Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Oscilloscope repair help needed

Status
Not open for further replies.

hadihf

New Member
Hi,

I have an old Trio Oscilloscope type CS-1022. It has a problem that the trace is very bright. I cannot reduce it with intensity control. If I rotate the intensity clockwise I hear a high frequency pitch. Any help will be greatly appreciated. Also can somebody has a schematic/service manual?


Regards
 
The high frequency noise is probably the high voltage supply complaining about the load. Check the resistors in the CRT circuit, the bias is off. Most likely one of the resistors has gone open, should be easy to find.
 
Hi generally you find a series resistor to intensity control. it might have opened up-- check and replace.
 
Scope Repair

Thanks for all your help.

I got a service manual ...the intensity control center viper (red arrow) does not have series resistance?

Regards
 

Attachments

  • HV.pdf
    118.9 KB · Views: 1,463
hadihf said:
Thanks for all your help.

I got a service manual ...the intensity control center viper (red arrow) does not have series resistance?

Regards

What intensity control? I can't see it next to the red arrow :confused:
 
scope repair

This is just part of schematic showing HV portion. The intensity control (10k)has one end to +5v and other to ground. the center is marked with arrow going to the transistor pair. Anyway now that i purchased the schematic I am confident to repair it. I will post the results.

Thanks
 
hadihf said:
This is just part of schematic showing HV portion. The intensity control (10k)has one end to +5v and other to ground. the center is marked with arrow going to the transistor pair. Anyway now that i purchased the schematic I am confident to repair it. I will post the results.

Thanks

Ah.... that makes more sense now :)
 
What a complicated circuit just to make 2000V.
My old 'scope has a high voltage winding on its power transformer.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top