Sorry to hear that! What's the battery voltage reading on the ToneWoodAmp when you do get it to power up? It should display at power up.
Make sure you're changing all three batteries. If one is stuck and only two are being changed, you'll experience intermittent power issues. If the third does happen to be stuck, loosen the screws on the bottom of the TWA near the battery cover about a quarter turn. Let me know if this helps!
Hi, I recently started trying to use my TWA after it sat on a shelf for 2 years. I replaced the batteries, updated the firmware, but no effects coming out of the sound hole. I also purchased a fishman pickup bundle, I have a question, does the pickup have a battery as well?
It might be worth checking for corrosion on the internal tabs. If you notice the sound is cutting in and out I would try swapping the cable out for a new one.