S-Plus display board, displays nothing but dark, no reading, no nothing

[Jackpot]

I.G.T. S-+ with a bad horizontal door reader display board, I replaced it with a new one, still doesn't work, replaced the MPU still nothing, replaced the mother board, still doesn't work, checked all the fuze's, all good. I think it may be in the display board harness? I get no credits or coins played, coins win amount, all dark. Once while working with the old display board it came on and only displayed a bright "9" that did nothing while playing it, but that is gone and dark now. The only light that works is the light behind the coin amount. I looked the wiring over and the wiring plugs, but everything looks good by eye. Where do you think this problem might be, maybe in the wiring harness for the display board?

Well done the 4th so now it's time to do the 5th......

Thanks...

 Jackpot

[jay]

You are most likely dealing with a power issue.
#1. Check for stiff reels - with the power on, can you spin the reels easily by hand or are the reels stiff...
I am suspecting they are loose.

#2. Check your fuses. Pull them out and with a meter check that you have continuity through them.
If you have a bad fuse replace.

#3. The most likely culprit however is a bad or shorted harness.....any chance you installed a topper recently.
It is easy (really easy) to get a short as the hole where the candle goes is very sharp and the topper harness wires can short.

[westec1]

Check your power harness connection at the mother board
it's circled in red on the attached pic,
check to see if the power connections are turning brown, if they are, this is a sine of a bad connection
try to move it around a bit to see if the display comes on, if so try to clean the contacts
or contact one of our vendors for a replacement.

Wes

[Ron (r273)]

To add to westec1 suggestions make sure you turn that plug around and check the backside,
that's where it shows up first.

Ron (r273)

[Jackpot]

I'll take a look at the power supply plug, I have seen these blow before on the IGT S-Plus and know they can be faulty... Did I say that this machine works fine?? Plays and pays out, stores credits somewhere, and can play on credits too, no new top candle or toper, as stated above.  It's just that the display is dark but the machine works as it should. Do you think this power supply could still be a possible problem. Also, I did test all the fuses and with a meeter, that is the only way I will test a fuse, with a meeter, as they fooled me once before.
Thanks!
Jackpot 

[jay]

If it plays / pays it sounds more like a display board or the harness / ground that feeds the display board.
I doubt it is a fuse at this point.

Its either not getting power or its shorted...or since the whole thing is out it could be a single ground wire missing......

[Jackpot]

Thats is what I am stuck on, I put a brand new display in it, and it's dark too.

[StatFreak]

Since you've replaced your MPU, motherboard, and display board, I would say that it's time to replace the harness, as you first thought.

[stayouttadabunker]

The "bad display"...does it work in a known good machine?

[Jim]

Since your game works O.K.  it's not the power connector, (usually the denomination lamp will not come on when the power connector is bad). and it's not the fuses' (your game would not work if any of the three were bad). I have seen this problem before- it was the plugs on the motherboard being put in the wrong place. I recall it might be the meter plug  being put in the reels plug. both are 6or 7 pin connectors. I'll have to look at the wiring diagram tonight.


Jim


p.s.  the display could be bad,or the the connector on the left side of the display could be suspect. the connector on the right side controls the denom. lamp and the insert coin and coin accept lamps.