WH20 random rebooting

[pokermachine]

I will just throw this out there as i had the same issue with my WH2O resetting.
Most people would think this is a no brainer silly mistake  but i never thought the screws that hold the board in place actually earthed the board... i thought they were just to rest the board on... it was only after multiple pages of reading on this site someone said " tightened the screws and has good earth"..... Bingo.... tightened the screws and no re sets ever since..... may be your case too... screws come loose and its not a random reset its just when the board looses the earth and turns off.
Hope this helps

[Pintoxicated]

+1 to tightening the screws on the boards.  I had issues years ago with a machine that kept on losing sound.  It would fade out and then come back and fade out again.  Ended up being a lose screw on the power driver board.

[Agentbarry]

Cheers for all the ideas, i left the machine doing a auto burnin and no resets yet, will see if the fault comes back

[johnwartjr]

I've been fixing a great deal of WPC boards as of late.

In my experience, resets are most often caused by cold solder joints or connectors.

You would be amazed at how much the +5 volt supply will come up by doing some simple things. Removing the solder on the 2 legs of Q1 and resoldering. Resoldering the legs of BR2. Resoldering C4 and C5. Resoldering J101 and F113. Note that I didn't say *reflow*, I said *replace*.

I've removed all the caps on a WPC driver board, and thrown them on my cap tester. On many 20 year old WPC driver boards, the caps are all fine.

There are some where the caps and bridges do fail. But, those are a whole lot less common.

The whole 'replace BR2 and C5' thing has worked for so many people because when they replace BR2 and C5... they remove the solder, and replace it.

I've fixed my fair share of boards, too, where someone took the 'replace all the bridges and caps' method, and managed to run a whole bunch of plated through traces. They ended up spending twice as much as they would've, if they'd just sent the boards out to begin with.

Don't get me wrong, we all learn somewhere. But I try to convince people to solder on some old junk boards before diving into pinball boards. Mess up an old alarm clock or something, learn, and them apply what you've learned to your pinballs :)

[robm]

I agree with John above - i am no expert on this stuff, but have been doing quite a few repairs on the possum pins and a few for mates around town.  Most reset issues i have come across are header pins that need to be replaced, then resoldering components.  I have no way of testing caps,so cant say if the ones i replaced needed replacing, but i think only once have i had a bridge fail. 

Of course the counter argument is that since you have the board out, why not replace all components that have potentially reached their lifespan...i will do that if i am doing repairs for someone else, but for my own, i'm happy to leave them and repair when required.

[Agentbarry]

the fault has not come back in the last week and its been getting played quite a bit. i dont think the caps were bad, i do think that the solder was the main cause of all the problems
fingers crossed it stays working

Thanks again to everyone for all the help

[Homepin]

Great that it seems to be cured.

A couple of points that this thread has raised. One is tightening of the mounting/earthing screws. This is not only a good idea but is actually required in Zacs. I had a buyer of a Zac MPU say it had worked fine for a year but suddenly started going beserk and blowing fuses. Naturally the first thing that the finger gets pointed at is the replacement MPU  .

Turned out to be loose PCB mounting screws on the power supply PCB causing the random problems and fuse blowing.

The second point is RoHS (Removal of Hazardous Substances) or "lead free solder". Thanks primarily to Europe, practically all new electronics for the past 10 years has been made using this hideous stuff. That coincides with a drastic drop in the reliability of almost all electronics from TVs to Pinball machines.

This will get worse and quickly as RoHS solder ages poorly and seems to break up after just a few years creating dry joints that simply cannot be corrected on some of the microscopic parts used these days.

Be aware that this RoHS issue WILL affect new pinball machines probably about NOW!!!

[Zedman]

I'm a noob at pin repair but have been doing bench repairs/ service to varied ewuipment for a long time. I'm sure other techs with more pin experience have given good advice.
Reseating board connectors has worked in the last three pins I've seen with resetting issues.

This work is also done when replacing bridge rectifiers.

I agree with Mike, lead free solder is problematic and I just don't seem to get off on the fumes as much! ;-) Z