a replacement board. The more I see after that the bigger the payoff.
Someties it works that way. In the 70's I repaired some CB radios for the locals. Did not charge much as I was partly doing it as a hobby and building my skills as I had a regular job. I remember one that a dealer brought to me that I had not worked on before. Took several hours to repair the problem There was a verticl circuit board that was hard to run checks on. I finally saw where one of the leads was not soldered. The dealer brought me 5 or 6 more later, and it only took a short time to find some leads within an inch of the same place that was not soldered.
Many items will have one or two problems that if you check those first it will repair 99% of the problems.