I have a Genesis I'm going through, and I was hoping people could answer some questions. I haven't put in a ton of work yet, and have been working through the sys80 guide.

Here's what I've done so far:

- Verified all coils are good
- Verified all fuses are good
- Verified PS Board is good, outputting correct 5v to MPU

I am not getting the display to come to life when I connect it, so my question is basically:

Should I do ALL the ground mods (I am already planning to do them all) before going any further? Should I do it in steps and test as I go?

Also, if anyone has any tips on deciphering from the guide on what is only applicable to sys80b that would be helpful too - it's a little unclear (to me).

TIA

Sooo, where does one order bifurcated .156 crimp contacts now? No one seems to have them.

Assuming this will work as a sub:

https://www.greatplainselectronics.com/proddetail.asp?prod=350011-1

Hm, yeah Ed's site is showing obsolete (as everyone is) of the bifurcated.

I'm just looking for the crimps to add (2) 5v lines between the mpu and driver board. I have plenty of standard .156 here.

Paging ChrisHibler !

Thanks Topher.

Also wondering if anyone has ideas on where to ground the two chaser boards under PF to.

Sorry, I should have been more specific. I know where to ground to on the board side, but where to tie it into to? Somewhere that is easily accessed, and removable!

I'll probably leave them off for now, and re-visit down the road.

Well, I have now completed all of the ground mods and still no display text. Should I be assuming that the MPU is dead at this point?

Just did, getting 2.7V AC on pin 1...27V on pin 3...so something is amiss there for sure.

I actually haven't plugged everything in yet. I've gotten as far as the display.

On another note - where/what is A10?? I can't seem to locate it anywhere in the manual to reference where those connectors are.

Ah yes, now that I go back and look closely, page 31/32 are missing from my manual.

Can anyone post a photo of A12-J6? That would be on those pages and it's where display voltage originates.

Yes, I have that page. I was asking where physically in the machine A10-2 was - which is in the back box. The rest of the A10 (1&3) connectors are near the coin door.

What I'm missing is the transformer panel pages which are 31/32.

Battery stuff had already been done - memory cap installed in place of the battery and the board is clean. However, I did find the diode associated with that memory cap (that's supposed to keep the machine from trying to power up from the battery when off) tested bad. However, I don't think this could be the cause of anything I'm seeing??

I cleaned all of the edge connectors as I did the ground mods, and inspected all of the pins on connectors which looked clean and springy.

I'm away from my machines for a couple days, but I'll take a closer look at A1J2 when I return to them.

Took a look at A1J2 and it looks fine. Contacts are clean on both sides.

Kinda ripping my hair out and just wondering if I should order a new MPU??

What else can I test to see if that's my problem?

After installing a new mpu the game is booting and working mostly as normal. I will be getting the original fixed eventually as I suspect that it's bad RIOT chips or daughter card (probably both to be honest). I do still have some issues though:

1. I seem to have lost the controlled lamps during game play. They work during attract, but I would say around 95% of them do not work during the game.

2. What kind of fluorescent starter do these need? I ordered one from Marco which it claims is matched in terms of size/wattage of the lamp, however both the starter and the lamp flickers when I power up.

3. Lane change is not working. Switch appears gapped correctly and I cleaned the contacts.

What I am most confused by is that all the lamps work during lamp test.

Looking into it further and re-running lamp test makes me think it’s definitely in that connector. There are actually about 10 controlled lamps not coming on during lamp test, and they’re scattered between flip flops. I’m going to start testing the transistors.

Included in those 10, are ones that should be on at the top of a new game.

Welp, there you go. Bunch of bad transistors.

Good stuff, thanks for that link.

I am curious if anyone has insights into why these various transistors could have failed. I can say definitively that when I installed the new MPU, at least some or all of these transistors had not failed yet. They failed during a play test.

My current plan is to get a new driver board, and replace the failed transistors on the original board, but I would obviously like to prevent the same thing from happening again.

I have not done this...haven't heard about that...

Here's what I have done:

- ground updates throughout
- replaced MPU
- cleaned all the edge connectors
- verified consistent 5v to mpu
- reflowed headers on power supply
- added extra ground + logic to interconnect

I'm pretty sold on replacing the driver board so I can have a working game and then replace those transistors in the next couple of weeks. Just trying to maybe track down what went wrong so it's not repeated.

Well, all of the fuses are correct. I replaced the driver board with a new Ni-Wumpf and am getting...the exact same behavior. SO - I must assume that it is the interconnect cable between MPU and driver?

What I find very odd is when I had the original driver board installed, I was testing the transistors by grounding them to the cabinet and the lamps that were not working were not working under that test...?