ZapPulse 2.1 HELP!!!!

[Schaef]

HELP!!! I purchased a ZapPulse board a while ago, and finally got around to wiring things up, and think I may have done something really bad! When I first wired it up, it didn't seem to be doing anything. So I changed where the ground wires were, as I figured it was oscilating or something. Here's a picture of what the current wiring looks like:



(Ignore the uglyness for now) What you're looking at is the board mounted to the side panel, earth attached to the chassis, and the bolt floating in the air is the ground point. What happened when I turned the amp on is, the magic smoke started to escape within a second of power on. I immediately shut it off, and now need HELP!!!

What's wrong in the picture? The ground from the amp board, the caps ground references, and two of the legs of the transformer are all tied at the bolt, with the bolt floating. When I first wired it, the two transformer legs were tied together, then a third wire ran to a single spot on the chassis where it was met with a wire from the ground of the amp board and the two capacitors. It didn't smoke in the other configuration, why did it smoke now?

I'm also wondering, is the amp board now dead? Is there an easy way I can check it? I have a cheapie volt meter and a 100MHz scope I can check things with, but I'm a bit of a novice at the scope, so any help is appreciated!

I'm afraid to turn it on now!

Here's a couple of additional pictures if it helps...

[peranders]

Have you checked the power supply voltage BEFORE you connected the ZAP pcb?

[Lars Clausen]

How did you connect the single bridge rectifier with the 2 fourpole capacitors?

Can you draw up a wiring schematic and post here please?

[Schaef]

Originally posted by peranders
Have you checked the power supply voltage BEFORE you connected the ZAP pcb?

Well, I checked it before the re-wire and everything looked fine. The voltage was where I expected it, and what not...

Originally posted by Lars Clausen
How did you connect the single bridge rectifier with the 2 fourpole capacitors?

Can you draw up a wiring schematic and post here please?

The other two connectors are marked N.C. (assuming not connected) they're 10,000 mfd from ApexJr, as well as the transformer which is a dual primary.

I don't have decent software to draw a scematic, but basically, I took the two outer connections on the transformer and tied them to the bridge. The '+' of the bridge is then tied to the '+' of one capacitor, with its '-' tied to the bolt. The '-' of the bridge is tied to the '-' terminal of the other capacitor, with its '+' tied to the bolt.

The two center connectors on the transformer are also tied to the bolt. (which also ties the two secondaries together)

The '+' of the amp board is tied to the '+' side of the '+' capacitor, the '-' of the amp board is tied to the '-' of the '-' capacitor. The ground of the board is tied to the bolt.

The bolt, is then floating in the air.

I hope all of this makes sense. Also, Lars, do you think I've toasted my board, or is there a chance its still good? (It was a small amount of smoke for less than a second)

Thanks for the help guys!

[Schaef]

Okay, I played around with some cad programs I have and came up with the following wiring diagram:


Keep in mind, this is how the wires actually go... not an attempt at a schematic.

Hopefully this will help clarify things as well!!

Thanks for helping!

[Schaef]

Anyone with some more help?

[Richard C]

You really need to speak to Lars about this.

Your psu appears to be electrically correct but the layout is not good.

If your amp smoked it's extremely unlikely it will work correctly again without repair.

[Lars Clausen]

Dear Robert

We have a full warranty programme for this type of problems. And we will also cover you with this.

However we need to find the cause of the problem first, if not, the new module we send you will 100% sure also burn,
because if no problem is found, it will still be there.

Can you establish where the smoke came from, are there any burnt parts on the module or elsewhere?

If you disconnect the module, what voltages do you measure on + and - with respect to GND.

Lastly: you should NOT use the bolt as a star GND. It is bad practice, and will cause your amplifier to hum when you
connect loudspeakers. Follow the drawing in the cookbook, it will give perfect results.

Best regards

Lars Clausen