Led Display Board

[Rich B.]

Okay, here we go. I bought an IGT S plus Red White and Blue two months ago. It worked fine but I thought it could use some cleaning up. I bought a new 6 volt LED button kit for it and began the replacement process. I started with the small buttons on the right. They worked fine. When I replaced the Bet Max button and powered up the machine the LED panel that controls the credits, win meter, coin in, denomination, insert coin, and coin accepted lamps began to pulse and went out rendering the machine inoperable. I freaked out and power off the machine. I switched back to the old max bet button and turned the machine back on. Nothing! I power it back off and remove MPU to check for fuses and burn spots and can't find anything. Replace the MPU and power it up. Bang! Working again. So I decide to proceed with swithching buttons. Power up and the panel starts to pulse and goes out. This time I cannot get back on. I replaced all the old buttons in the machine thinking maybe all the working bulbs was too much draw for the panel to operate correctly. With the old buttons still nothing. The machine upon power will light up and the DBV cycles. That is as far as it goes I have no lights on display board. Checked the power to board with voltmeter. There is 4.1 volts going into the incandescent side of the panel. When I probe the denomination light socket ( it is the first in the line for power on the board ) it has no power when the light bulb is inserted into socket but if I remove the bulb it has 4.1 volts. There is also no power to the other 2 sockets in the line when the denom. light is inserted into it's socket but there is power to them when the denom. light is removed. Is this normal? Could this board be fried? Is 4.1 volts too low? Could it be the MPU? I noticed before messing with any of this that the denom. lamp was weak and it dimmed whenever there was another lamp flashing or any sort of electrial draw in the machine. HEEEEEELLLLLLLLLLLPPPPPPPPPP!!!!! This is my first machine but I have pretty good hold on basic electrical. I was thinking a shorted wire but it seems that I would get some sort of flicker when giving the harness a little jiggle and that would not explain why it worked after removing the MPU and replacing it.

[knagl]

Welcome to the site, Rich!

 

I'm not terribly knowledgeable about component level repair.  In your shoes, I'd personally replace the LED display board in the door and/or the MPU board to fix the issue, but I'm sure that some of the members here who have more experience with the electronics of the machine may have some ideas for you, so sit tight and wait for some other replies.  It sure seems odd to me that the denomination socket would lose power once a bulb is installed into it.  It's my understanding that the socket should always have power if the machine is powered on and the power supply is good, even (I believe) with the MPU board removed (can someone else confirm that?).  I'd suspect that something is amiss with the LED display behind the reel glass.

[stayouttadabunker]

Okay,
The 1st thing I'd like you to do is take out those LEDs from the buttons and display panel.
The machine should function well without bulbs.

If you take out all the LEDs, does the display panel come back on with the "Winner Paid", "Credits", and "Coins Played" ?
I want to see if it's the LEDs that are causing this.

It's possible that the LEDs you've gotten are drawing too much or backwards or something...
We want to see if we can save your display.

There's two connectors that go into the display board.
Make sure they plugged in good.

The buttons use #259 wedge bulbs
while the display panel uses #86 mini-wedge bulbs.
I made this MAX Bet Button wiring diagram.
Please compare with yours...
Click on photo to enlarge! >>>

[Jim]

since you have a electrical background:  check fuse F2 8 amp   this supplies the 7vac .   the 7VAC  goes from the transformer to the mother board via the cable that causes all the problems with power distribution in the S+. check this connection at the motherboard. this could be one problem.

the denomination lamp (the lamp that lights up the 25 cent decal) should be on as soon as you turn on the power. even with the MPU removed, this is a direct connection from the motherboard to the LED board. It is 7VAC. 

lets get the 7vac at the denomination socket first.

Jim

look at this link for a picture of the cable
http://newlifegames.net/nlg/index.php?topic=12194.0

[Rich B.]

Okay, I checked the voltages from the transformer to the board. The 2 orange wires have 12.6 and 12.7 volts respectively. The voltage is the same on the harness and the pin on the backside of the motherboard. The Blue wire w/ orange stripe has 1.1 volts on both sides. The gray is negative. The green wire 5th from right has 7.6 volts on the top and zero on the bottom. It is slightly discolored around the white plastic. Oh Wait a minute. I pressed firmly on the plug to pin and the lights came on but they go back off when I take pressure off. I pressed alittle firmer and the LED panels lit as well. I had my wife check the front panel while pressing on the plug and it is giving a 49 code. Reel mechanism disconeected. I am going to do some surgery on the wire connector and let you know what I find out. Thanks. I have hope again.

[Rich B.]

LAAAAAAAAA LA LA LA! YOU ROCK! Did some surgery on the cable and roughed up the pin with some fine sand paper. Reconnected the cable and BAM! Put the door back together and replaced coin hopper. Power up and shut the door, hold my breath and the reels reset to previous spin. YES! Cleared the 3100 code and it came back to life. It's alive! Alive! Thanks so much for pointing me in the right direction. I knew it had to be something simple. Now my question is this. Was this coincidence or did the LED buttons cause this to overheat? I am just replacing the button inserts and leaving it alone. Again, thanks to all who helped with advice. I gotta go play my machine now!

[stayouttadabunker]

When you jiggled the harness and connector earlier, it briefly came on.
Gotta be a broken wire right at the edge of the receptor pin right where it's crimped.
Tug on the vinyl covering right at that point and see if it moves or stretches away from the pin itself.
If so, the wire is broken or on like maybe 1 or 2 strands.

Using a tiny pin...push down on the metal tang on the molex connector.
That will enable the receptor pin to slide right out for better inspection.
Where repaired, make sure that tang you've bent is pulled back up so
it locks into place when you re-insert it into the molex housing.

Sandpaper or "De-Oxit" does wonders for oxidized contacts...