Interlock switch

[felixthadog]

I have removed the Interlock switch from my TZ machine but when I go into the Solenoid Test menu, the coils fire as though the Interlock switch is still connected. Please correct me if I am wrong, but my understanding is that the Interlock switch cuts power to the coils when the coin door is open to prevent accidental short circuits or zaps. If the Interlock switch is removed, shouldn't power to the coils be cut permanently? 

Matthew

[ajlaird]

Not really, on the Dirty Harry you can still do all the solenoid tests with the coin door open. This is after the interlock message comes up on the DMD on opening the coin door.

[felixthadog]

Not really, on the Dirty Harry you can still do all the solenoid tests with the coin door open. This is after the interlock message comes up on the DMD on opening the coin door.

So what is the purpose of the Interlock switch then? 

Matthew

[ajlaird]

Not really, on the Dirty Harry you can still do all the solenoid tests with the coin door open. This is after the interlock message comes up on the DMD on opening the coin door.

So what is the purpose of the Interlock switch then? 

Matthew

I never read the interlock message closely but it is possible mine is disabled and that's what the message says. In which case it is irrelevant, but yeah, the interlock switch is meant to disable the machine until pressed in. Too cold to go and check now - I can check tomorrow.

[silverball]

Make sure the interlock switch isnt sticking......I have seen many that dont release properly as they are kept in the "closed state" most of the time.

[felixthadog]

Make sure the interlock switch isnt sticking......I have seen many that dont release properly as they are kept in the "closed state" most of the time.

Hi Dave,

I have disconnected the Interlock switch completely (the 2 wires are currently not connected to anything) so I would have expected all power to the coils to be cut, but there is still power 

Matthew

[felixthadog]

According to this web-site -> http://www.flippers.be/basics/101-interlock_switch.html, the Interlock switch was introduced "somewhere during the production run of the Twilight Zone pinball machine". Is it possible that my machine is an early production model without an Interlock circuit?  I have never seen the message "Coin door is open Coils and Flashers are disabled" on the DMD when the coin door is open, and according to that same web-site, "You can also see it's installed, the difference is that now there are 2 switches left inside the cabinet that the coin door closes. Older games only had one switch.". My machine only has 1 switch 

Matthew

[ajlaird]

Looks like a real possibility, doesn't it?

Are there any other indicators of an earlier machine you could check for?

[Strangeways]

According to this web-site -> http://www.flippers.be/basics/101-interlock_switch.html, the Interlock switch was introduced "somewhere during the production run of the Twilight Zone pinball machine". Is it possible that my machine is an early production model without an Interlock circuit?  I have never seen the message "Coin door is open Coils and Flashers are disabled" on the DMD when the coin door is open, and according to that same web-site, "You can also see it's installed, the difference is that now there are 2 switches left inside the cabinet that the coin door closes. Older games only had one switch.". My machine only has 1 switch 

Matthew

That's what threw me the when you first asked about the solenoids not working. TZ should have two - but you have one. I'd say that you are correct - If you do not see the message and do not have the switch, then your machine does not have the interlock capability !

So if you put your machine on eBay - You CAN mention it is the "RARE" TZ 

[felixthadog]

According to this web-site -> http://www.flippers.be/basics/101-interlock_switch.html, the Interlock switch was introduced "somewhere during the production run of the Twilight Zone pinball machine". Is it possible that my machine is an early production model without an Interlock circuit?  I have never seen the message "Coin door is open Coils and Flashers are disabled" on the DMD when the coin door is open, and according to that same web-site, "You can also see it's installed, the difference is that now there are 2 switches left inside the cabinet that the coin door closes. Older games only had one switch.". My machine only has 1 switch 

Matthew

That's what threw me the when you first asked about the solenoids not working. TZ should have two - but you have one. I'd say that you are correct - If you do not see the message and do not have the switch, then your machine does not have the interlock capability !

So if you put your machine on eBay - You CAN mention it is the "RARE" TZ 

What is the purpose of the switch I have in my machine then?  I have disconnected it and I can't see any difference!

Matthew

[felixthadog]

Looks like a real possibility, doesn't it?

Are there any other indicators of an earlier machine you could check for?

The clock has the prototype decal and there is an extra hole for a post marked (but not drilled) below the pop bumpers. I think both of these were only included in early production model machines.

Matthew

[Strangeways]

According to this web-site -> http://www.flippers.be/basics/101-interlock_switch.html, the Interlock switch was introduced "somewhere during the production run of the Twilight Zone pinball machine". Is it possible that my machine is an early production model without an Interlock circuit?  I have never seen the message "Coin door is open Coils and Flashers are disabled" on the DMD when the coin door is open, and according to that same web-site, "You can also see it's installed, the difference is that now there are 2 switches left inside the cabinet that the coin door closes. Older games only had one switch.". My machine only has 1 switch 

Matthew

That's what threw me the when you first asked about the solenoids not working. TZ should have two - but you have one. I'd say that you are correct - If you do not see the message and do not have the switch, then your machine does not have the interlock capability !

So if you put your machine on eBay - You CAN mention it is the "RARE" TZ 

What is the purpose of the switch I have in my machine then?  I have disconnected it and I can't see any difference!

Matthew

The door switch simply enables the coin door switches. Thats all it does !

[felixthadog]

According to this web-site -> http://www.flippers.be/basics/101-interlock_switch.html, the Interlock switch was introduced "somewhere during the production run of the Twilight Zone pinball machine". Is it possible that my machine is an early production model without an Interlock circuit?  I have never seen the message "Coin door is open Coils and Flashers are disabled" on the DMD when the coin door is open, and according to that same web-site, "You can also see it's installed, the difference is that now there are 2 switches left inside the cabinet that the coin door closes. Older games only had one switch.". My machine only has 1 switch 

Matthew

That's what threw me the when you first asked about the solenoids not working. TZ should have two - but you have one. I'd say that you are correct - If you do not see the message and do not have the switch, then your machine does not have the interlock capability !

So if you put your machine on eBay - You CAN mention it is the "RARE" TZ 

What is the purpose of the switch I have in my machine then?  I have disconnected it and I can't see any difference!

Matthew

The door switch simply enables the coin door switches. Thats all it does !

LOL, no wonder I didn't see any difference!  I think I will just connect it up again for the sake of looks, but I will have to be even more careful about poking around inside the machine now because there is no Interlock.

Matthew

[silverball]

According to this web-site -> http://www.flippers.be/basics/101-interlock_switch.html, the Interlock switch was introduced "somewhere during the production run of the Twilight Zone pinball machine". Is it possible that my machine is an early production model without an Interlock circuit?  I have never seen the message "Coin door is open Coils and Flashers are disabled" on the DMD when the coin door is open, and according to that same web-site, "You can also see it's installed, the difference is that now there are 2 switches left inside the cabinet that the coin door closes. Older games only had one switch.". My machine only has 1 switch 

Matthew

That's what threw me the when you first asked about the solenoids not working. TZ should have two - but you have one. I'd say that you are correct - If you do not see the message and do not have the switch, then your machine does not have the interlock capability !

So if you put your machine on eBay - You CAN mention it is the "RARE" TZ 

What is the purpose of the switch I have in my machine then?  I have disconnected it and I can't see any difference!

Matthew

The door switch simply enables the coin door switches. Thats all it does !

I believe that this is correct.

Your TZ was definately an early production. I was thinking that it may have been prototype at one stage as it had the original clock decal and factory playfield holes for the extra posts in the pop bumper area.
Apart from the missing interlock switch which appears factory, I recommend you still turn off from the mains when you have the playfield up as there are many other things that can be shorted.

[ktm450]

I haven't seen any TZs with an interlock switch fitted.  Must have been very late in production.