Tempest help.

[jkoolpe]

Bummer to have to resurrect this thread, but this same Tempest went down again...I swear the game is jinxed!

Anyway, it's not getting the +5V again.

But I think I figured it out...again brought the gameboard, A/R board, and power brick to put them all in my working Tempest. Got the same symptom...then tried my working A/R board and still no +5V. And for both A/R boards, the +10.3V was missing. Then put back my working power brick, and sure enough the game came right up, no problem.

So that means it must be the power brick, and I'm pretty sure it's the bridge rectifier that's gone south now. I did some testing/comparisons between the BR in my power brick versus his brick (diode testing with my DVM), and the latter definitely gave some different/off readings (assuming I'm testing it properly).

I have a replacement BR at the ready...just want to make sure I install it correctly since the tab orientation is a little different from the original and the only marking on the new BR is for the positive tab.

I assume I hook up the wire currently attached to the tab marked "+" to the same "+" tab on the replacement, and then remove the original wires and re-attach them to the remaining tabs, one-by-one, in a clockwise fashion to the new BR?

As I understand it, the "+" tab should be directly opposite to the "-" tab?

Again, just want to make sure...

Jon

 

[andrewb]

Bummer to have to resurrect this thread, but this same Tempest went down again...I swear the game is jinxed!

Anyway, it's not getting the +5V again.

But I think I figured it out...again brought the gameboard, A/R board, and power brick to put them all in my working Tempest. Got the same symptom...then tried my working A/R board and still no +5V. And for both A/R boards, the +10.3V was missing. Then put back my working power brick, and sure enough the game came right up, no problem.

So that means it must be the power brick, and I'm pretty sure it's the bridge rectifier that's gone south now. I did some testing/comparisons between the BR in my power brick versus his brick (diode testing with my DVM), and the latter definitely gave some different/off readings (assuming I'm testing it properly).

I have a replacement BR at the ready...just want to make sure I install it correctly since the tab orientation is a little different from the original and the only marking on the new BR is for the positive tab.

I assume I hook up the wire currently attached to the tab marked "+" to the same "+" tab on the replacement, and then remove the original wires and re-attach them to the remaining tabs, one-by-one, in a clockwise fashion to the new BR?

As I understand it, the "+" tab should be directly opposite to the "-" tab?

Again, just want to make sure...

Jon

A BR is just four diodes in a diamond pattern. So you just use the diode test on your DMM to test them, with the wires disconnected. You should get a ~0.7V drop between any two adjacent terminals in one direction and not in the other. If any are open or shorted, it's toast.

And yes, + goes to +, - is the opposite terminal, and the other two (the AC inputs) technically don't matter, i.e., they can go on either way, however the wires will usually prefer one orientation.

Also, use some thermal grease when you mount the new BR, if there isn't already some there.

If it isn't the BR, it's either the big blue, or you have a burned connector on the fuse block. These bricks are pretty simple, and that's basically all there is for the 10.3V circuit (aside from the transformer, but those almost never fail.) Make sure the main 7A F1 fuse is good, and that you have 120V into the transformer as well, if for some reason you still have issues after the new BR.

 

[ArcadeTechGW]

Check the fuses. Meter each one out, out of the circuit.

If you fiddled with the big blue, if you pull it too far up and the bridge rectifier lead stubs hit the underside of the metal cover, you will have a short.

Make sure your big blue and bridge rectifier board have at least a 1/2" from the metal case.

 

[jkoolpe]

So to (again) wrap this up .

It turned out it wasn't the BR. I tried a new one, but still got the same results (no +10.3 to the A/R board, and on +5V to the game board).

So what was it this time you ask?

I'm a little embarrassed to admit this, but it turned out to be a pin one of the molex connector housing on the power brick had gotten pushed back . It was the molex connector on the upper left of the brick that I believe handles all of the power outputting to the A/R board and some other items.

Should have checked that sooner, but I pushed the pin back into place, and that did the trick.

Game is running again (in my cabinet), and it should be fine when I get a chance later this week to re-install everything in my friend's upright.

Hopefully it will stay that way now!

Jon

 

[Scott C]

Never be ashamed of tracking down and fixing an issue. Everything is a lesson. I had a K6100 years ago that lost green and after checking several things, it occurred to me to check header pins. You guessed it, the green pin backed out.

Scott C.