4 Player Demo Derby Opto Boards... What's involved with rebuilding them?

ChompingQuarters

Well-known member
Joined
Oct 18, 2006
Messages
10,196
Reaction score
68
Location
Clinton Township, Michigan
4 Player Demo Derby Opto Boards... What's involved with rebuilding them?

At least one of my opto boards does not seem very responsive ... Then in test mode I have "some bleed" over to other players when steering Player one (bleed to player 3) same for 2 and 4... It doesn't seem to be interfering with game play.

I do have a few extra opto boards so I plan on swapping out some later to see if that is the problem. However, what's involved with rebuilding them? From the manual I'll say yes... But does 2 player demo derby use the same opto boards as the 4 player?
 
Can you put up pictures of the opto boards? I'd be curious to see what optics (opto interrupters) it uses. If it's the same as tron, or wacko. (these are different)
 
Can you put up pictures of the opto boards? I'd be curious to see what optics (opto interrupters) it uses. If it's the same as tron, or wacko. (these are different)

Here is a photo of my spare opto board...

257b39c5.jpg
 
Riptor has the 74ls49xx chips I believe. Those should be changed, and if you can identify some numbers on the optics maybe you can find replacements and change them as well.
that should make them work like new.
 
Thanks for the info. I'll contact Riptor.

The opto board is a Opto Switch Dual 1 (assuming it's the same as the one used on the 2 player).

Wondering if this is the correct one (scroll down a little bit)

http://www.actionpinball.com/elect.htm#optos

I am pretty sure the opto board (unit as a whole) is unique to each individual game.
The opto interrupters (optics) tend to be unique to each game as well I am finding. If you can rub off the dust and determine what numbers and letters are present, I am sure we can find replacement optics.
 
The photo looks like a funky dual opto, but I bet you anything you can install two QVE11233's side by side. Check dimensions and pinout against this datasheet (link).

If so I have a pile of them here in case you'll be around the Livonia area anytime soon and want to try it out.
 
Your optic board is pretty much the same as the tron one but layed out slightly different. That is the "deluxe" version of the board, A080-91794.
I sell the OPB822S dual optic switch which is a direct drop in replacement for your board.
http://www.twistywristarcade.com/bally-midway/647-opb822s.html
The 74LS491 goes bad on these quite often. I have these in stock also....very hard to find part.
http://www.twistywristarcade.com/74ls-ttl/634-74ls491.html

Thanks Mike... I'll be placing an order tomorrow.

The photo looks like a funky dual opto, but I bet you anything you can install two QVE11233's side by side. Check dimensions and pinout against this datasheet (link).

If so I have a pile of them here in case you'll be around the Livonia area anytime soon and want to try it out.

Thanks for the offer!
 
The opto boards are the same in the 4 player as the 2 player. There is a jumper on the PCB that was different on the two of them...but it is the same board. I believe Mystic Marathon may have used the same opto PCB. As far as rebuilding them...I never had one fail yet...and I have a bunch of them. I would say re-cap it, and clean/replace the sensor. As far as the "bleed over" , I believe you are going to see that no matter what. I spent a good amount of time chasing my tail on that "issue". Seems like it is just the nature of multiplexing the steering inputs. Players 1/3 and 2/4 are multiplexed. Check out the video I put up awhile back:
http://www.youtube.com/watch?v=JMynNLpnDW0

I had 2 or 3 people say their machine does the exact same thing.

-Mark
 
I think two tigers and wacko both use the "deluxe" opto board.
It would be nice to get a list together off all the games that used opto boards and which one they use. If enough games use the deluxe board I might reproduce those too.
 
I think two tigers and wacko both use the "deluxe" opto board.
It would be nice to get a list together off all the games that used opto boards and which one they use. If enough games use the deluxe board I might reproduce those too.

I can look at my kozmik krooz'r panel to see what it has. for the record the wacko trackball uses a different opto interrupter (optic)than tron. I haven't researched them to see if the values are different, but they are different parts altogether.
 
It would be nice to get a list together off all the games that used opto boards and which one they use. If enough games use the deluxe board I might reproduce those too.

I can add this to the MCR FAQ if people can help gather the info. I believe there are at least three different opto boards. But not to hijack this thread, i'll start a new one for gathering that info.
 
Voltage to the opto boards were about 5.1VDC... Right now it's about 5.5VDC and all the wheels seem responsive(ish)... Yellow and Green still seem a little sluggish / less responsive. What I find odd is that in test mode yellow green don't have readings (flip between 64 / 48)... Red readings duplicate to Green (Player 3) and Blue readings duplicated to Yellow (player 4)... However, if you put Player 1 and player 2 to "0" then all 4 seem to be reading independently.

Is 5.5VDC to the boards (PCB's and Opto PCB's) too high?

Either way I plan on purchasing 74LS491 and the OPB822S and swapping them out.

At least I enjoyed some Demo Derby tonight!!! :)

Bill
 
Voltage to the opto boards were about 5.1VDC... Right now it's about 5.5VDC and all the wheels seem responsive(ish)... Yellow and Green still seem a little sluggish / less responsive. What I find odd is that in test mode yellow green don't have readings (flip between 64 / 48)... Red readings duplicate to Green (Player 3) and Blue readings duplicated to Yellow (player 4)... However, if you put Player 1 and player 2 to "0" then all 4 seem to be reading independently.

Is 5.5VDC to the boards (PCB's and Opto PCB's) too high?

Either way I plan on purchasing 74LS491 and the OPB822S and swapping them out.

At least I enjoyed some Demo Derby tonight!!! :)

Bill

have you confirmed that OPB822S are what is currently on your optic boards?
 
Back
Top Bottom