So I got a Tyler 20/20 in a trade. It sounds good, but when the volume is turned up I get motorboating. I called the manufacturer, who said motorboating is usually a ground issue or a filter cap issue. They offered to fix the issue at no charge if I sent the chassis to them. So I said, oh let me look around and see if I can fix it. I'll send it in if I can't find the issue easily. They told me to reflow the joints first because the F&T caps usually don't go bad. I reflowed some of the joints, marked in photo with yellow squares. That didn't fix it. So I looked on the internet and found out that to figure out which filter cap is causing the issue just take alligator clips and another cap and basically put it in parallel with each filter cap one by one. When the issue goes away that is the cap that needs replacing. So I did this and found that when I clipped the cap across the highlighted cap the issue went away. So I set out to replace that filter cap. Well after replacing that cap the motorboating didn't go away. I tested the cap once removed and it tested fine. Disappointing. Are there certain steps in a certain order I need to follow to find the real cause of this issue?