MISC: Technics SH-3433 Scope

[Q-Eight]

If a fella had some money, he'd make you an offer. Mine works, but has some serious burn-in on the scope. Replacement scope tubes are non-existent.

 

[Doug G.]

If a fella had some money, he'd make you an offer. Mine works, but has some serious burn-in on the scope. Replacement scope tubes are non-existent.

Offer him a buck-two-eighty or trade that Gremlin.



Doug

 

[Q-Eight]

Offer him a buck-two-eighty or trade that Gremlin.



Doug

I'm so broke right now. Haven't worked in almost 2 years and I've burned up all the gov't handouts.
I suppose I could apply for Welfare....

 

[gene_stl]

Jon how much would you sell it on QQ for??

 

[MidiMagic]

Well, mine doesn't work. It lights up, I can focus the beam, but it shows a waveform when nothing is coming in (no straight line) and when there is audio coming in, it doesn't change much.

I just checked eBay and the last one sold for almost $800 and it didn't work, so I am going to put this one on eBay and take a shot that someone who knows what they're doing can fix it. It looks very clean. It might just need some caps swapped or something. I am not up for it at this point.

Oh well.............

Sounds like the power supply needs new capacitors.

 

[Doug G.]

Sounds like the power supply needs new capacitors.

Could be. I was going to say it sounds obviously like the deflection circuits aren't working and probably due to operating voltages being absent. None of them working points to the power supply.

Beam circuits OK. You can see the four identical deflection circuits in the one photo. Not too complex - compared to a television, anyway.

Doug

 

[MidiMagic]

If excessive ripple in the power supply (from failing capacitors) gets in the deflection circuits, it distorts the waveforms they produce.

This reminds me of a typo in a homework handout in my college digital electronics class:
"Observe the oscilloscope and draw the waveworms on the blank graph at right."

The problem with repairing an oscilloscope is that you need another oscilloscope.