BOSS HM-2 problem

[Swampy]

Hey Everyone,

I have a boss HM-2 that functions fine under battery power, but is malfunctional when powered with a wall wart.

I'm reading 4.5 volts at node 2 (there should be 9 volts) and -4.5 at node 4 (which should be 0 v as it is connected to ground through D1 / R2 ).

R2 measures fine, and I replaced D1 even though it measured OK just to be certain.

Any thoughts would be well appreciated!

Swamp

[Mark Hammer]

Are you certain that the wallwart is providing 9vDC and not 9VAC?

[cjlectronics]

Is the plug on the wall wart configured for center pin negative like the boss ac adaptors?

[Swampy]

Is the plug on the wall wart configured for center pin negative like the boss ac adaptors?

yes.

Are you certain that the wallwart is providing 9vDC and not 9VAC?

yes.

[Swampy]

Duh. It was a model that needed a twelve volt wallwart.

I did a little mod and it operates of 9v now.

Chur

[Mark Hammer]

An HM-2 that "needs" 12VDC? NOW I'm confused. Was it previously modified to run off 12v, because a stock one assumes 9v?