IGT PE+ PUSH BUTTON PROBLEMS

[JonesK]

  I have a problem with my IGT PE+ push buttons. When I go to the I/O test page and press button 2, it activayes button 5. If I press button 3, it also activates button 5. If I press button 4, it activates button 5 too. If I press button 5, it rightly activates botton 5. Button 1 seems to work fine. I have I identified the problem to be on the processor board and NOT the machine wiring because when I swap the processor board with a known good one, the problem stops. Please someone help!!!!
JonesK

[stayouttadabunker]

Actually, It appears your button harness is okay and wired correctly really...
It sounds like a ground short on the board.
Or a chip is not seated good in a socket.
Try re-seating all socketed chips on the MPU board.
Make sure you don't fold any chip legs underneath!
Let us know how you make out!

[knagl]

I ran into this problem on one board.  In my case, I had a physically broken resistor in a bank of resistors diodes on the MPU board (for some reason, it's pretty easy to damage that corner of the board when inserting/removing it from the machine).  Look very closely in the area I circled for any physical damage (I didn't even see it on mine at first until a friend pointed it out), and then if need be test the resistors diodes in that area for one that isn't working properly.  Replace the broken resistor diode, and that should fix the problem.

(Thanks to Stolistic for the original picture of the MPU board.)

[jay]

You just didn't want to get slammed after that Ebay Picture stealing thread..... LOL

Interesting place... as that is about the same place as the reel resistors for the S+

Thanks for posting this.

[stayouttadabunker]

That's funny, I was thinking the same thing as Jay when I saw that green circle around the resistors.
It's so similar to an S+ MPU board in a lot of ways.
So....I start looking at my PE+ MPU board for cracked resistors...lol
I'm blessed because there's nothing wrong with mine really.
I think it's really great that someone like Stolistic knows this about PE+ boards and was
able to help out knagl...

[JonesK]

Thanks Jay and knagl for those valuable suggestions. You are great. Will post the results after I try it out. Thanks guys!

[JonesK]

I ran into this problem on one board.  In my case, I had a physically broken resistor in a bank of resistors on the MPU board (for some reason, it's pretty easy to damage that corner of the board when inserting/removing it from the machine).  Look very closely in the area I circled for any physical damage (I didn't even see it on mine at first until a friend pointed it out), and then if need be test the resistors in that area for one that isn't working properly.  Replace the broken resistor, and that should fix the problem.

(Thanks to Stolistic for the original picture of the MPU board.)

 

 On my processor board (Assy No. 7570340  7 REV D), there is a pack of doides CR1 to CR18 on the place you have circled in the processor board photo. I have tested all these diodes and they seem OK. I have also replaced RP3, RP4, U1, and U2. Diode D3 has tested Ok. Any more suggestions will be highly appreciated. Thanks

[stayouttadabunker]

Why did you replace U1,U2,RP3 & RP4?
Was there some sort of damage problem in that area?
Are the traces okay?
They are very fine and delicate traces in that area.
Can you post a hi resolution photo of that area?

[Jim]

I would revisit your diodes. the fact that you could get the switch's to respond tells me the opto isolators are good, the resistor pack  has to be good or it wouldn't let the transition from high to low occur. your problem has to be one of the diodes in the matrix. Have you checked them in the circuit? you may have to lift one leg and test them that way. You should actually remove one and get a good reading so you can compair it to the others. forward bias (blacklead of meter on the cathode of the diode , red lead on the anode should read several K ohms) reverse bias (reverse the leads  no resistance at all)
cathode is the side with the line on the end of the diode. the diodes are 1N4148 type. you should only be concerned with CR1,2,3,4,7,8,9,10,11.  My guess is with one of these. The switch presents the low to the diode matrix then to the opto's.  It has to be in this area, either the diode or a solder bridge.

worst case ,you can lift one leg at a time and see which one is causing the problem. if you replaced all the components you said then you must have soldering skills.

Jim
 

[knagl]

I think it's really great that someone like Stolistic knows this about PE+ boards and was able to help out knagl...

I just stole the picture of the board from Stolistic so I could circle it -- it was actually another friend of mine who isn't on here who owns a local shop who was able to identify the problem and fix it for me.  Perhaps it is a diode that is the issue (not a resistor) -- I'm not an expert at all when it comes to board level repairs.  I'll have to dig out my formerly broken board and take a good picture of it to identify exactly which resistor and/or diode was replaced to fix my similar problem.

[stayouttadabunker]

This might explain these particular diodes.
Click on photo to make larger!...>>>

The 1N4148 is a standard small signal silicon diode used in signal processing.
Its name follows the JEDEC nomenclature.
The 1N4148 is generally available in a DO-35  glass package and is very useful at
high frequencies with a reverse recovery time of no more than 4ns.
This permits rectification and detection of radio frequency signals very effectively,
as long as their amplitude is above the forward conduction
threshold of silicon (around 0.7V) or the diode is biased.

In other words...it's a very high-speed switcher!
Here's a link I like very much, on How-To-Test a diode and other components too!>>>

http://www.elexp.com/t_test.htm

Sometimes it's just easier to go out and buy a used board too! 

[Ohio Chad]

Have you changed the button panel mechanisms (new buttons)?  Have you checked you Bet buttons, call attendant, and your hopper cashout?  Usually if your Bet buttons have a criss cross wiring it causes button errors.  If you have never messed with the buttons, then my input is useless.  If the buttons have been tampered with, you need to make absolutely sure all the plugs are set up properly in the button mechs.

[knagl]

Chad-

He mentioned that the problem goes away when he uses a different MPU board, so that isolates the problem to the board and not the switches.

[stayouttadabunker]

I wonder if the "bad" MPU board has a bent pin?

[jay]

The piece of info that I was lost on.

He said the Selftest showed Pressing 1 and 1 closed.
Press 2 and 5 closed
Press 3 and 5 closed
etc

What he didn't mention is that 5 & 2 both closed or just 5        5&3 or Just 5

It almost sounds like the HI line of 5 is shorted to each of the other lines.
In a simple etched matrix someone would have had to drop a large dollop of solder to cause this.

On the other hand I could see that this is all handled in a gate chip and by accidently shorting a lamp or something on the button harness and it fried the chip.

Now which Chip I don't know.... however I would start by that pak of diodes or resistors and start swaping out "little chips" one by one with a known good board until it starts behaving....... 

[knagl]

I know that hold 3, 4, and 5 are on the same common line -- 2 might be as well (edit: yes, it is -- hold 2-5 use the same wiring).  I need to dig out my board, but I have a board that had this exact problem, and it was a broken resistor diode.  The symptom is that when you'd press hold 3, only hold 5 would show as closed.  If you press hold 4, only hold 5 would show as closed.  If you press hold 5, hold five would (correctly) show as closed.

If I have time when I get home tonight I'll dig out the board and take a picture of the repair, which should isolate the problem even more than my large green circle.

[JonesK]

I would really appreciate Knagl if you check out that one for me. Thanks

[Ohio Chad]

I am sorry for the lack of input, the question should be...With the new board did you check all buttons, not just the ones that were failing?  If the buttons are not wired properly, when the replacement board is in and you haven't engaged the function per button, it might not create the short.

[knagl]

JonesK-

Here is the board that I had repaired to fix the problem -- you can see that the 1N4148 diode at CR1 is what was replaced.  We used a spare parts board and just took one of those off the parts board and put it on this board to repair it.