I've used many kinds of 9v batteries with the same result, if it's a fishman preamp problem, which accessory should I replace.

This is the internal diagram，When the battery dies, the guitar will no longer sound.

Yes, the battery drains very quickly and doesn't drain when not in use.

I used a 9V alkaline battery, but it also drained very quickly, don't know why.

Made in 1995, I use a carbon dry cell.
Thank you for your reply.

1. The spring has 3 grooves, and they have different differences. Which position is it set in the factory? 2. The 9V battery consumes power quickly and will run out in a day or two, which 9V battery should I use? 3.When the balance is reached, the sound is not clear when the string is pushed at 2 st...