Stupid S+ question

[Neonkiss]

I have a few S+ CPU's that I put away about 3 months ago after I tested them myself in one of my machines. I marked them with tape and wrote the date they were tested good on them. I have a member here ask me if I still had some boards so I went back to re-test them before sending them out. All I get is a 61 and no matter what I do, I can't clear the 61.
If I put my original CPU in the test machine, it works fine. Then move the SS and SP chips to the pre-tested board and I get the 61 that will not change to the 61-1
I then decided to use a clear chip, but again only 61 and no change to the 61-1
I put in the original CPU and now that one will not go past the 61, since I used the clear chip and wiped the E2 chip.
I changed the motherboard and again only the 61
I finally, unknowly got a 61-1 and the machine played with the spare Motherboard and one of the pre-tested CPU's that would not work before. I then put in the original CPU and chips, but you guessed it.... just the 61 

Things I do know:
Always using the same SS and SP chips
All parts were pre-tested before tagging and putting away
Batteries are all good and installed properly
Wiring in the machine is like new (machine date 1998)
Test button works flawlessly, as when I put in a clear chip you have to press the button to initiate the cycle.
Door optics are good, Cash can is seated and cash door is closed.
Motherboards are both good as I did have it working with both of them at one point tonight.

Has anyone ever experienced this in a machine before?

[Sunrise Side]

I had some problems similar to this. Not sure if this was the actual fix for mine as I wiggled things around also, but give this a try. Remember which DIP switches are on. Then go through and turn off all the switches and then turn them all on. Do that 2-3 times. Then set the switches to their original position and try the board.

[GOS]

 i think i had this problem too - i  changed out the SS or the SP chip - and all was well 

[Neonkiss]

Thanks all, I had to walk away from it the other day.
I'll try all suggestions and post back the results.

[CVslots]

Have you tried a small load of explosives? I hear this works good to "fix" problem machines...

[Badbaud]

Thanks all, I had to walk away from it the other day.
I'll try all suggestions and post back the results.

Have you checked your battery?

When I fix S+ boards for stock I cut a trace from the battery and put a 2 pin PC jumper in series. This way I can remove the jumper before putting the board in storage so the battery has no load on it and lasts longer.

Then jumper the two pins when the board is ready to be put into a game.

The battery is still producing voltage to the RAM chip even in storage and can go dead sitting on a shelf.

[Neonkiss]

Thanks, battery is fine, voltage is 3.6 S+ boards do not chew up batteries in storage like the Bally machines.
Roz, tell me more about these explosives you speak of