What's new
Pinball info

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Jokerz drop target problem

PUP

Site Supporter
Joined
May 13, 2015
Messages
329
Location
Southport
A strange one here, iv noticed that one bank on the left it only workes proper if they fall bottom middle top, if they fall any other combination it takes about 5 seconds to register. The fault is on the drop target board itself and i have tried changing the lm339 chip but still the same, could it be a faulty opto although it works fine if they fall in order? Iv noticed the board at fault is slightly different from the others but im sure its not had that fault all the time iv had it. Any help?
 

Attachments

  • 15890341350603227340179885214747.jpg
    15890341350603227340179885214747.jpg
    65.3 KB · Views: 30
  • 15890341617294381866112376245156.jpg
    15890341617294381866112376245156.jpg
    115.5 KB · Views: 28
Do the targets completely drop down in any sequence ? May be just be a strip down and clean also make sure the washer are on the right order.
Also noticed one of the bank target board is missing washer and clip that also might be a reason why it's playing up
 
Also check for dry joints on the header pins. I had a problem on a robot years ago that it had a fault but only when it did a certain movement. It turned out to be a dry joint and it only became an issue when the robot did a specific movement.
 
Did this to my Diner it works but not perfect
Mostly likely dry joints as @stoptap said !!
 

Attachments

  • 15891089867541318695359.jpg
    15891089867541318695359.jpg
    101.7 KB · Views: 19
thanks for replies, il have another bash with it at the weekend. yes drops fall all fine its not mechanical. its def on that board as i changed it for the board on one of the other banks and it travelled. just so strange how it works fine if they drop in bottom-middle-top sequence but other ways cause problem thats why i thought it had to be the lm339 chip
 
Rebuilt a few of these DT assemblies, usually as they're gunked up. Millwax was overused on the last table. Haven't seen this fault before though. I would reflow solder on the IC socket and check continuity before refitting chip.
 
Back
Top Bottom