Boss HM-2; AC power problem

[thuss73]

I was about to sell this and found it wasn't working correctly.

It works fine with a battery but adapter power doesn't work.

A few things I checked already were the adapter jack, D1,D2 and R5 & R6 that divide the 9v. All those checked out OK (Mine is a correct and working adapter.)

I found 4.5v on the ground with the AC adapter and a plug in the input, so I swapped C25 because I thought it was passing the 4.5v to ground, but that wasn't it. Then I ran out of time for troubleshooting for the day. Any ideas where to look next?

[thuss73]

I guess this might explain my problem. I never used it outside a daisy chain before:

Boss ACA & PSA

[thuss73]

And this guy:

http://music-electronics-forum.com/t22873/

I'll assume his mod was to remove/jumper D1 and R2?

[Jazz P Bass]

Which certainly does beg the question: "which adapter do you have?"
12Vdc or 9Vdc?
Center pin negative.
It cannot be Vac!

[thuss73]

9vdc center pin didn't work. I didn't have a 12vdc to test it but it worked in the daisy chain with 9v just like Andreas explains. I removed D1/R2 and it will now accecpt an isolated 9vdc in the adapter jack.

I'm quite shocked this ACA/PSA Boss thing has never come up for me before, I feel quite foolish now.