racing"!) but didn't expect that kind of shorting behaviour. Live and learn :) Thank you
 
Hey guys, great news! three out of three patients are working 100% now!

Fantasia 2 was having video ground issues. I connected jamma pins 1/2/A/B to video ground and all video issues were solved
WR2 was totally my fault... I was giving 5.15v while it wanted exactly 5v. With 5v all the weirdness goes away!
And pinball action as mentioned above just needed adjusting the volume pot

Happy days!
 
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