Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Diagnostic & Test Equipment

We appreciate your help

in keeping this site going.
 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #1  
Old 12-29-2017, 11:02 PM
MadMan's Avatar
MadMan MadMan is offline
The Resident Brony
 
Join Date: Oct 2016
Location: Chicago
Posts: 1,217
B&K 1460 O-scope troubles

This is my go-to scope for all my actual work-related needs. It's a good runner but I'm afraid it's starting to have troubles. While monitoring a serial data stream on a Cadillac with communication issues, everything was fine, and the data 'on's or '1's were about 1 grid unit high. I left it on for about 10 or 15 minutes (the car and the scope) and when I came back, it was about 1/2 a grid unit high.

I'd never seen this on data before, but I have seen this several times on crank sensor signals - in fact, I've watched analog crank sensors lose their height (voltage) on the scope slowly until the car shuts off from lack of input. Nice way to confirm a bad crank sensor. So for a while I was fairly certain the scope was doing its job.

What I did this time was, I left the car on so the data kept on streaming, and turned the scope off for 15 minutes, then turned it on and sure enough, 1 grid unit high.

I'm eyeing the electrolytics. They're made by 'Elna' but none are visibly swollen or anything. There's also a very large square metal high voltage can capacitor near the power supply, made by Nichicon. I can't find a manufacture date but I'd venture it's in the 70s somewhere.

TLDR: My scope is partially losing it's vertical... amplification or deflection or something like that, when it warms up. What do?
Attached Images
File Type: jpg bk_oscope1.jpg (89.5 KB, 23 views)
File Type: jpg bk_oscope2.jpg (79.7 KB, 20 views)
File Type: jpg bk_oscope3.jpg (109.3 KB, 19 views)
Reply With Quote
 


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:31 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.