Arcade Collecting > Pinball
Black Knight pin blowing fuses
SirPeale:
I'm trying to wrap this up. Before I embark on a two-hour one-way drive (and back, of course) I want to make sure my bases are covered here.
I've replaced the 40 pin connector on the driver board. I've cleaned up the battery damage. And I've replaced the relay.
I've got replacement transistors to swap out on-location (because I stoopidly did not mark down which solenoids were reading as bad on location).
My concern is this: the flippers were working, but the special solenoids were not. That means (I assume) that they're not getting power.
I've been going over the schematic so I can include any possible parts along with me for my trip. What should I bring so I can check stuff off?
This is the last long-distance repair like this I do without bringing back the machine; I would have had it done by now if I could take those measurements as I'm doing things.
HHaase:
Just a few extra thoughts........
There are a lot of scattered solenoids that you might overlook at first, which are unique to older machines.
Double check the solenoids for the coin door lockout, it's right next to the lock tumblers on the inside of the coin door, and got the bell on the inside of the cabinet, left sidewall about half way back. Most people don't even realize they are there and never check them.
The good thing is that it looks like you're dealing with a system-6 power supply, which avoids all the GI issues of a system 7.
For the solenoid transistors, use TIP102's instead of the TIP120's, they're more robust.
Then you have the 7408 IC chips, I assume you put these on sockets already? Don't use 74LS08's, apparently they don't deal with the load well, but you can use 74F08's.
Definitely bring up some 9pin .156 molex connectors, at least 4 preferably six, and swap the connectors for the solenoids, specials, and possibly the lamps as well. Use trifurcon pins if you have them. The IDC connectors cause all sorts of havoc long term, what a pain in the ass they can be. Inspect the board for these connectors as well, look for cracked solder joints, if you already have the driver board you might want to consider swapping the headers while you still can.
Now that I've had my own Black Knight for a few weeks, and have really started diving into how the board works, I'm getting a good handle on what can cause what. It's simpler than it looks, just a lot of the same stuff repeated a number of times, both on the board and the playfield.
I'm surprise nobody threw this link out yet
http://www.pinrepair.com/
It REALLY covers the system 7's fantastically.
-Hans
SirPeale:
I already figured out which two solenoids were "causing a problem" and disconnected them. I don't think it's the solenoids themselves, but their associated drivers. Thank you, battery damage.
Where does the voltage for the relay come from?
HHaase:
--- Quote from: SirPeale on May 06, 2010, 07:04:30 am ---
Where does the voltage for the relay come from?
--- End quote ---
Tracing backward from the relay on the driver board it goes through......
Q13 (2n4401), then IC8 (7402), IC9(7402) and IC7(7408).
IC8 also handles special solenoid's 2, 3, and 4's drive.
IC9 gets it's hands into essentially all the special solenoids one way or another.
-Hans
SirPeale:
Revisting this finally.
Was there on Tuesday. Figured out which drivers were bad, replaced them, popped the boards in the machine...presto...working machine.
Well...working-ish. Lots of switches out of sorts and needed adjusting. But when I left it was fully working.
Told the guy to play it play it play it PLAY IT. He played it all that day, and the next.
Turned it on the next day, machine lights up but won't start a game.
He's stating that in the photo above, the leftmost fuse is blown - what fuse is that? I don't have Acrobat on this machine, otherwise I would have looked at the schematic Chad posted above.
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