Shadow pinball blowing 8A line filter fuse

[Steelcurtainlou]

Hey Guys-
Turned on Shadow today and it booted up fine. Went to change the time settings, and as I was pressing the menu button to exit out of utility screen, the game completely shut off. I heard the solenoids firing as they usually do before it shut down. I changed the 8A 250V line fuse which was blown, and it started back up and seemed good. I shut the coin door, and it blew again. There doesn’t appear to be any loose wires or anything touching metal. It seems that when the coin door shuts, it causes the fuse to blow. Never had this issue before. Any help is greatly appreciated!!
Thanks-Lou

[BigMatt]

Unplug j102 from the big board and try again, if the fuse pops again when you shut the door its on the cabinet side of things and should be easy to find.

[Steelcurtainlou]

Moved group of wires wrapped together on coin door. Put a new fuse in, shut the coin door, and it seems ok now. I lost all my setting though and it did a factory reset. Very weird? Maybe it’s the wiring in the coin door has a short?

[BigMatt]

Moved group of wires wrapped together on coin door. Put a new fuse in, shut the coin door, and it seems ok now. I lost all my setting though and it did a factory reset. Very weird? Maybe it’s the wiring in the coin door has a short?

Yeah, it would be worth checking the last thing you did before it fixed itself perhaps one of those wires is shaved in the right spot and grounding out, perhaps from the interlock switch itself

[RAW POWER]

There's 110vac running in the coin door area. Shorting that out will definitely blow the line fuse. It's for the bill acceptor connector. It's a square shaped nine pin and the wires are at pins 4 and 6 I believe. Just yesterday I was messing with one of my games and a pin had completely come out of that connector which exposed it to everything.  Lucky I caught it! Hope you find the issue!

[Steelcurtainlou]

Yeah I tucked that wire you said Kurt. I think the initial problem was the coin door was crimping that group of wires. It somehow moved and got in the way. Well good news is that it’s not blowing that line fuse anymore. Bad news is that some of my solenoids seem a little weaker. I know this shouldn’t be a fuse issue because they wouldn’t fire at all, correct? The ball release barely gets ball to shooter lane. It takes a few times. Ball launch is weak and it doesn’t go all the way onto playfield. The vertical up kicker doesn’t have enough strength to get ball to mini playfield. I am showing no test errors and in solenoid test, they all fire- just not with as much power. I looked for broken wires and nothing obvious. I am stumped!!

[dschulpius]

It sounds like you are only getting half power to the solenoid circuit. Test the DC voltage at the coils and see what it is. Also check and test all your fuses.

An AC voltage short to the DC voltage solenoid circuit may have damaged a bridge rectifier on the power section of the Driver board or even damaged the leg out of the games transformer that feeds this circuit.

I'm just spitballing here. I haven't looked at the schematics of this game and can't remember how the solenoids get their DC power or what the voltages should be.

If you find the voltage is low then test at the fuse (is it blown? Probably not if your coils are firing but check anyway). If I remember correctly voltage at that fuse should be AC voltage from the transformer. Can't remember the proper voltage off the top of my head. If that voltage is correct then one of your Bridge Rectifiers are probably damaged. There is a low power BR and a High power BR.

Cabinet and board Schematics and the solenoid/ Flasher table are your friends here. Study them, ID your parts and voltages and test, test, test.

Good luck and let us know what you find. 

[Steelcurtainlou]

Thanks for your response. Unfortunately my electrical testing skills aren’t very good. I have tried everything I know how to do. I’m going to have to get someone out to fix it.

[dschulpius]

Getting a good repair guy is probably a good idea then. Good luck. Please let us know how it turns out.

Just for the record thanks to AI (LOL):

**************
A bridge rectifier uses four diodes to convert alternating current (AC) to direct current (DC). These diodes are arranged in a way that allows current to flow in only one direction through the output.

A bridge rectifier can be damaged and still supply power, but the output will likely be affected. Specifically, if one diode fails open, the output will become a half-wave rectifier, meaning it will only rectify one half of the AC waveform. This will result in a lower DC voltage and a higher ripple. If multiple diodes fail, the rectifier may not function at all.
**************

From what you are describing, the first place I'd look at is the BR's that supplies power to the coils you see that are weak. They are on the driver board. Also, I'd suggest looking closely at that wiring bundle that got pinched (with the power off). If there are any bare spots or exposed wires this could happen again after you get the problem fixed.

[Steelcurtainlou]

Yes I’m thinking it’s something on the power board. I checked that wiring bundle so closely and didn’t see anything which is weird. I thought for sure there was a bad wire there. Hopefully I will get it fixed soon. Thanks for your help!

[BigMatt]

Put a meter on the test points on the driver board for the 50vdc or a flipper coil and look for dc volts, Despite what the schematics say you should be around 70vdc. If you have around 35 one side of the bridge is open(not shorted) which would explain all the coils being weak.

If its marginally lower check for AC ripple(using AC volts) on the same test points if its swinging wildly suspect your big cap for the solenoids