You have to fix the attenuators before you calibrate the scope.

In my case you could hear that one relay wasn't pulling, but I guess you have to know what you're listening for. the attenuator apart - sadly it didn't occur to me to diagnose this by resistance measu

You can diagnose relay contact issues from outside the scope with a DMM. Simply measure the resistance from the center conductor to the shell of each input, as you run through attenuator settings. In

Hmmm, what did you touch the test point with? Tip of the probe? If so, it shouldn't be a problem: Maximum Input Voltage 400 V (DC + peak AC) or 800 V (p-p ac at ≤ 10 kHz). If you touched it with the G

Image links - hopefully these'll work: https://image.noelshack.com/fichiers/2020/02/4/1578575821-r0159787.jpg https://image.noelshack.com/fichiers/2020/02/4/1578575799-capture-2020-01-09-a-13-44-58.jp

Sure, but compared to a 7K series or my 485, there's control lag that you'd be able to notice. Doesn't bother me at all, but I still notice it. No, this is a consequence of how the pots are scanned. T

Beg to differ, this IS normal. Pins 14/15 are the inputs of an opamp in negative feedback. They should both be at zero volts, or very near. What's important is the current into the DAC, which can't be

I have a 2467 with the CTT option, and I like it a lot. It's my goto spelunker scope, though it does feel almost sacrilegious to use an MCP CRT for everyday troubleshooting. I find the controls very i

wrote: Hmmm, you already see the output of the horizontal amplifier - that's what your CRT shows. The only thing is that your horizontal output ( https://youtu.be/8dzxGlcErUo?t=10) is differential. By

wrote: I guess it depends, though a large section of this document ( https://www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf) is about "Front-Panel Diagnosis" which largely interrogates the

Hey Bill, I think it's safe to say that you have more than just a triggering issue, as your OSD (on-screen display) is jumping around as well as the traces (see e.g. around here https://youtu.be/j6Dqk

This <http://w140.com/tekwiki/images/8/87/070-0496-01.pdf> one? wrote:

Did my little bit - thanks for keeping the forum alive and thanks to everyone who contributes here. Happy new year, Siggi wrote:

You may have a bad or flaky input attenuator. Set the scope to DC coupling, and measure the resistance from the inner conductor of the input to the shell. It should be 1MOhm on the dot across all vert

wrote: I like this method - put the scope in X/Y mode and input a sine or triangle wave. Also, if you haven't seen this document before, give it a read: https://www.sphere.bc.ca/test/tek-parts/trouble

You can start by looking at the A-sweep output. Per the service manual “A and B sweep generators each produce, upon receipt of a gate, a negative going sweep of 1.0 V/div of horizontal excursion, star

Hey Reg, I can't speak to these errors, but wonder if you know what you're getting into with the TDS 6XX series. These are CCD-based scopes, meaning they capture in real time at up to 5GS/sec per chan

wrote: On my new-to-me 577 the storage brightness knob only works when the collector supply is turned down as near zero as makes no difference.

the +1.36V and -1.25V references on the A5 board. If those are good, then the DAC and a bunch of supporting machinery is working right. If those are way off, then you're going to have all manner of pr

While you're in there also look at the interrupt generator counter. On my 2467 schematic it's designated U2640 on schematic <1>. This should be generating a regular interrupt every 3.3ms, and there's