Help Needed: Circa '83 Boss DM-2 works with PS but not a battery

[eurekaiv]

Anyone seen this problem with an older Boss pedal before?  The pedal works beautifully when powered with the correct supply but on battery power its not passing signal or lighting the LED at all.  Seems like the obvious thing is a bad clip but I opened it up and I'm getting power to the board just fine so the pedal is powering up but it's not actually "turning on" for some reason.  It appears to have the battery wired exactly like I would expect—with the power supply input jack shorting out the battery when the barrel jack is inserted. I'm stumped here and would love some help.  

[Processaurus]

Bad DC jack, or bad wiring of the ground to the input jack (assuming it uses the stereo jack trick to connect battery ground to circuit ground).  Or bad clip.  Or dead battery from circa 1983 .

[trjones1]

I had a similar problem with an old Ibanez pedal.  I had all the same symptoms as you (works with power jack, not battery; positive voltage readings, etc.).  It turned out that the board itself was cracked around where the power jack was, so some places on the board were getting power and others weren't and it only worked when the power plug was pushing on the board in a certain manner.

I'd check to see if there are cracks on the pcb.  I ended up running wires on the underside of the board directly from the jack to the points on the board which needed power and it works fine now.

[eurekaiv]

I fiddled with it some more and realized what was happening was that it was actually working ok when I turned it upside down and then would go wonky when I turned it back up to see if the light was coming on. How long it took me to sort that out is embarrassing really.  The pedal itself is practically mint and the PCB looks flawless so I think it must be a loose wire or bad solder joint or I suppose maybe the jack could be hosed.