(Topic ID: 194323)

GI problem


By sscnz

2 years ago



Topic Stats

  • 13 posts
  • 5 Pinsiders participating
  • Latest reply 2 years ago by sscnz
  • Topic is favorited by 1 Pinsider

You

Linked Games

You're currently viewing posts by Pinsider sscnz.
Click here to go back to viewing the entire thread.

#1 2 years ago

Hi All, this is the last of the issues I have found on my new machine. Would really appreciate some input on nxt troubleshooting step.

Symptom:
Backbox GI lamps connected to green and yellow wires aren't working (lamps connected to purple works).
Lower playfield lights (such as inlanes etc.) connected to the yellow wires aren't working.

I have followed the excellent pinwiki guide here: http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Introduction

What I have done so far:

Connectivity tests:
J120 pin 3 to Triac Q14 tab - OK
J120 pin 9 to J115 pin 6 - OK
J115 pin 11 to Triac Q14 pin 1 - OK
J115 pin 6 to J120 pin 9 - OK

J121 pin 3 to J120 pin 3 - OK
J121 pin 9 to J120 pin 9 - OK

Lower board GI Lamp sockets
Lamp socket to J120 pin 9 - OK
Lamp socket to J120 pin 3 - OK

Voltage tests:
J120 cable connector pin 3 and J120 cable connector pin 9 (yellow) - 0v
J120 cable connector pin 2 and J120 cable connector pin 8 (orange) - 6-7v
J120 cable connector pin 1 and J120 cable connector pin 7 (brown) - 6-7v

J121 cable connector pin 6 and J121 cable connector pin 11 (purple) - 6-7v
J121 cable connector pin 5 and J121 cable connector pin 10 (green) - 2.3v Huh?!
J121 cable connector pin 3 and J121 cable connector pin 9 (yellow) - 0v

J115 cable connector pin 3 and J115 cable connector pin 11 - 6-7v

I have also tested related fuses, F108, 107, 106, 109, 110. All good. I'm slightly puzzled why I get half the voltage on the green wires?!

While doing the troubleshooting I also found the J115 pin 10, 11 and 12 are slightly melted (black) so I need to order and replace the 12 pin connector, cable and board. But, going through the test it does look like these are still working and connect to the correct places.

J115 seems to have all the right voltages and I do have connectivity between J115 pin 6 through the F108 fuse to J120 pin 9 as well as from J115 pin 11 through the Q14 Triac and then down to J120 pin 3. hmmm. I guess a possibility is that the Q14 Triac is broken? Is there a way to test this?

Any input/guidance is appreciated! =)

Thanks all!!

/Stefan

#12 2 years ago
Quoted from jimy_speedt:

Hi,
I would check after connector replacement, but as a first test, are you well testing in Vac and not Vdc ? It makes me think it is the case as you measure pin by pin.
In game mode, do you get AC voltage of 6,8Vac on the 3 circuit of j120 (measure between the 6,8 Vac pin and the corresponding return on the connector). Also on J121 for the backbox.
the triacs should be good, there is one per circuit, it would be strange if multiple triacs are out.
The burned connector should be the issue

Yeah, I think you are right. I shouldn't really spend too much time until I change the two potentially faulty connectors (J120 had a terrible repair job and pin 10, 11, 12 on J115 are melted). I will order a new 12 pin connector today. I don't get any voltage on between the yellow wires on J120/J121. I get half the voltage on the green wires on J120.

THANKS!!! =)

#13 2 years ago
Quoted from Thunderfoot:

V=I x R....mr ohms law....check the resistance of the yellow pin from the connector back to the board! You already stated the connector is burnt! Most likely the wire has suffered heat damage as well. The harder the current has to work to get through the yellow wire and burnt pin/connection the low voltage on the end is the result. Check the resistance, then check the voltage on the input side of the connector...probably the voltage drop you are missing resides in corrupt yellow wire and connector....back up...follow the resistive path and ya gonna see exactly how or what is acting like a big resistor in the circuit. Just a few ohms makes a big difference...compare the resistive value to the other pins in the connector....really ya should have checked resistance first!

Ah of course. I'm beginning to remember my electrical engineering courses lol. My goal is to get this machine in top shape so will replace the connectors but I'll test the resistance in the weekend. Thanks!! /S

Promoted items from the Pinside Marketplace
$ 12.00
Electronics
Yorktown Parts and Equip
$ 209.00
$ 135.00
Lighting - Led
LED OCD

You're currently viewing posts by Pinsider sscnz.
Click here to go back to viewing the entire thread.

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside