2467B... it's all " fixed " !!!
Can't believe it....
Meant to keep it at that for now, and just button it back up. So before doing that I cleaned the cover, pouch, front panel... because it was all sooooo filthy gooey disgusting.
Removed a sticker as well.
Now is so much better and pleasing to look at and play with, like I bought one
In the pouch I found ... a lovely user manual in like new condition, as well as a little accordion style user guide for the 2445/2465/2467 scopes.
AND... a cool little gizmo : a vinyl, foldable Tek blue viewing hood !
Looks so cute. Inside there is a filter to attenuate light reflection for an even better effect.
I gave it a try, works well. The filter is a real improvement as well. I now understand what this red graticule illumination is for.... always found it useless so far... but it's mandatory when using the hood otherwise you just can't see the graticule, at all.
I shoved my camera into the hood, adjusted the ISO setting by trial and error and eventually you can get quite nice piccies of the screen ! Next to zero light reflection, good contrast... everyone should have one of these ! I am so tired of never being able to take a decent shot of my oscilloscopes when I need to post something here... problem solved then.
But my daily driver is my Fluke / Philips combiscope, so I would need to make a custom hood for this scope... I mean in digital mode it can print a screen capture of course, but in analog mode, obviously not...
So, I et the scope dry a bit, then I powered it up to make sure it survived the washing. It did.
I got then got carried away and played with it some more... and heart attack again : the time base problem arose again : turning the TB switch on the front panel would modify the readout on the screen but the signal would remain unchanged on the screen !
Plus, this time... it happened on the MAIN time base, not the delayed one ! If the Main time base is fucked as well, scope is useless !
Then.... light bulb time...I finally put all the clues together and came to a happy end : when I looked at the front panel to see what was the frequency thje probe compensation was outputting... to my amazement it did not say "X3 or "Y"... no, it says " 5Hz to 5MHz " !
What the fuck does that mean !!! Does the CPU at power up, generate a random number to decide what frequency it's going to use today ?!
So... I measured the frequency of the probe calibrator output, using my lovely Metrix Nixie counter. Hell I was not disappointed... the frequency of the compensation signal DOES indeed change as you rotate the Time base knob !
So when you look at the signal with the scope, the signal always looks the same because the scope automatically modifies the frequency of the compensation signal to track the sweep speed ! So overall, it does produce what I was seeing : you change the sweep speed but the freaking signal on the screen does not change !
So that's why I could not always reproduce the problem... it only shows when I look at the compensation signal, but of course works fine when I was later feeding the scope with Philips sign gen !
Now wonder I was starting to lose it...
So then since I have this nice user manual, I rushed to see what it would say... and to my surprise it DOES NOT mention any of this, not a hint !!
I did find mention of it though, but a couple pages further, in a totally unrelated section ! " Timing Check " !
My understanding is that the probe calibration signal is generated using the same time base that's used for the sweep circuitry. So if you want to calibrate the scope time base, instead of feeding the scope with a signal generator and looking at the screen, you can just measure with a counter, like I just did, the frequency the scope puts out on the compensation pin....
So.... in the end I have no time base problem then ?! No fucked up ASIC ?!
Then, the other big problem, the nasty offsets on Ch1 and Ch2 on most ranges.
In the manual I stumbled upon a page about DC balance.... no adjustment / trimmer on the main board no... this freaking scope can adjust the balance/offsets on its own, like the SPC procedure on a digital Tek scope !! Just hit the magic key combination to start the procedure, and the scope balanced both channels in a just a few seconds, reporting no error. Simple as that !
I checked all range on both channels, every single range is SPOT ON, even the sensitive 2 and 5mV / div settings !!
This scope is as good as new, no problems any more, a winner I am telling you !!!
So happy I bought it, a good deal ! This scope is a keeper !!
Obviously all of you out there with a 2465/2467 knew very well all along what my "problems" were, and were laughing in the background instead of rescuing me.
Needless to say, I hate you all deeply !!
I can't believe you let me rot that much for so long. You have no pity, not even for a fellow TEA. I am extremely disappointed.
I feel I need a 6 months TEA abstinence to rethink my membership...