Mikohn Yahtzee sg300 : low battery ram error

[MacGUYver]

Picked up a Yahtzee machine today, excited to get into it.  All there, has a ram error.  I turned it on, used reset key to clear it and goes back to battery error.  Will be soldering in new one tomorrow, too late today.  Not sure if the progressive works, but the top display is on an independent power source and that works.


One of my favorite machines was the sigma treasure tunnel, so far this seems similar.  Wish me luck, should be simple.

[MacGUYver]

Changed the battery, reset key switched through the ram errors, and it worked great.  Played eith it on and off through the day, did a few power cycles, and on thr last one the Yahtzee display didn't turn on.  Than, got  a bonus comm error.  Cycled power a few times, occasionally I'll get a few LEDs flash on/off, did itnlike ten times and got different ones a few times.


Opened the top, I'm getting 5v to the led, little red light is on showing power. Ribbon cable snug, reseating stuff didn't help.  There's onr capacitor on the board.


Not sure, is this how the led display would die, or sound more like the cap is going bad and not driving the board to turn oon the leds? A little stumped here, nothing changed from it working, and next power on it just doesn't.

[tollguy316]

 Hello. First off, congratulations on owning a yahtzee machine. It's a great game but unfortunately there's not many of them out there so getting help to fix them might be a little difficult At times. I own a Yahtzee machine and it works great also but the main issue I've come across is that when you move the machine a lot of times Connections of the top box or come loose. Its more of an annoyance than anything. But once you get the machine where you wanted it is generally pretty reliable. That's how I felt it's about 3 weeks ago when I turn my machine on and got the" bonus comm error ". My issue ended up being the power supply in the top box on the upper left. I replaced it with a brand new power supply which actually is the same power supply as the lower power supply for the Williams Dotmation slot machine. Hopefully this little bit of information can help you out. Good luck. Bill

[MacGUYver]

Yeah , was fun while it worked.  Just strange cause it seems like it's still getting power to the led board, just only a few will flicker on and then off.  I suspect some of the traces , will inspect more later. 


I see "large display" on rudysdeals (so probably can't even buy it..m) with the same boards, but it has like 9 of them when my led display only has two.  I'm gonna do a capacitor replacement and see if that gets me anywhere, and maybe jump a trace or two where they look a bit suspect.  Idk.


Anyone got a Yahtzee mikohn 341-012-90c set of driver boards/display? 

[MacGUYver]

Ok, pretty sure the board is getting power as it should, I now suspect the board before it.  It has a 5.5v 1f super cap.  I measured voltage on it while on, 4.2v.  not sure if I would get a perfect 5.5v on something like this, it's not a battery.  Should I expect 5.5v give or take?  Guess I'll order new one

[MacGUYver]

The top left power supply has no output!


Took it off, fuse is good.  The large cap is definitely charged (zapped myself so good!).  Pretty stumped, nothing looks burnt.  Will post pics later.  I'm terrible at troubleshooting power supplies


I have no idea what the voltage output is on this (no description at output posts).  Anyone got the powersupply for this, it drives the main board up top which drives the dice.  Or anyone got the voltage output?  I assume 5v, but one might be 12v cause it's on different traces.  Just not sure how to tell.


Edited since there's definitely power on the board, just dont know how to trace what's bad.  Everything s too cramped to do much also .  Could use a manual of someone has one for this Yahtzee top area (have the generic sg300 manual already).  All caps look fine, nfc.

[MacGUYver]

Some pics

[MacGUYver]

https://rudysdeals.com/index.php?route=product/product&path=44&product_id=3780

Found it on rudysdeals, but last time I ordered from them last year they had to refund me, never got the item after weeks.  So, before I try with them again, anyone got one?

[MacGUYver]

It's alive!


Thanks tollguy for pointing me to the artesyn power supplies.  After a bit of research and downloading specs, comparing them to old NLG archived posts of the sigma/Yahtzee power supplies, I found one on eBay for $24 with shipping.  I'll post more specifics later with a nice write-up.


Everything works, but now the bonus doesn't have sound (previously it was MAX sound, to the point where my wife was very aggro).  So during this fix i changed knobs to middle on the sound board.  I'll be maxing those out again. The only concern is this ps feeds that Board, so hopefully something didn't go screwy.  Regardless, it works and the bonus dice spin correctly and work, so I'm gonna call this mostly a win so far with minor fixes still required.


I think my mancave garage is looking pretty sweet, right?