CurtPalme.com Home Theater Forum

[Curt Palme]

So I bought a Digitech Vocaliser on eBay the other week to play around with. A very cool little box, it will pitch correct, and I bought it for the 4 part harmonizing functions that you can play on a keyboard, and you too can sound like Queen.

Anyways, the seller emails me and says that the unit is rebooting continually, so I told him to send it anyways. Sure enough, I get it, it boots up, and starts working (albeit with a memory error message), but will reboot and lock up at random.

So I change the dead 3 volt lithium battery, and that cures the memory problem, but not the rebooting. I check the +/- 5 volt supplies, derived from a wall wart power supply.

I find that if I take off the front display PC board, the problem goes away, the power supplies are solid. So now I figure something is loading down the power supply (the light behind the display probably), which causes the power supply to fail.

THe -5 volts jumps around every time the unit reboots, and they are the cheap regulators that are running red hot, no heat sink compound between the heatsink and the regulator. So I figure that's it. Change the regulator, add heat sink compound, put it together... still reboots.

Now I'm pissed, but I'm determined to repair it.

So this morning I decide for the heck of it to change the 1N4001 diodes that supply power to the whole unit. Problem solved.

I guess the diode was breaking down for the negative 5 volts, but then recovers, and the unit keeps working.

In my 30+ years of repairing stuff, I've never had an intermittent diode. They either short (most common) or open (rarely).

Just thought I'd share.

[Curt Palme]

So I bought a Digitech Vocaliser on eBay the other week to play around with. A very cool little box, it will pitch correct, and I bought it for the 4 part harmonizing functions that you can play on a keyboard, and you too can sound like Queen.

Anyways, the seller emails me and says that the unit is rebooting continually, so I told him to send it anyways. Sure enough, I get it, it boots up, and starts working (albeit with a memory error message), but will reboot and lock up at random.

So I change the dead 3 volt lithium battery, and that cures the memory problem, but not the rebooting. I check the +/- 5 volt supplies, derived from a wall wart power supply.

I find that if I take off the front display PC board, the problem goes away, the power supplies are solid. So now I figure something is loading down the power supply (the light behind the display probably), which causes the power supply to fail.

THe -5 volts jumps around every time the unit reboots, and they are the cheap regulators that are running red hot, no heat sink compound between the heatsink and the regulator. So I figure that's it. Change the regulator, add heat sink compound, put it together... still reboots.

Now I'm pissed, but I'm determined to repair it.

So this morning I decide for the heck of it to change the 1N4001 diodes that supply power to the whole unit. Problem solved.

I guess the diode was breaking down for the negative 5 volts, but then recovers, and the unit keeps working.

In my 30+ years of repairing stuff, I've never had an intermittent diode. They either short (most common) or open (rarely).

Just thought I'd share.

[macgyver655]