Stern Star Trek IR switch glitch - help!

[Matt BRU]

So my STPro has started to occasionally have what appears to be a switch issue. Some games it doesn't happen, but then others it happens and I have to switch the power off to the machine, this is the issue:

Mid game, it can start scoring multiple hits on different switches in very quick succession, almost in a machine gun like stutter, it seems to affect warp ramp switches, left ramp, right ramp and centre lock switches (image attached to show affected switches in test mode). Like w-w-w-w-w-w-w-w-w-warp like 4 times a second and keeps going so I have to switch the machine off.

I recently had a trough opto switch error that basically thought the ball had drained when it was still in play - I re-seated the opto 2-pin connectors but thought to mention in case it could be related.

Someone also mentioned to try unplugging/plugging every 2-pin opto connector under the playfield - I have done this twice but it hasn't fixed it.

I have also checked the IR beams and they seem to be all in line. I feel like it could have originated from the warp ramp entrance IR beam or something, it always seems to warp callout w-w-w-w-w-w-w-warp when it starts, but in switch test mode it clearly affects all IR switches.

So I'm now stuck as I can't seem to diagnose or fix this, has anyone else experienced this, or ideas on how to fix it? Any help much appreciated!

 

[kevlar]

I've had phantom warp ramps on mine, sometimes reconnecting the optos stops it for a while. The latest fix that seems to have worked was securing the warp ramp exit opto that's behind the playfield back board. It was slightly loose. Not sure about all optos giving faults though other than to suggest reseating connectors in the backbox.

 

[Matt BRU]

I've had phantom warp ramps on mine, sometimes reconnecting the optos stops it for a while. The latest fix that seems to have worked was securing the warp ramp exit opto that's behind the playfield back board. It was slightly loose. Not sure about all optos giving faults though other than to suggest reseating connectors in the backbox.

Okay thanks i'll give that a go! Didn't think to check the backbox opto connections - I only checked the 'under playfield' optos. That's if I understood you correctly...

Is it obvious which backbox opto connectors relate to the warp ramp?

 

[kevlar]

Okay thanks i'll give that a go! Didn't think to check the backbox opto connections - I only checked the 'under playfield' optos. That's if I understood you correctly...

Is it obvious which backbox opto connectors relate to the warp ramp?

No but I guess they feed back to the switch matrix connectors, rows and columns. They're labeled up on the large board.

 

[Sven Normansson]

had that right out of the box, it's the opto at the top of the ramp.

 

[Matt BRU]

had that right out of the box, it's the opto at the top of the ramp.

do you mean the IR switch at the entrance to the warp ramp? Were you experiencing all IR switches going in rapid succession? thanks for your help!
How did you fix it - adjust the IR beam transmitter/receiver?

 

[Sven Normansson]

at the top, just before it goes into the backboard.

 

[kevlar]

Warp ramp exit opto is behind the backboard, at least it is on mine. Have to pull playfield forward to get to it.

 

[windoesnot]

The joys of Stern optos:

Reconnect all opto plugs on the board and also the power to the board. This worked on my WoF when an opto kept registering

Check the optos are perfectly aligned. The fact that flipper vibration causes them to trigger likely means they are slightly off (right ramp on my old ST used to do this)

Clean the optos themselves if needed

 

[Matt BRU]

Great stuff! Thank you all, much appreciated. Will try a few of these things tonight

 

[stoptap]

The joys of Stern optos:

Reconnect all opto plugs on the board and also the power to the board. This worked on my WoF when an opto kept registering

Check the optos are perfectly aligned. The fact that flipper vibration causes them to trigger likely means they are slightly off (right ramp on my old ST used to do this)

Clean the optos themselves if needed

what do you mean ‘used to’ ?