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Sys11 Coil locked on, lots of coils not working

Closing the relay contacts simply re-directs each of the power inputs, 25 and 50v, from 'A' output to 'C' output; what happens otherwise depends on the game program operating one of the eight extended solenoids - if it doesn't then nothing else happens, since there isn't a return circuit for anything on the C side (I think they're all flashbulb circuits with this game).

There is a method for the program to see if the relay isn't working - when it operates, a current sensing opto-coupler detects C side power and shows in the switch matrix as switch no. 02. This is what the A/C switch test is looking at.
 
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So the relay must be screwed? I need to test if it's getting power?

I think @AlanJ advised me how to do this via BR1 and it seemed to be OK but will have to double check.
 
Not trying to be an idiot here but if you are breaking off transistors and cutting relays open you may not be in the right line of work.
Anyway, with that out of the way: As Jay wrote, the relay is just an electrically operated switch. It switches 25V coming in on pin 5 between pin 1 (A) and pin 3(C) as well as 50V coming in on pin 6 between pin 2 (A) and pin 4(C). Those voltages then go via F2A (25V) and F2C (50V) to J11 pin 4/5 (A) and pin 1/2 (C) and J12 11/12 and 9/10. With power off, put your meter on continuity, measure between pin 5 and 1 of the relay, you should have continuity. Moving the armature you should have continuity between 5 and 3. If it is 5 and 3 all the time or neither, the armature is stuck, contacts are bent or whatever. Provided you can switch between states manually, you have an issue with the fuse F2A or the associated plug or cabling. This can be the fuse, a cracked solder connection, broken trace or a combination of the above. You need to re-seal the relays to keep dirt and oxidation at bay, would probably best to replace them.
 
drhex said:
Not trying to be an idiot here but if you are breaking off transistors and cutting relays open you may not be in the right line of work.
Anyway, with that out of the way: As Jay wrote, the relay is just an electrically operated switch. It switches 25V coming in on pin 5 between pin 1 (A) and pin 3(C) as well as 50V coming in on pin 6 between pin 2 (A) and pin 4(C). Those voltages then go via F2A (25V) and F2C (50V) to J11 pin 4/5 (A) and pin 1/2 (C) and J12 11/12 and 9/10. With power off, put your meter on continuity, measure between pin 5 and 1 of the relay, you should have continuity. Moving the armature you should have continuity between 5 and 3. If it is 5 and 3 all the time or neither, the armature is stuck, contacts are bent or whatever. Provided you can switch between states manually, you have an issue with the fuse F2A or the associated plug or cabling. This can be the fuse, a cracked solder connection, broken trace or a combination of the above. You need to re-seal the relays to keep dirt and oxidation at bay, would probably best to replace them.
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Well it's not my line of work, it's a hobby where I've been learning as I go and done okay with most issues till now.
Things broke off the board because they must be old, I barely moved a transistor and its legs snapped off so it must have hit the power lead of the iron or something when I was flipping the board over to do the other transistors

I've done the continuity test on the relay already and it tested ok

The fuse is fine as I have measured the voltage on both sides of it when the relay is closed for the C side.

I do have a replacement board but if the issue is more obvious than it seemed when I got frustrated and ordered a replacement I don't mind giving it a go.
Saying that, it looks extremely daunting removing a relay without damaging the board as I can't cut the legs off.
 
If you must remove the relay there’s nothing daunting about it. For me you need a good solder sucker and a 35w (minimum) soldering iron. If you’re using an 18 or 25w one with a fine tip you’ll get nowhere. Reflow a bit of new solder onto each tab before you use the sucker.
 
I think we figured the relay coil is not testing out on continuity anymore, (you did a continuity or a diode test and it failed one way, but worked the other way due to the diode) so it needs replacing.
 
If it were mine, I would try reflowing the pins on the relay just to rule out cracked solder joints on the relay pins. It would take less than a minute and if the relay needs to come out a little extra solder will help with the flow of the solder sucker.
 
From Clay's guide on Data East (equivalent transistor on Sys 11 is Q8 - did you have to replace that one, David?)

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Just measure the coil of the relay, if that‘s open it is shot. You should be able to actuate it with a nine volt block to test it working. Reflowing the joints is a great idea as mentioned above. To my understanding you don’t get A though which I think is relay off - that would suggest the armature hanging or the reset spring being off.
You can send me the board plus relay, happy to switch it out for a beer.
 
drhex said:
Just measure the coil of the relay, if that‘s open it is shot. You should be able to actuate it with a nine volt block to test it working. Reflowing the joints is a great idea as mentioned above. To my understanding you don’t get A though which I think is relay off - that would suggest the armature hanging or the reset spring being off.
You can send me the board plus relay, happy to switch it out for a beer.
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Open meaning? I'm still learning... Can I test via continuity?

A didn't originally work but it does now. It's C that doesn't.
The resting position of the relay is for A as far as I know.
The relay doesn't fire at all.

Might take you up on that offer. But I might attempt it myself as I have a backup board so it's not so bad. I'll just lose more money 😆
 
Correct, it is stuck in its resting position. Measure resistance across the coil, should be low ohms. If open, it is shot. If it has a few ohms it should work, put voltage on it with a batter and see what happens. If it clicks, you have a break in the traces somewhere.
 
David,

You can measure resistance of the coil across the legs of D23 - it should be about 600 ohms (that's what it is on mine).

Resting position is A.
You already said above that you do not have continuity between D23 and F2A. You should have continuity as per your working board.
Do you have continuity between W6 and F2A? (test at the right hand end of F2A where F2A is written on the board. I suspect you do not. If you do not, then test whether you have continuity between W6 and F2C. If you have continuity, the relay is locked on and will no doubt need replacing (and probably Q8 also shorted on). If you also don't have continuity between W6 and F2C then either the relay is broken, or you have cold colder joints at W6, Pin 5 or 6 of the relay, or the right side fuse clip of F2A. Reflow the joints, see if it works and if if doesn't the relay is toast.

Hope this helps and doesn't confuse further. Dr Hex and I are saying the same thing, just in different ways.

Paul
 
Small addition to what Paul said: measuring resistance across the coil with a diode in parallel requires you to get the polarity right, ie with the diode blocking, so plus of your multimeter on the banded side of the diode. Would suggest that you measure on the pi s of the relay first to make sure you don’t have a cold joint.
 
At the risk of confusing the thread, 'open' (the concise* form of 'open circuit') means without a conducting pathway, i.e. an open-circuit coil has broken somewhere in the winding, or an open-circuit transistor isn't going to conduct any more, in any circumstance. Such a condition only shows in a continuity test by the absence of a reading, or sound, as there's no connection.

I'm sorry to have been so curt yesterday, but it was chucking-out time at the public library. I'd missed the disclosure of the relay failing.

This may sound fanciful, but if you'll pardon a railway analogy; current leaves the 'depot', the +ve terminal of the bridge rectifier. Fuses 1, '2' and 3 are similar to main lines. Track '2' negotiates some points at the relay, which allows it to reach either the 3 solenoids on 'A', or the flashbulbs on 'C'. From the other side of each coil (or group of bulbs) is then its own branch. Each pair of branches, e.g. 1A and 1C, re-join on the aux power board using a pair of those large diodes. After this each branch/circuit has its own drive transistor, a signal as it were, which when On (or green) allows current to complete its journey to ground. The depot also runs some service or 'engineering' lines, in particular to control the relay/points; a line solely to pass through the relay winding and its transistor. For 25v circuits, the transistor is the one listed in the chart, on the Cpu/driver board, while for 50v circuits it's an additional transistor on the Aux Power board, though this transistor is in turn controlled from the Cpu board.

With this relay, I see now how D 23 (and D 12 for that matter) came into the discussion. It's connected in parallel across the relay winding, as diodes used to be connected across coils. If, as we suspect, the winding is open-circuit, checking for continuity would have the same results as simply checking a diode, i.e. a continuity in one direction, but not the other.


* careful choice of alternative to 'short', in this situation
 
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I'll read the reply and try understand it shortly, when I'm awake (all nighter with DINER😁).

But I have to ask, are you using the railway analogy because I'm a train driver or is it a coincidence?😂
 
Jay Walker said:
It is due to that, but it makes a change from the usual 'flowing water' analogy.
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Appreciate it!

I'm not in a hurry to attempt fixing the board as I got the replacement and I've got locomotion being a silly pin now.
I'm happy to try understand more about it so it'll be worth having a go, although someone has offered to swap the relay out 😁
 
Jay Walker said:
With this relay, I see now how D 23 (and D 12 for that matter) came into the discussion. It's connected in parallel across the relay winding, as diodes used to be connected across coils. If, as we suspect, the winding is open-circuit, checking for continuity would have the same results as simply checking a diode, i.e. a continuity in one direction, but not the other.
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Very important point this as written above - take care to put the leads on the right way to measure the relay coil, plus to banded side. Again, measure on the relay pins first! And yes, happy to swap the relay out for you (if broken).
 
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