Weak solenoid issue

[DRD]

On my vector I have a solenoid problem. When you turn it on and begin playing, all is well.

But shortly afterwards, this solenoid fails to pull the sprung loaded armature strongly enough so there is an annoying vibration caused by inadequate solenoid force.

The solenoid is on the coin door. It pulls an arm that stops you from putting coins in the three slots when the game is turned off

I have pictured it below. It is receiving 43 volts according to my multimeter. There is very little weight on this armature. I have lubricated the contact points with Teflon spray, but that achieved nothing

Does anyone have any ideas please ?. I know the easy option is to disconnect this solenoid as I do not need a working triple coin slot. I am loathed to simply buy a new solenoid, but that would be my next move. This thing seems to be energised the whole time the game is turned on and does get a little warm. It may be that the solenoid is simply shot or cooked.

 

[Carl Spiby]

What resistance do you get between the coil lugs?

 

[DRD]

Hi. I disconnected one of the power wires to it. But the diode is wrapped around the terminals and soldered both sides. Will be a bit of a job to remove one end and I risk snapping it

I measured the resistance at 535 ohms with the diode in place, and it tried this again swapping the - and + terminals and the result was the same

Do I need to remove one end of the diode too ?

Thanks

 

[Carl Spiby]

535ohms seems rather high.

 

[DRD]

Thanks Carl.

Given that this thing is energised the whole time the game is running, I just wonder if it got cooked over time. At least I almost hope it did. Or worse, it could be indicative of a power supply issue. I have learnt over the years that electrical circuits can be quite happy when cool, but after they have warmed up, the increased resistance can yield all sorts of problems

I am also fast learning that pinball machines bought from uncaring/ unknowing owners on eBay are a bottomless pit. My replacement parts list for this game is racking up fast. And some require overseas suppliers

 

[Carl Spiby]

If you still have full voltage there when it's struggling then it's got to be the coil, in the meantime, you could just pop the spring off so it doesn't need to do any work.

 

[DRD]

Thanks, a good simple solution !

I will add a new coil to my next purchase. So far on this game I am at 3 coils and counting ....

Do not trust eBay.

 

[Jay Walker]

On electronic machines, the coin lockout is energised once the mpu board has booted up, and only cuts out once maximum credit is reached, and briefly (on Bally games) while the playfield solenoids reset targets, etc, for a new ball in play. If you'd like to disable it, take off the return wire, from the terminal with the plain end of the diode.

I found with Stern games that used a similar arrangment that it only needed a slight mis-alignment of the actual moving bar, or the brackets for the coin mechanisms, to cause the symptom you've described. In fact, Stern stopped using the lockout before anyone else.

 

[Biff]

clean and lubricate all metal to metal contact points on the load side - do not apply to the solenoid. Check the face of the solenoid and the metal (keeper plate) it connects with. make sure they are flat with full surface area connection between the two, when energised. A new coil may not solve the issue if the face of the metal that connects to the core is divited or worn. The pic you sent, is this in the energised state, or de-energised? If energised, the keeper plate has been deformed, the face of the magnet and the metal it connects with must be lined up when energised. Als check spring tension. should be just enough to take the keep plate away from the magnet when it denegergses.

In the EM world, you get some weeknes and hum or buzz in relays that are used a lot, like index and lock. Coils look cooked, with scorched or missing paper, but the coils are fine. It is always IMHO, fileing the plate and cleaning up the surface contact between the two that stops the hum.

JB

 

[DRD]

Thanks for all suggestions. There is wear in the mechanism. I actually think that there was a dry joint on the coil too as it now seems to have a bit more power.

I will work on getting the hinge as good as it can be and getting the surface contacts nice and square.

 

[carl lawrence]

When I had my vector, some one had cut the tip 102 off the board ,I think to make the coin door save ,ie no high power to the coin door! The game worked fine but I did have the free play Roms in !!

 

[DRD]

I think I have solved it. Two problems.

1 I think there was a poor solder joint on the coil, resoldering helped

2 these hinges are so crude, it causes problems. Twilight zone has one too, on the shooter diverter. There was wear in vector. As the tension spring was not directly behind the plate, it was introducing a twisting motion as it pulled vertically upward. When the mech was new, it probably did not matter, but with 30 years of wear, a different story.

I got rid of this by drilling a new hole. Seems to have done the trick. You can see the original holes and the new one below