Leader LBO-520 Dual Trace Oscilloscope issues

[YoshiKnuuckles]

I recently obtained this old scope and I'm having issues with it. Instead of trying to explain it, I decided to take a video of it's ailment.

https://youtu.be/GypDtO2W9rE

I should probably give some background about myself, and the scope. I'm currently a first-year EET student who is attempting to set up a lab at home to supplement my college studies. This scope was something I picked up in a lot with some other old electronics, and it was basically free. I'm trying to troubleshoot what's wrong with it, but I have no clue where to start with this thing! Would be awesome to get it working properly again, I was hoping to use it as a learning starter scope.

Any help or guidance with this is appreciated. I should be capable of doing the rework on the unit myself. However, I need help determining what needs replaced, or if the unit is beyond economical repair (I doubt this is the case.)

[tautech]

Welcome to the forum.

I've not watched your vid yet but a helpful pdf on CRO troubleshooting can be found in the Repair Links thread at the top of this board.

[oldway]

What about channel B ?
Does it work well or does it have the same problem as channal A ?

[YoshiKnuuckles]

Channel B shows almost all the same symptoms as Channel A. Both channels seem to function as they should, the only real issue with the scope is what I've shown.

I looked over the CRO troubleshooting guide, and I'm having a bit of trouble figuring out where to start. A lot of helpful information in there though.