With the WhoDunnit's slot reel motor being my main suspect, I pull the whole slot machine assembly off the machine for closer look.
As it's on my desk, it's very clear just how hosed the old motor is. Without power, the steppers here should spin freely. This bad one barely moves and feels all crunchy inside. Most likely its bearings are FUBAR.
So here's a sped of version of the half an hour it took to replace whole thing. The slot machine assembly has 3 identical reel sub-assemblies in it. They come off with four screws, after which the reel has to be separated from the motor and finally the motor from the support bracket.
As this is just a generic stepper motor, I need to make a connector that fits the pin's stepper driver board. Fortunately that's just 4x 0.156" Molex KK pins and then vacating the old housing and stuffing these new ones in.
The reel test shows the new motor running as expected with no extra noises or other apparent issues. As I return to the attraction mode, the machine does a self-test on the reels, homing stopping them at bar-multiball-clue. For the owners of this game it's an easy way to verify it works.
#pinball #repair #retrotech #mechanism
Ari [APz] Sovijärvi
npub1hz…xwwp4
2026-10-21 00:27:18 UTC
Author Public Key
npub1hzy4v5a5zxtc5xd6sse5hw3c7a3nt9ue37x42nl7skyfhe9jg0msyxwwp4Seen on
wss://relay.momostr.pinkPublished at
2026-10-21 00:27:18 UTCEvent JSON
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"content": "With the WhoDunnit's slot reel motor being my main suspect, I pull the whole slot machine assembly off the machine for closer look.\n\nAs it's on my desk, it's very clear just how hosed the old motor is. Without power, the steppers here should spin freely. This bad one barely moves and feels all crunchy inside. Most likely its bearings are FUBAR.\n\nSo here's a sped of version of the half an hour it took to replace whole thing. The slot machine assembly has 3 identical reel sub-assemblies in it. They come off with four screws, after which the reel has to be separated from the motor and finally the motor from the support bracket.\n\nAs this is just a generic stepper motor, I need to make a connector that fits the pin's stepper driver board. Fortunately that's just 4x 0.156\" Molex KK pins and then vacating the old housing and stuffing these new ones in.\n\nThe reel test shows the new motor running as expected with no extra noises or other apparent issues. As I return to the attraction mode, the machine does a self-test on the reels, homing stopping them at bar-multiball-clue. For the owners of this game it's an easy way to verify it works.\n\n#pinball #repair #retrotech #mechanism\nhttps://some.apz.fi/system/media_attachments/files/117/476/058/517/395/786/original/32764e66da446c95.mp4\n",
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