Boss TU-2 Tuner Works With Adapter, Not With Battery

[Ptron]

I have a freind's Boss TU-2 Stompbox tuner that seems to work fine with an adapter but not with a battery. I've tried a couple batteries. I checked the battery clip and input jack. With only a battery and a cable plugged in I do read 9.3V on the PCB but the displays are dead. When he first gave it to me to look at it was faintly flashing "0" a few times then going dead when a cable was plugged in. Now it doesn't do anything. I know that these things have quite an appitite for current by my own TU-2 runs fine on a battery for a long time.

[Johan]

there is a break funktion in the adapter jack. perhaps it isnt closing when the plug is pulled?.
J

[Ptron]

Ooh, excellent call. There are two power jacks on the tuner so there are two breakers in series. I was measuring at the first one which works but the second one is not closing. Thanks much!