repair dim CRO trace

[djacobow]

I have an old 20 MHz Goldstar CRO (OS9020-G) that I actually bought new in high school. I used it through college, but hadn't taken it out of storage until EEvblog got me back into electronics.

It seems to work just fine except for the trace is very dim, even with the brightness turned up all the way.

Anyone have some hints on where to look first to fix this guy up? I don't have schematics, sadly.

I'd like to get it going again because, if nothing else, it works much better for lissajous patterns than does my Rigol DSO.

[Andy Watson]

Is this info useful:
http://www.eserviceinfo.com/downloadsm/43481/LG%20Goldstar_9020.html
Looks like the same beast!

Edit: Oh hum! I thought I'd linked to the "home page" for that model, but it appears to be a direct link for the download. You'll be wanting the other two parts:
http://www.eserviceinfo.com/downloadsm/43482/LG%20Goldstar_9020.html
http://www.eserviceinfo.com/downloadsm/43483/LG%20Goldstar_9020.html

Or go to the eserviceinfo home page and search for the model number.

[JOERGG]

Or here, Google is your friend

http://www2.produktinfo.conrad.de/datenblaetter/125000-149999/130079-sp-01-en-Oszilloskop_OS5020.pdf

[djacobow]

Andy, that's it!