Bally MPU Alltek vs original vs nvram.weebly.com

[AlanJ]

I've been using Alltek replacement boards in my Bally SS machines, and up to press, have been perfect. I bought a couple of nvram.weebly.com boards a while ago and never got around to using them - until recently.

My 8 Ball deluxe was refurbed last year and I haven't played it that much to be honest, until the day before the league meet, when it stated playing up - it kept hanging up. I thought I'd fixed the issue, but it failed on the day of the meet.

I did some extensive testing yesterday and realized it was hanging up and showing the red led for "over voltage". Sure enough the SDB board with the 5v regulator is a bit out of spec at 5.35v. So I swapped it for another SDB board - same issue, again turns out this 2nd old SDB board is also a bit out of spec - 5.3v. (spec is max 5.25v) The Alltek board hangs up after a while. I swapped in an old MPU board - fine. I also tried my nvram.weebly.com board - also fine.

Conclusion - the Alltek board is a bit voltage sensitive. The nvram.weebly.com board is more in line with the original boards, doesn't much care about a bit of over voltage & works out a bit cheaper usually (depending on import charges). So its nvram.weebly.com from now on.

I'm going to replaced the LM323K 5V regulators on the 2 SDB boards that are out of spec - parts ordered. Also decided to order nvram.weebly.com SDB board as well, so I have a modern spare for testing purposes.

 

[stevebm1]

I have had the same issue in the past myself,I also swapped out the sdb and it solved the problem

 

[AlanJ]

I have had the same issue in the past myself,I also swapped out the sdb and it solved the problem

That's interesting to know Steve, thanks.

 

[myPinballs]

Altek boards have always had 'an issue' with the 5v voltage input. I think that is actually by design to be strict on it. A drifting 5v line or one that gradually get higher over the day wen switched on has the potential to cause problems. The solution is to rebuild your power driver board 5v section fully. Problem solved usually. My personal view is they maybe are alittle too strict for 40 plus year old games and nos old linear parts even. 5.35v isnt that much of an issue when you think of the old connectors and parts generally. I think it may come down to the fact lots of 74 logic ics quote a max rating of 5.25v for operation, though in fact this can be quite bit higher before they die or cause an issue as proved by the fact originals still run fine.

You could see the altek stopping to boot as actually a fault warning for the power driver board and that is another reason altek boards are great. Always take a rebuilt power driver board with you to a remote repair though if installing an altek to an unknown machine, otherwise you look pretty silly when the new game board you put in fails to turn the game on...

 

[Deleted member 2463]

Weebly boards are superb as You can also run your own software on them - this has fixed some bad bugs in nine ball and added some cool features in other Stern games.

new boards coming from altek and weebly soon though!

 

[AlanJ]

Altek boards have always had 'an issue' with the 5v voltage input. I think that is actually by design to be strict on it. A drifting 5v line or one that gradually get higher over the day wen switched on has the potential to cause problems. The solution is to rebuild your power driver board 5v section fully. Problem solved usually. My personal view is they maybe are alittle too strict for 40 plus year old games and nos old linear parts even. 5.35v isnt that much of an issue when you think of the old connectors and parts generally. I think it may come down to the fact lots of 74 logic ics quote a max rating of 5.25v for operation, though in fact this can be quite bit higher before they die or cause an issue.

You could see the altek stopping to boot as actually a fault warning for the power driver board and that is another reason altek boards are great. Always take a rebuilt power driver board with you to a remote repair though if installing an altek to an unknown machine, otherwise you look pretty silly when the new game board you put in fails to turn the game on...

Agree - I need to fix the dodgy SDB boards. They seemed to go out of spec over time, ie ok for first 5 mins, then the voltage gradually increases, in attract mode seemed ok, would stay ok for 2-3 hours, but then as soon as a game is started it would hang up.

I tried an experiment to replace the 5v with a totally different 5v power source, but it didnt work - got lots of flashing score displays - so maybe messed up the display interrupt generator or the zero crossing? but not sure why. Anyhow will wait for the new parts to turn up and do it properly.