Help with Sportcraft Turbo Hockey no sound

[damagd]

Sound went out on it a while ago, but scoreboard still works.  I'm assuming that it's something with the control board, but not really sure how to troubleshoot.  It has a separate button to turn the sound on and off as you can see in one of the pics.  Have a multimeter, but not sure how to check anything or what to check.  Wiring looks ok everywhere.  Would appreciate any help, thanks.

[RandyT]

Maybe the switch went bad.  But given the lack of components on this board, the sound circuitry is elsewhere and any number of things could be wrong, depending on what is there.

Before you do anything, find the speaker and check any wiring or connections to it.  Bear in mind that even if the connections are good, speakers do die on rare occasions, especially if they are of a very cheap variety.  But it's usually not likely.

To discount the switch as the problem, you just need to make sure the power is off to the machine and set your meter to it's continuity or "beep" mode.  Probe the solder points of the switch while actuating it and make sure that the expected connection(s) between the points is occurring.  i.e. if the meter beeps (or displays zeroes in resistance mode) then the switch is probably ok.  Based on your photo, it should be simple to see the ones of importance by looking at the traces going to the switch terminals.

From there, do the same with all of the wires between each of the PCB's.  With that out of the way, you could probably assume that a component on the main PCB has failed, in which case, it won't likely be a simple matter to debug and repair.  But you can give all components and their solder connections a visual inspection.  You may get lucky and find a cold or poorly made solder joint that has broken and can be re-soldered.

[damagd]

Thanks for the response and diagnostic tips. I'll give it a look as soon as I get a chance and get back to you.

[damagd]

Ok, I did the test on the switch.  The switch has 6 pins going through the board.  The two on the right that are not connected through the circuitry of the board had different readings when the switch was manipulated as far as continuity goes.  So I'm assuming that means it's working.  What about the round little tannish thing that I have circled in the picture?  I believe it's a capacitor maybe?  It is connected to the circuitry of the switch.  Could it have gone out, creating the problem?   

[RandyT]

If the pads/contacts on the right are not connected to anything, then they don't affect the circuit.  I.e. when they are connected, it just creates an open circuit.  Are those the only ones which show a connection with the middle pads when the switch is operated? If so, then that would be suspicious.  If I were to guess, that switch just connects the left and center set of pads.  Does it do that?

Also, does the switch stay down when the circuit is closed and pop up when open?  Again, just a guess, but without knowing more about the circuit, it looks an awful lot like the sound switch is passing power through to one of the wires on that ribbon cable leading off to the sound circuitry.  The disc capacitor appears to be a filter cap, so that shouldn't affect anything. 

[damagd]

Thanks for the help.  I've numbered the pads to provide clarity.  So when the switch is up, there is connectivity between 1 to 2, 3 to 4, 5 to 6, 3 to 5, 4 to 6, 3 to 6, and 4 to 5.  Those are the only connections when touching all possibilities.  When the switch is pushed down there is connectivity between 1 to 2, 1 to 3, 1 to 4, and 2 to 3.  That's it.  I'm assuming that the switch is working based on the results when it is either pushed down or up.  If that's true, then I guess my next step would be to access the speakers.  I can take the arch off of the table and separate the two black posts from the grey plastic speaker assembly, but it is snapped together tight and there are no screws holding it together.  I don't want to break it, so maybe I will pick up a plastic prying tool kit that they make for computer bezels and phones.       

[RandyT]

Thanks for the help.  I've numbered the pads to provide clarity.  So when the switch is up, there is connectivity between 1 to 2, 3 to 4, 5 to 6, 3 to 5, 4 to 6, 3 to 6, and 4 to 5.  Those are the only connections when touching all possibilities.  When the switch is pushed down there is connectivity between 1 to 2, 1 to 3, 1 to 4, and 2 to 3.  That's it.  I'm assuming that the switch is working based on the results when it is either pushed down or up.  If that's true, then I guess my next step would be to access the speakers.  I can take the arch off of the table and separate the two black posts from the grey plastic speaker assembly, but it is snapped together tight and there are no screws holding it together.  I don't want to break it, so maybe I will pick up a plastic prying tool kit that they make for computer bezels and phones.     

Ok, switch is fine.  I think you need to look at the pcb responsible for generating the audio before looking at the speaker.  Make sure all of the wires and components are properly soldered down and nothing on the PCB looks like it has burned or experienced excessive heat (usually indicated by physical damage to the component, like browning, charring, holes, etc.)   Keep in mind that these are just the simple things to look for.  It's very likely that a component has failed somewhere on that board, and could require a schematic and/or very specific and possibly unobtainable parts to effect a repair.  And components can be dead with no visual indications that this is the case.

*Edit*  Also look for corrosion on any connections, no matter how slight.  This can build up and eat it's way between solder joints, especially in the case of lead-free solder.  Most repair folks will hit any crusty looking joints with leaded solder after cleaning, just to ensure a good connection.