Oscilloscope for beginner question

[Arcade-Projects]

I recently got a few dead boards for free, there's a 1 lost MVS board, a Tekken 3 a Kaneko board and a few others. Some turn on, some don't give any sign of life.

I know near to nothing about PCB repairs, but I definitely want to learn. I'm a programmer so I'm comfortable with logic, math, epproms, and a few other concepts, but I never repair anything electronic related.

I stumbled upon a somewhat cheap oscilloscope but I'm not at the point of deciding whether it is a good scope or not yet. It is a dual channel, 20 Mhz scope.

Is 20 Mhz enough for learning to troubleshoot PCBs? I've read 50 Mhz is better, 100 Mhz even more so. What is considered the minimum spec?

Here is the manual if you want to take a look.

1drv.ms/b/s!ApWphfoykW4hlWQvVQoljYHR6nJI

Thanks!

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