Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Semi related I used the LD-274 IR LEDs to fix my dynamo air hockey table tonight. It needed new IR LEDs as well, and I didn't know what the original spec were. I saw in another thread someone suggested Radio Shack 276-143. I looked those up and their peak wavelength is 940nm. The LD-274 is 950 nm. Of course they're going to output a spectrum, not just the one wavelength. Nonetheless they were good enough for the IR receivers in the score sensor pcb to detect. The old ones were emitting, but weak. I think 940nm is kind of a standard for IR stuff, and unless there's a reason to deviate it's safe to assume everything will work with it. IR is outside human's visible spectrum, but often times they will emit some visible wavelengths or at least something that a camera on your phone will detect. I will use a picture or even just the viewfinder to see if there's any light shining while the sensor PCB is powered. It turns out these LEDs are on the whole time whether you're in a game or not. No wonder they burn out.I fixed the prize sensor board. I did a few things but ultimately I believe the fix was to replace the IR LEDs with new ones. I used the same ones I use for my LAI Stacker prize sensors. I guess it just needs an IR signal, it doesn't necessarily need to be exactly the same LED that they used originally? Or they just happened to use the same value ones as LAI?
I also reflowed some things, checked the pot, replaced the capacitors, and fixed one broken trace. I replaced the capacitors with higher voltage ones I had on hand, and then I couldn't get it back into the case, but I wanted to test it to see if that fixed the problem I was seeing. I saw no change so I put the original capacitor back in so that it would fit in the case. When I removed the 470uf cap the second time it lifted the pad/trace. So that's why I had to redo a trace... I also tested the little darlington transistor array. I thought the bigger transistor was bad, but when I looked up the datasheet the base was pin 3, instead of pin 2 like I was expecting.
Once I had the prize sensor back in the machine I noticed that it was needing a slight alignment for better results. I put a nut under the bottom 2 screws to raise the bottom up a little and point it downwards a few degrees.
Now I think I have everything working, but if I set the voltages too high for the claw it will occasionally fail and reset. Or just die. I am guessing that the power supply is failing, but not quite dead. Perhaps it needs a recap? Or I might just buy a new one and call it a day?


The play till you win setting is done through dip switches. Do you have the kind with 1 VR or 3? Take some pictures of your PCB or the volt meter? If you have the original roll down coin mechs they have a small switch on the back of them? you use those to go into the voltage adjust mode. DM me if you need more help.Complete noobie here I just got one of these that wasn't working and was able to figure out that it just needed a fuse replacement to get it working again! I am unsure how to adjust claw strength, it should be set on winner every time but the claw seems a bit weak. Any advice on where to start is much appreciated.
View attachment IMG_20230304_092814.jpgThe play till you win setting is done through dip switches. Do you have the kind with 1 VR or 3? Take some pictures of your PCB or the volt meter? If you have the original roll down coin mechs they have a small switch on the back of them? you use those to go into the voltage adjust mode. DM me if you need more help.
So you have the 3 VR style. One is for initial grab strength, two is rising claw strength, three is carry home strength. You can adjust them blindly or go into the setting mode with the switch on the coin mech.View attachment 649196
I noticed I can change some claw settings with these knobs what would this part be called? Where they are set now it will win everytime with light objects but I am unsure how to adjust any settings without just blindly turning the knobs.
I was going to DM you but it wasn't letting me add pictures to the message. Thank you for the reply
I have the same problem with mine. Reading through forums to see if there are similar cases before I go through the machine since it is on location 2 hours away. In the past I have had issues with the wiring between the claw coil and the carriage; lots of flexing over the years broke the wire internally. I will ohm-out the coil at the carriage while flexing the cable to see if there are any intermittent opens. I that is good I plan on testing the second of the three VRs to rule that out.Awesome that info and video are extremely helpful! Thank you for that... I've also noticed every once in a while the claw fully opens for a split second right before it gets to the top and makes its way home, would that be related to these voltage settings?