1972 Dual Trace Dumont 2100 Oscilloscope Schematic/Manual

[TexRedNk]

Howdy all oldtimers!!
I have a model Dumont 2100 Oscilloscope where one of the traces is "off screen" and the vertical balance control will not bring it back up. This ia a vintage 'scope that works to 10 Mhz which serves most of my needs. I am looking for a schematic or the service manual in PDF format.
There is one of these 'scopes for sale on eBay. Seller is # 114586205170 and you can find a great
picture of the controls. I have searched many sites and have come up empty. Any suggestions are greatly appreciated.
73s, Doug

 

[PETERDECO]

Hi Doug. May I suggest that you clean all switches and controls with contact cleaner before doing anything. Not just the ones on the front panel but any internal trimmer pots too. Use a pencil to mark their position, spray and turn them back and forth a few times.

 

[TexRedNk]

Good Idea PETRDECO ! Problem is one trace is off screen and even with the 'Locator' putton pressed, it still will not come on screen. I know it is just a biasing problem and if I had a shcematic, I could check voltages and resistor values. Stil waiting for documentation on this vintage model.

 

[JJ74]

Good Idea PETRDECO ! Problem is one trace is off screen and even with the 'Locator' putton pressed, it still will not come on screen. I know it is just a biasing problem and if I had a shcematic, I could check voltages and resistor values. Stil waiting for documentation on this vintage model.

Hello
I recently acquired the same scope. I’ve searched everywhere for a service manual, No Luck.
Mine has a lot of interference on channel one. Channel two is flat. I was thinking on checking the capacitors. Before I Open it, I would really love something to look at. This is my first ever scope. I figured if I’m working with old equipment I better have manuals. if you have had any luck finding documentation, I would appreciate info, even if it cost a little. All information IS valuable.