Philips pm 3055 front panel button stuck.

[DoorVb]

Recently I picked up a Philips pm 3055 for free, it was working but the volts per devision on channel A couldn't go lower then 0.1. I figured that wouln'd be a giant problem as I can use channel B. 
Channel B was working fine until a button got stuck (The one in the red circle is broken and the one in the blue circle appears to be working but I can't say for sure). Now the oscilloscope is stuck beacuse of this one button.

Any help would be appreciated.

[Shock]

Service manual is here
http://www.qsl.net/vk5bar/AHARS-Resources/Philips%20PM3055/PM3055%20Service%20Manual.pdf

Here is a similar logic problem. Once you fix the button you can do comparisons between channel A and B but you can only go so far without needing another oscilloscope to aid in troubleshooting.
https://www.eevblog.com/forum/testgear/pm3055-phillips-scope-1x10x-problem-on-channel-a/

In the service manual chapter 10-3 covers the front panel controls. That pcb is static sensitive, also the shafts of the pots are plastic and fragile as well, I can see you already have a broken one.

If it's a stuck button you can try cleaning it on the pcb with iso alcohol, remove it and perform micro surgery (if you can get it open) or rob one from elsewhere e.g. Channel A. It's also possible to retrofit similar buttons but pretty pointless unless you are attempting to repair channel A.

Either way unless it comes unstuck you will need to dismantle the oscilloscope.

[george.b]

Removing the front panel isn't difficult. If memory serves me right, it is held in place by two screws on the back of the panel, on the inside. They should be accessible by just removing the top cover.