Sorry, you cannot (easily) bypass the speed control circuit. Explanation below. I owned four of these. Back in June while I was sanding with one of them, I brushed my arm against the the “anti static” vacuum hose that sends sanding dust to my grounded, metal piped dust collection system and because it was an unusually dry day, I got zapped. I continued working with the remaining three sanders (one for each grit, saves a ton of time by not having to change paper, especially on little “assembly line” jobs) and I got “zapped” a few more times. At the end of the day I tore down the sander, checked the brushes (OK), checked the switch (OK) did a computer search and found that the speed control was prone to failure due to static discharge. Decided to wait for pay-day before ordering a new board. Finally ordered it in early July. Continued sanding with the other three sanders in the meantime. Shipping was delayed due to COVID-19, but finally got notice of shipping via US Mail in late July. Waited and waited for...