IC Corrosion and error messages

[ljwayne5451]

Good Sunday, I am still working on my S+ MPU and it was determined my problem with reel #2 not spinning (I did swap reels and the problem stayed at #2 reel position) I am getting ready to remove the reel #2 stepper chip (U2) and noticed on ALL the reel stepper chips a corrosion looking buildup on all of the chip legs and in some cases looks to be touching from leg to leg. I find this on no other chips on the MPU (No Battery Problem) Can anyone tell me why these chip are like that. Has anyone else seen this on the reel chips? U10=1 U2=2 U11=3 My replacement IC has not arrived yet.


Thanks, Larry

[Stayouttadabunker]

A picture of the reel chip legs sized at 1000kb downloaded here would definitely help our members help you.

[ljwayne5451]

photo posted in original message

[Stayouttadabunker]

There was some flooding down in the south at some casinos in Louisiana and Mississippi....maybe that's where your machine came from or at least the MPU board?

[Sunrise Side]

You may want to check the traces on the notched end of the IC for corrosion under the green sealant that is on the traces as I some black coloring of the trace. Remove the sealant from the trace and be sure the trace is in tact. May have to get a MPU if traces are damaged?

[ljwayne5451]

The board looks very good the only discoloration is on the legs of only the Reel stepper chips no where else. The rest of the chips and board are fine. Just find it kind of odd.

Well, Something must have been spilled on the board at some point and got under these chips, pop maybe, the legs of only these chips are like that and when i took the U2 chip out there was a small pool of dried brownish/black substance under it and I am guessing if I pull the others I will find the same. Traces look good but I am still checking them. It's something that affected the chip legs but nothing else.


Thank you
Larry

[ljwayne5451]

Am I correct on which reel stepper chip is for which reel on my 10MHz board? In my original message.

[Tilt]

Am I correct on which reel stepper chip is for which reel on my 10MHz board? In my original message.

Yes.

[Stayouttadabunker]

When I repaired mine, I installed sockets first, then I just pushed in a driver chip.

Makes it easy to change out later on...plus you put zero heat to the chip legs.

[ljwayne5451]

I will be doing the same, Thanks

[dailey]

That green sealant on the traces is solder mask. It looks like moisture got under the solder mask and is corroding the traces. This could lead to current leakage or shorts between traces, if it isn't shorted already. I would replace the board. It's not worth the headaches it could cause later on.

[ljwayne5451]

I indicated that the #2 reel was not rotating with the other 2 reels when the game was reset or started up. I have switched the reels and the problem always stays with the #2 position so it is not the reel. It was suggested that the reel driver IC may be bad so I have replaced the IC in U2 with a socket and replaced the IC. The reel does what it did before, it does lock in place so the stepper has a hold on it but when the other reels move the #2 reel still does not rotate and it generates a 42 Error. I have checked the harness pins and connections (although I have not put a meter on them yet) and don't see any problems.Is there anything else I should do or check? 42 in the window but still flashing Insert Coin. Candle slow White and Fast BlueActually I don't know the best way to check this. Where can I get a harness if I need one?Thank you,Larry

[Trisail]

Some info -

Check the harness with a meter, wiggle the wires along the length when you are checking continuity, stranded wires could have one strand good and meter will show continuity. Also check for shorts between the wires, not just each wire is good. ( Most likely wire break points are - sharp bends, bad crimps on pins in connectors, breaks at connectors where the wire goes into the connector, ty-rap or fastened cable joints. ) I pull on wire at connectors to see if they are bad, if they stretch the insulation and break, they were bad. Obviously the pull strength is the controversial question on wire pulling - what is pulling too hard. Experience helps a lot with this.

Could be backplane PCB problem, if the main board is good. Not sure if you have another mainboard to try.
The other chips that could be bad for Reel 2 are - (going backward from the driver IC)
U23, U27 or U22 or U12, U21, U25, U33, U25, U13, U34.

So you have a few other IC's that could cause the reel not to spin.  How far do you want to go with chip replacement? If you can use a meter, get on the board to check signals you may be able to determine which chip(s) of the 10 above could be bad. This assumes the traces on the board are OK, and the socket you installed has all the pins connected, mostly meaning you did not cause a problem when replacing the chip. ( Not trying to say you don't know what you are doing, just that I am experienced on board repair and there is always the chance you do more damage than repair when replacing chips)

A known good main board would tell you if yours is bad and the backplane board is good or bad.

Hope this helps.

( Probing/troubleshooting the main board in the machine would be possible but would be somewhat difficult, not impossible. Be careful  )

Tony

[ljwayne5451]

Ok, I will go through it again and see if I come up with anything. I don't have another board but I did order another board since it was not too expensive to see if it is the board. I do have and Fluke meter and I know how to use it. How do I go about the checking of IC signals? The socket I put in seems to be properly installed and I am getting the same results after installing the new IC where the reel is locked in the hold as it was before I changed the IC. The traces on the board look good and all the pins are good on the MPU boards J1 and J2 are good. Just to be sure it was Not the SS reel chip I also put a different SS reel chip in with no change. I am fairly new to the electronic slots, my background is mostly mechanical and electromechanical slots. I do understand elementary electronics but have a lot more to learn I am sure.


Thank you
Larry

[ljwayne5451]

That green sealant on the traces is solder mask. It looks like moisture got under the solder mask and is corroding the traces. This could lead to current leakage or shorts between traces, if it isn't shorted already. I would replace the board. It's not worth the headaches it could cause later on.

Hi Dailey, I have tested the areas that may have a problem but the traces seem to be ok. I see what you are talking about though and there are some very dark areas over the traces. You may be right that some of the smaller traces were damaged by the corrosion around the stepper chips. It is very hard to check. There was a dried crusty area under the chip. I did order another board and I will see what happens when it comes in.


thanks for the help
Larry

[ljwayne5451]

Good day to all, well I just now got my new S+ MPU board. Now to start with

1. The jumpers are set to be the same as my old board.

2. There is no chip in U18 (IC Duart) of the new board so I will move it from my old board, correct?

3. There is a chip in U49 (sound chip?) Should I move my old sound chip to the new board?

4. I set DIP switches to match my old board. 1-3 are ON and 4-8 are OFF.

5. Is this a case to do a Clear before putting in the Game chip?

6. Will I have to set up for 25 cents?

Anything I missed?? Any other suggestions or thoughts?

Thank you,Larry

[Trisail]

Put the U18 form your board in this one.
The U49 sound chip is programmable so maybe need your old one. I would put it in after you check the board. See if the sound gives you any problems first.
Not sure if clear is recommended at this time. You should know when you test if you need to do a clear.
You will need the .25 clear chip.
Good luck and hope it works.

Tony

[ljwayne5451]

put the ic 18 in and the game and reel chip....reels lock but no displays...put in clear chip same result.


Not sure what to think now!!

[Stayouttadabunker]

I'd return that MPU back to seller and tell him it's incomplete.

[ljwayne5451]

good afternoon, Well Tony (Trisail) was kind enough to offer to help me with the problems I was having. I gave him a call and he went though it with me step by step. I had moved the chip in U18 from my old board along with the game and reel chip to the new MPU. After doing so there was no display at all. The reels lock, that's it. Tony said to remove the chip in U18 and try it again and it worked!! Even though it was in my old board the new board did not work with it installed. We continued on going through some of the testing and finally got it to take coins and operate normally. I still need to work on the DBV as it is not taking bills. Also the reel strips seem to be out of position so I need to see if they were installed properly


I appreciate being part of this community and grateful for all the help I have received the last few months and a special Thank You to Tony for taking time on the phone to help me out!!


Thanks,
Larry