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Flash Gordon light fault (and now whole game not working!)

VeeMonroe

VeeMonroe

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Having changed from incandescent inserts to LEDs, we've noticed a bunch of insert lights out on Flash Gordon.

We've started by testing the 8 mini-bonus light. We've checked the fitting and bulb resistance, and the resistance between the ground cable and the solder joint at the other end of the fitting is 470 ohms for both the good and the bad lights. We then checked continuity between the output on the lamp driver board and the fitting, and there appears to be a good connection. We think the problem may be with the driving thyristor on the lamp driver board, largely because thyristors have a reputation for being more temperamental than the other components in the circuit.

Does anyone have any better ideas before we order a bunch of thyristors (not to mention taking on a nightmare soldering job)? @AlanJ your thoughts would be especially welcome as I know you're familiar with FG :)
 
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And now, joy of joys, the entire pin isn't working. We lifted the playfield and the inserts and displays no longer go on, and it won't start up a game. The GI is on and the sound board is working.

We've checked the fuse on the solenoid driver board (the only visible fuse) and that's fine. The CPU board power light is on.

Both lamp boards have power, testing at the test points, as does the solenoid board.

The CPU board on switch on gives two flashes and then five flashes. The manual says it should be one, and then six, but we have an Alltek CPU board, and unsure if behaving differently.

We had not touched the CPU board at the point where everything went off.
 
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You should get 6 flashes after the pause.
Video of Alltek booting in fg attached.

Lack of last flash means fuse for 43v is blown on the power board or otherwise not reaching the cpu
 

Attachments

When it is running again, the lamp driver board has a resistor-protected test point which can be used to safely switch the gate of any thyristor in order to check the device and the lamp(s) or l.e.d.'s connected.

As you most likely realise, it seems that the mpu board isn't booting up, hence no displays or Attract Mode lamp activity, or operation of the coin lockout on the door. The number of flashes can be misleading, though; some games are slow to start the self-test, and the s/test l.e.d. can light up quite well of its own accord before the program gets around to supressing it and beginning the test. If that's the case here, and you're really seeing six flashes, that means the Zero Crossing test has failed, often from absent solenoid voltage (it's taken to the Mpu board simply to power the Z/C detector). As Andy points out.
 
Can you be more specific about the ‘bunch’ of non working insert lamps?
 
Non booting : sounds like you are missing last flash. check the fuses in the bottom of the cab on the rectifier board.

once you get it booting ok, then for the feature lights: check all connectors to the lamp driver board are on properly. try putting an incandescent back in, does it work. make a list of all non working lamps
 
pinballmania said:
You should get 6 flashes after the pause.
Video of Alltek booting in fg attached.

Lack of last flash means fuse for 43v is blown on the power board or otherwise not reaching the cpu
Click to expand...
Thanks @Jay Walker and @pinballmania. We haven't done any board work on FG since we got it so, embarrassingly, hadn't grokked it had a whole other set of fuses in the cab. I thought it was a bit weird that there was only one visible fuse - electrical safety was a thing in 1981!

pinballmania said:
Can you be more specific about the ‘bunch’ of non working insert lamps?
Click to expand...

They're not running off the same connectors, or even the same board, and some are intermittently coming on - so, I'm suspecting a range of faults...

We're missing:

1 on upper drop targets
Lower two rollovers in shooter lane
10,000 light below saucer (intermittently working)
20,000 light below saucer
5 mini bonus (intermittent)
8 mini bonus
Left inlane special
Clock 15 seconds x 2 (both of them out)
Shoot Again @ outhole works on lamp test, but not when I get an extra ball (we think it might be in tournament mode because I've never received the extra ball despite getting/hitting it loads of times).

When the fuse blew, we were going around testing the resistances and connectivity on all the non-working lights to see whether it was the bulb holder, the wiring or the same problem as the 8 mini bonus.

AlanJ said:
try putting an incandescent back in, does it work. make a list of all non working lamps
Click to expand...

Thanks :) We'll try an incandescent, as well. I've got to admit I didn't realise how many of the lamps were out until we swapped to LEDs because the pin is in a brightly-lit room.
 
hmm. is it a new alltek lamp driver board or an original one?

if an alltek, then you need to connect an extra wire to support leds

if an original you need anti flicker adaptors OR resistors soldering across each lamp socket for leds to work properly

as i mention above, try putting an incandescent back into a couple of the non working ones
 
AlanJ said:
hmm. is it a new alltek lamp driver board or an original one?

if an alltek, then you need to connect an extra wire to support leds

if an original you need anti flicker adaptors OR resistors soldering across each lamp socket for leds to work properly

as i mention above, try putting an incandescent back into a couple of the non working ones
Click to expand...
It's an original lamp driver board, but we got a Comet LED kit with flicker adaptor boards. We've checked the connections between the adaptor and main boards as best as possible, and it doesn't seem to be that.

My guess is that, unfortunately, the incandescent lamps were out when we got the pin. It also arrived with a (known) fault on the saucer caused by the wrong solenoid coil and the flipper bats needed replacing. I guess my mistake was to assume that the top of the playfield and cab was so beautifully done up that it had work done throughout, but I've subsequently learned that you don't need to strip the underside of the playfield to fit a hardtop, so I guess none of the under-playfield work was done when the pin had a going over.
 
Ok that’s all good. If those lamps in question have never worked, then it’s probably the lamp driver board at fault. but if some are intermittent that is more likely a loose connection - either connectors or perhaps the lamp socket itself.

ps i’ve got spare lamp driver boards fully tested and working.
 
If this is any help, each insert or 'feature' lamp has the 5.4v rail connected, with the return wire routed to a lamp driver board (Bally's standard 60-circuit board and one of a few different additional boards). For each circuit, the thyristor/Scr switches on if the lamp is required, refreshing after every zero crossing. Which loads are deemed as required depends on the data and address lines controlling the board(s); for the main board, anyway, there are four decoder chips, each providing 15 outputs. The program grinds through each step from a binary 0000 to 1110, addressing each decoder simultaneously using 'lamp address lines'. Which of four possible outputs switches On for each pass depends on which of the decoders are enabled, using 'lamp data' lines to select or overlook the decoder chips.

The manual will be a help with this, comparing which lamps aren't working with the schematic pages for the two lamp boards. It's TP 3 on the main lamp board that can be used to by-pass the decoding side and switch an Scr directly. The additional board doesn't seem to have one, though a lead from the main board TP 3 would suffice. Alan has developed a test module that may be handier.
 
AlanJ said:
^ good point. are the duff lights on the main lamp driver board or the auxiliary lamp board?
Click to expand...
Both...

We've now got the pin working again, thanks to you both :) It seems that with at least a couple of the lights the problem is actually that the socket is loose, and we were putting enough pressure onto the socket with the multimeter to create a connection when the pin was off. With the pin on, a couple of the lights came on when we prodded the socket with the multimeter probe!

AlanJ said:
ps i’ve got spare lamp driver boards fully tested and working.
Click to expand...
Huge thanks for the offer. That may turn out to be the best option with some of the lights. We're due to be at Pinfest, IVF cycle permitting, on Saturday, so might be interested in buying one off you if that's the problem with some lights and it isn't a huge faff. I'll let you know, if that's okay, as we're still testing :)
 
Yep no probs. I also have New old stock insert lamp holders. or even better replace the whole socket and led bulb with my ledBars - loads of options !!! 😃
 
It was Stern games that had really poor lamp sockets; even at a few years old, many lamps were intermittent. Bally sockets seemed better, but it has been 40 years now.
 
Now all working except for one missing and one loose solder joint, and a bunch of loose connections around the insert lights. Bonus 9 also seems to be permanently on now, for some reasons.

Huge thanks for all the help with this 🥰 Really appreciate it :)
 
And the lamp driver board uses scr not transistors and can be problematic with leds. If in doubt run 555 incandescent and if still jot working replace the scr.
 
Going by the schematics, 9,000 Mini bonus is switched by Q13, and 9,000 Super bonus by Q10 (both on the main Lda board). A damaged Scr or the return finding an earth somehow may be the problem.

I've learnt something from peeking at the manual on-line; it's possible (though I suspect very rare) to achieve a timed 5X playfield multiplier. I've had a manual at home for years, but it's in German.
 
Jay Walker said:
Going by the schematics, 9,000 Mini bonus is switched by Q13, and 9,000 Super bonus by Q10 (both on the main Lda board). A damaged Scr or the return finding an earth somehow may be the problem.

I've learnt something from peeking at the manual on-line; it's possible (though I suspect very rare) to achieve a timed 5X playfield multiplier. I've had a manual at home for years, but it's in German.
Click to expand...
So… we’re back on solving the problem with the 9k mini-bonus, which is permanently switched on.

We waggled the bulb and something blew (I heard a pop and the bulb is now off). We’ve obviously switched bulbs around, checked voltages, etc. and both ends of the bulb are now at +7V of the common return line.

I can’t see any smoke of death on the lamp board on Q13 or on the pin (J17 IIRC).

Our best theory is there was something creating ground for the lamp and, when we waggled it, it created a short circuit that blew something.

Just wondered if anyone had any ideas, as we have no idea?
 
If the lamp was stuck on then you need to replace the scr and check that the socket is in good condition. If the parts are separated then the supply can short to the drive. Initially this may cause the scr to short circuit, and if the short is prolonged the scr will pop and go open circuit.
 
Sorry to resurrect this thread, but it makes more sense to continue here I think.
I have been the owner of this pin for 24hours, today I have installed @AlanJ lamp driver board and have replaced a couple of the lamp holders which appeared to be the problematic ones for @VeeMonroe

I am left with two insert locations where I've tried; reflowing, multiple holders and various bulbs but they will not work;

-'Clock 15 Seconds' Left side of the playfield
-'Shoot again'

Checking with the multimeter I'm convinced are fine just these f#ing awful style holders are all untrustworthy.

-Also worryingly the two top left inserts '1,000 Advance' are lit continuously like they are part of the GI ? Surely that's a fault and not by design?


Apologies if any of this has been covered above previously, I'm not yet used to tinkering with Bally's.
 
Hi @Crewey ,
I am assuming that you have new
Lamp holders in “shoot again “ and “15 seconds “. Also assuming lamp driver board is good. Sounds to me you will need to re-pin the following connectors:
1) shoot again. A5 J2 pin 21. (Green/orange)
2) 15 seconds. A9 J2 pin 17. (2x green/yellow) (3x A9 J2 pin 9 white / green)
Where A5 is lamp driver and A9 is aux lamp driver.
The two star rollover’s top left are correct. Always lit. Keef……👊🏼
 
Crewey said:
Sorry to resurrect this thread, but it makes more sense to continue here I think.
I have been the owner of this pin for 24hours, today I have installed @AlanJ lamp driver board and have replaced a couple of the lamp holders which appeared to be the problematic ones for @VeeMonroe

I am left with two insert locations where I've tried; reflowing, multiple holders and various bulbs but they will not work;

-'Clock 15 Seconds' Left side of the playfield
-'Shoot again'

Checking with the multimeter I'm convinced are fine just these f#ing awful style holders are all untrustworthy.

-Also worryingly the two top left inserts '1,000 Advance' are lit continuously like they are part of the GI ? Surely that's a fault and not by design?


Apologies if any of this has been covered above previously, I'm not yet used to tinkering with Bally's.
Click to expand...
Just to check you've found our shop log? All the debugging we did is in there and that might help.
 
To be honest @AlanJ there were a lot of bulbs not working when I switched on for the first time last night, so just switched the boards without lifting the playfield this morning.
Once the other board was in place I started working through the unlit ones, switching bulb holders around, reflowing etc
I was left with those two mentioned, I’ll check again tomorrow as I’m not convinced it’s still not just the holders being next to useless by design.
I’ll repin the connections Keef mentioned and if still the same I’ll switch boards back again to see if anything varies :thumbs:
 
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