Stand up target not working, could it be the diode?

[David_Vi]

Another beginner question.
I've managed to solve a few issues with my pins so far but today Black Rose complained about one of the targets.

I've done a switch edge test and checked the wiring.
What more could it be other than the diode? If diodes can just die?

How can I test it? (i don't yet have a multimeter, i know I need one!)
And what is the type of diode for that situation?
Annoyingly as always I've already placed an order for some parts an hour before I knew the leaf switch was dead

 

[M4carp]

You could also try reconnecting the connectors on the bottom of the cpu board, they are for the switches.
Sometimes this will fix a switch issue, plug it in and out a couple of times to clean the pins a bit.

 

[David_Vi]

Yet again I've jumped the gun... As simple as cleaning the contact!

I'm so sorry every days a school day with pinball!

 

[Garry Sp8]

Or could be a wire off another switch in the chain. Switches are daisy chained together in rows and columns. A wire off one switch could affect one or more in the same chain.

 

[Pick Holder]

You can use a 1n4004 or 1n4007 on a target. It is usually a wire off. Follow the wires on the target thru the loom, and check the other switches on the rom/column to see if anything else is out.
Also do you have any switches that trigger other ones at the same time (this can be a problem with a diode and wiring).

 

[Andydn]

Always try the most non invasive, simple fixes first [emoji106] well done on sorting it mate.


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[David_Vi]

Even though it was the most simple solution, do diodes fail without intervention?

I'm thinking i should order a few ready for the inevitable, even if a few months down the line.

 

[AlanJ]

yes they do fail every now and then so worth having a few in your spares box. 1n4004 are cheap as chips, ebay


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[DanLewell]

I might be wrong, so someone will probably tell us otherwise in a minute, but,

If a diode fails you will usually get a different switch activating instead of the one you are trying to trigger. So in test mode if you press one switch and a different one activates then you've probably got a diode issue. Not necessarily on the switch you are pressing though.

If you short the two wires under the playfield and it registers correctly then it will be the switch itself that needs locking at. Contacts / Faulty switch.

 

[David_Vi]

I might be wrong, so someone will probably tell us otherwise in a minute, but,

If a diode fails you will usually get a different switch activating instead of the one you are trying to trigger. So in test mode if you press one switch and a different one activates then you've probably got a diode issue. Not necessarily on the switch you are pressing though.

If you short the two wires under the playfield and it registers correctly then it will be the switch itself that needs locking at. Contacts / Faulty switch.

That makes sense, i think i understand that (put really simply) diodes are like one way gates. So if one failed the power to the associated lamp or switch would go back and end up lighting or activating others?

 

[AlanJ]

That makes sense, i think i understand that (put really simply) diodes are like one way gates. So if one failed the power to the associated lamp or switch would go back and end up lighting or activating others?

yes and yes


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