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]

Where does the voltage for the relay come from?

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.

[HHaase]

Leftmost fuse on sys6 power supply is power to the flippers.  Shouldn't keep it from starting a game, would definitely keep the game from being playable though.  Might find the next fuse bad too,  and you may want to look at replacing the backbox rectifier for the solenoids.

Right now though I'm only running on 1 hour sleep since noon yesterday, so I'm just too tired to take a serious look at the problem right now while also chasing the baby.  Will come back with more ideas after I've had some rest and have my skull CPU running at full speed.

-Hans

[lilshawn]

Turned it on the next day, machine lights up but won't start a game.

you'd be surprised what pressing down the main CPU chip will do. also give the mainboard connectors a re-seat.

[SirPeale]

Turned it on the next day, machine lights up but won't start a game.

you'd be surprised what pressing down the main CPU chip will do. also give the mainboard connectors a re-seat.

All that was done already.  Replaced the connectors, reseated all socketed chips...

My guess?  The solenoid fuse is also bad, but "looks" good.  The guy doesn't have a meter to test the fuses, so that's out. 

What's the rating on the flipper fuse?  The guy states it only says "32V" and "ACC15".  ACC is the fuse type, but I don't see that being a 15A fuse.

[lilshawn]

Power Supply Fuses:
F1 = Score display 90 volts AC, .25 amp Slow Blow.
F2 = Solenoids 28 volts DC, 2.5 amp Slow Blow.
F3 = Lamp matrix 18 volts DC, 8 amp Fast Blow.
F4 = Flippers 28 volts DC, 10 amp (2 flippers) or 15 amp (3 or 4 flippers) Fast Blow
F5 = 9.3 volts AC (input for +5 volts), 7 amp Slow Blow.
F6 = 9.3 volts AC (input for +5 volts), 7 amp Slow Blow.
F7 = General Illumination for pinballs, 6.3 volts AC, 20 amp Fast Blow.

Sound Board Fuses:

F1 = 9.3 volts AC, 4 amp Slow Blow.
F2 = 9.3 volts AC, 4 amp Slow Blow.

[HHaase]

This is an earlier machine, with the System 6 power supply in it, so it's got a different fuse layout.
F4 is the flipper fuse, all the way to the left, 15amp slow blow.
F2 is the next one in, for the solenoids, 2.5amp slow blow.

If it's just the flipper fuse blowing, do the regular tests of the coil resistance, check the EOS switches.   Don't forget to check that the rubber insulation is in place on the flipper pawl where it contacts the EOS switch, or you could be grounding out the coil power into the flipper bracket. 

If both of those fuses are blowing, then the first common component in the circuits is the left side backbox rectifier.  Standard stuff there, 35amp 400v rectifier available everywhere, easy enough to test/replace. I assume you already put the additional fuses on one of the AC input legs for both rectifiers?   Also, solder the wires down on the rectifier legs, connections there can get corroded and cause all sorts of issues in the long term.   

-Hans

[lilshawn]

This is an earlier machine, with the System 6 power supply in it, so it's got a different fuse layout.

Power Supply Fuses:
F1 = Score display 90 volts AC, .25 amp Slow Blow.
F2 = Solenoids 28 volts DC, 2.5 amp Slow Blow.
F3 = Lamp matrix 18 volts DC, 8 amp Fast Blow.
F4 = Flippers 28 volts DC, 10 amp Slow Blow
F5 = +5 volts DC logic, 4 amp Fast Blow.

Sound Board Fuses:

F1 = 9.3 volts AC, 4 amp Slow Blow.
F2 = 9.3 volts AC, 4 amp Slow Blow.

Backbox Panel Fuses (located below power supply board on a fuse card):

6F1 Yellow Wires = General Illumination 6.3 volts AC, 20 amp Fast Blow.
6F2 Gray Wires = Logic 9.3 volts AC supply, 4 amp Slow Blow.
6F3 Gray Wires = Logic 9.3 volts AC supply, 4 amp Slow Blow.