Body Capacitance??

[Sako-TRG]

So, my HookedPinball AC/DC bolts failed with little use.

2 of 3 are dud.

In Flash test mode I put the original stock bolts back in and they work fine.

Did some troubleshooting of the Hooked bolts which are faulty:

• Re terminated the connectors
• Reflowed solder
• Checked the PCB connections

The really strange thing, I can get the Hooked bolts working temporarily by using my fingertips and applying pressure anywhere along the length of the heat shrink cable in flash test mode. It will stop working after a while but when I apply pressure again it works.

Thoughts?, is this body capacitance?

I’m assuming the PCBs are goosed and have replaced the originals back.



Check the vids - you’ll see what I mean.

It did the same on both of the faulty Hooked bolts I:e not flash during test mode - apply pressure then suddenly works for a while then goes off.
It doesn’t matter where I apply pressure, I tried under the playfield, near the connectors on both bolts, same result, doesn’t flash but then flashes after pressure applied.

View attachment IMG_4229.MOV



View attachment IMG_4232.mp4

 

[Pick Holder]

I don’t know the reason that happens.
I would be tempted to get a sharp knife and remove the heatshrink all together and replace the whole cable with a twisted pair.
Then replace heat shrink.

 

[Sako-TRG]

I resigned myself to it be goosed so I did removed the heat shrink with a Stanley yesterday.
I split the PVC from the positive + negative to inspect the inner core through its entire length and it was sound.
Unfortunately, the PCBs used are not great. The metallic round disc area where you solder to only allows a few goes at solder attachment. Now it won’t hold solder any longer as it’s lost its metallic properties, down to the fibre glass epoxy so cannot solder a twisted pair

 

[Vimtoman]

A lot of guys making mods use single core wire for some reason. Not a good idea if the cable has constant movement.
Its probably a hairline crack in the wire due to fatigue and your pressing is making the connection.

Youll need to rewire the mod somehow.

 

[Sako-TRG]

Yeah, the cores are stranded not single core.
Also, it doesn’t matter where you press on the cable on both bolts. It could be bottom, middle or top so there’s no break. I also inspected the inners.

 

[Sako-TRG]

Also when you apply pressure the flasher doesn’t work immediately, it takes around 5-10 seconds.
Which is why I think it’s something to do with capacitance. - above my head

 

[Vimtoman]

The alarm type stranded cable is really cheap crap and breaks by just a few bends.
You can check by pulling the wire with ppliers at one end to see if it pulls through the sleeve.

Whats on the pcb? maybe they have a simple CR delay circuit gone bad

 

[Drew.m]

sounds like a break in the cable, they can be really tricky to find, to put the body capacitance theory to bed (or not) put some gloves on and see if it is the same

 

[Sako-TRG]

It was the PCBs at fault.
Confirmed with Rob at Hooked Pinball..... he’s been a great help and will be shipping 3 x new PCBs
Thanks for input all.