(Topic ID: 89172)

Flasher Problem On Road Show

By Captain_Tilter

8 years ago

Topic Heartbeat

Topic Stats


Linked Games

#1 8 years ago

Hi you guys,
So I purchased a road show in need of a little love and after makeovers for red and ted, playfield touchups from someone driving a few 5/8" screws threw the playfield, etc.... everything is finally looking good but I have one problem left that I could use some advice/input on.. The little flipper flasher, left ramp flasher, and the 2 white flashers in the back are stuck on.. My immediate response was to replace the transistors for these flashers in question. I did so (without checking them of course) and the problem still persists. I have pulled the Aux driver board and checked all transistors, diodes, resistors, pre-drivers and all test good, so it seems that the U1 20 pin chip (i.c74ALS576) would tie all these flashers together and need replacing. Would everyone else agree on this or am I missing somewhere else to check first. Thank you for your time as I am feeling a bit stumped.

#2 8 years ago

Forgot to mention that I checked that no wires are grounded out, and the ribbon cable is seated correctly as well.

#3 8 years ago

Bump for hopeful advice.

#4 8 years ago

Can you make sure that the signal is high coming from the previous chips? Because I'd make sure of that before replacing it. Don't know what transistors off the top of my head, so I can't tell you which line specificly.

#5 8 years ago

OK so replaced the i.c chip tonight and ..........that's not it. flashers still on. Not sure what you mean by testing the signals CadillacMusic could you elaborate because I am pretty new to trying to fix these things. Also should I start looking at other areas besides the Aux driver board? Thanks for any suggestions as I am officially frustrated. Also not sure if this is relevant but the game is a re-import.

#6 8 years ago

My advice is to look at the entire path between the flashers and the Driver board. If replacing the driver transistors and U1 didn't fix it, you need to look at the other components in the line.

Something is causing those lines to short to ground. Have you tested the pre driver transistors? For each flasher, there is a pre-driver transistor Q12 for Q11, etc. Have you tested those with your multimeter yet? Black on ground braid and red on the outside legs with your MM on diode test. You're looking for a reading between .4 and .6. Test each pre-driver the same way to make sure you don't have a dead short there.

I would start there and report back.


#7 8 years ago

Thanks for the info Marc. I did test those and everything tested good. Something I noticed tonight however in the flasher test mode was that after opening the coin door while running the flasher tests the flasher do not immediately stop as they are supposed to.... rather they just flash a few more times and fade out and stop over about 5 flashes...... Could this be a possible clue to the issue? This happens with all the flashers not only the ones stuck on. Thanks for any info.

#8 8 years ago

Next up is to track the logic signals from the CPU board to the driver board. I will pull the schematics tomorrow. Do you have a logic probe?


#9 8 years ago

Have you tried swapping boards with your WCS? The driver boards are the same, and flipping the WPC-S CPU isn't that hard; you just need to pull the game toms and security chips. That will narrow it down a lot.


#10 8 years ago

My MM has a logic probe setting that only shows low (less than 1v) or High (+1volt). Not sure of I need something more specific as I have never used this setting before but hey that's how you learn right! Thanks for your time and response.

#11 8 years ago

Damn, that's a good idea as well. I am gonna try swapping those tomorrow!

#12 8 years ago

Try the board swap first. I have a hunch this is going to be the CPU board. Those flashers are CPU controlled and something is telling them to stay on, and it's likely upstream of the U1 as you've already replaced that.


#13 8 years ago

Thanks Marc I will try this tonight and report back.

#14 8 years ago


#15 8 years ago

Been busy with work stuff so hopefully going to put some time into this soon.

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