MCR Troubleshooting.

Its not booting. Try pressing the red reset button and see if anything changes.
 
That's about all i can tell you - its not booting. Could be ram, rom, reset circuit, addressing, buffering, etc, etc, etc.
 
Chances are it's the Tantalum Capacitors. I replaced all of them on my Kickman board. The first time I powered it up I had smoke coming from my board too.

Look in the parts list and find anything marked TANT and replace those. Standard Axial Electrolytic Caps will work just fine.

This is the video board:
View attachment 608199

This is the CPU board:
View attachment 608200

This is the I/O board:
View attachment 608201
Is this something that should be done with every MCR game?
 
That's about all i can tell you - its not booting. Could be ram, rom, reset circuit, addressing, buffering, etc, etc, etc.
Update; I swapped out the switcher adapter to the original power supply board and it booted right up. I'm thinking the adapter is bad, because the switcher voltages are good. I unplugged the connectors a few times to make sure it wasn't that. Very strange. I'm glad it works again! The bad part is I lost my old HS's, tonight's test game was over 100k. Thanks for your help.
 
@cdjump
Thanks for this tutorial. I have a solar fox cocktail where the screen is just blank - not blue, but kind of static.
Blank Screen Video

I followed your instructions and these are my results:

MCR II Sound IO
5v @ capacitors : I get 4.7v
12v @ tantalum caps: I get 12.3
Vbatt I get 6.3-6.4

/Reset - Pin 26 on the Z80: With my meter, I get 5v, but it shows drops to 3.6 here and there.

So I put the logic probe on pin 26 of the Z80 and I get the tester showing logic is changing?
My understanding is it should be logic high and at 5v so it seems I should just get a high tone on the probe? ( see attached video)
This machine has an arcade shop midway power supply adapter that is probably ~15 years old. It looks like there is a transistor on the line feeding the violet wire that is the reset line.
I happen to have a new power supply adapter on hand, that I could swap, but I don't want to just start throwing parts at this without knowing what the deal is.
Thanks for your help!!


Logic Probe Video
 

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If the /reset line is pulsing, the 3 pcb stack isn't booting, and the watchdog is barking trying to force the cpu to boot the game.
 
Thanks so much for the reply.
Do all my other voltages look ok, or where do you think the issue is?
 
The main pcb stack isn't booting. It could be ram, rom, z80, etc. Your board needs to be repaired.
 
Spy Hunter lamp driver issues-

12v is supplied to the lamps themselves through the 2.2 ohm resistor on the lamp board. You should see 12v at pins 5 and 6 (that goes straight to the bulbs), then the grounds are controlled through the uln2068s. That resistor (R19) is famous for opening up, and if there's no current through it (ie, the cpu isn't calling for lights), unless its completely opened, you will see 12v there, but, when the uln2068 completes the circuit, there's so much resistance that the bulb doesn't illuminate.
Long story short, i replace that resistor (R19 2.2ohm, 1watt) with a 2.2ohm 3w resistor on every lamp driver i work on. Its overkill, but its one less problem it'll ever have again. You can bypass the resistor temporarily by putting a jumper wire across it. Don't leave it that way, as that resistor is there to dim the bulbs a bit to keep the heat down and the bezel from flaking. If you bypass R19, and the lights work. Its R19.
 
I hesitate to post it here, but...
My Tron boots up, gives a little squelch, and goes through attract mode normally.
When you start a game, it squelches then blows the unregulated 12V fuse.
Where should I start?

I've got Journey & Spy Hunter, too, and thought about swapping in a Dual Amp W/Mixing pcb as a test. I just haven't made an adapter yet.
 
My Kickman has scrambled sprites.
I assume it's some sort of ram problem in the video board?
 

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Not sure if this is a red herring or the sign of an issue, but maybe someone can sanity check me.
On my problematic Kickman board set if I measure resistance across the 5v and ground rail on the 3 boards disconnected.
I get like 1.7k ohms on the Video and SSIO boards.
but on the CPU board I'm only getting 200-250 ohms.
I checked a working Tron boardset that I have and the resistance on the CPU board is closer to the 2k ohm range.

Is it possible I have a short somewhere that pulling that resistance down?
or is the difference between the MCR1 and MCR2 boards that big?
 
On Spy Hunter dipswitch b3 pos 4 on sets the pcb to 1 coin/credit default vs 2 coins.
I've never found any mention of that in a manaul or service bulletin, but i've verified it on 2 different pcbs now.

Full B3 dip switch settings-
Spy Hunter B3 dip switch settings

off / on
1 1min 30 timer / 1 min timer
2 no attract music / attract music
3 1 coin meter / 2 coin meters
4 2 coin/credit / 1 coin/credit
 
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@cdjump I am chasing cause of f1 fuse blowing on PS board in Spy Hunter. It boots and runs for 10-15 seconds.
- It happens in with 2 different PS boards and they both work fine in Tron so unlikely it is the PS board.
- I have likely narrowed it down pcb stack as I have everything (cheap squeak, lamp, coin door, etc) plugged in except pcb and it doesn't blow.
- caveat, not sure the lamp board is doing anything if not activated by pcb.
- however, with just pcb plugged in, it still blows so back to pointing to pcb.
- I then added 1 amp load on 5v line and it doesn't blow and ripple voltage is low on +5v line. I could add more artificial load too.
- Disassembled the board stack, measured resistance between +12 and +5v rails to associated gnd; there are no obvious shorts on either rail.

Am I missing something?
 
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