Any repair-saavy types out there?

Does the LED light?

 

Are you using a battery or an AC adapter? If an adapter, is it 9VDC or 12 VDC, and is it regulated?

 

Use the voltage indicated - if that's 9, don't run 12+ volts through it. Chances are that a bit of overvoltage won't hurt it, but every device has its own melt-down point based on the components in it and their individual tolerance to overvoltage.

 

Bear in mind that Boss "ACA" prior to the mid-90's was 12VDC, and was later changed to 9VDC. So older Boss ACA pedals actually work best with a 12V adapter.

 

I found this on the Boss site, regarding the differences b/w their PSA-120 (current) and the ACA-120:

 

I have a BF-2 that uses a ACA voltage. I used a 9 volt adapter that worked fine. Some ACA pedals work ok with 9 volt some don't.

 

My guess, since the ACA-120's voltage drops with load increases, is that it puts out probably 10-11vDC, because some pedals produce a higher current load on the power supply.

 

Again, the ACA specs changed in the 90's. An ACA pedal from before that change will operate best on 12VDC, and ACA from after the change will require 9VDC. The original ACA had a resistor after the power supply input which takes the voltage down from 12 to 9, in addition to the fact that it's unregulated. So an older ACA pedal can be easily modded for use with a modern ACA (or even PSA/Onespot/etc.) supply by replacing that resistor with a jumper wire.

 

Bongomania makes a good point about changes in the device over time.

It also makes me contemplate my earlier comments.

Also, although significant overvoltage can be a problem, when it comes to 9V devices, power supplies are inconsistent at best. Most of them provide at least 10V so that when they're under load they won't sag below 9. Some will test out considerably higher - even 13 to 14 volts - with a digital voltmeter when there is no load. This is fresh in my mind because I was testing wall warts last weekend to come up with a backup that's compatible with my Warwick Rockbag pedalboard. (I save all the wall warts from old devices so I have a go-to resource if one fails...DC power tips are easy to change.) I was surprised to see how many power supplies labeled as 9V actually tested as producing 13+ volts when under no load. It shouldn't necessarily scare you if a 9V wall wart tests higher when there's no load on it.

It's also worth mentioning that wall warts are cheapcheapcheapcheap and also inexpensively made. They stamp those things out like chiclets, and the quality control is pretty inconsistent. If we knew the actual range of voltages going through those foot pedals it'd probably scare us.