Oscilloscope Hitachi V-212 two channels 20MHz 1990 test repair teardown (missing trigger)

wow look at the cosmetic state this scope is it, it looks brand new, but it is from 1990 amazing.. the repair is even more chocking ! i found all errors, fixed it all, i say this scope was NEVER working at all !! they forgot to mount a bridge wire on the pcb for trigger !! and my scope is not the only one with exactly this fault, see comments.

#repair
#oscilloscope
#teardown

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I use auto generated subs, so if you find errors worth fixing, please comment with the time in the video you saw the error, i will be happy to fix it. This also apply to the Danish version.
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[jonathantouboul]

Incredible, I just got a well-loved v-252 from a retiring science lab, I tested it and found no trigger, watched you video and spotted the SAME jumper missing, although it's a different scope and a different chip brand... I soldered a jumper in place and my trigger now works nicely! Thank you for documenting this, very helpful, saved me a headache!

[gcpete]

I just bought a used V212 for repair. dated June 1993, and sure enough that one was missing the jumper for the IC ground. new at this, so likely would not have notice it without your video. Thank you Thomas!

[walliesdebeer]

I am in South Africa and also bought one of these brand new triggerless 30 year old scopes secondhand for the equivalent of 20 Euros. Guess what? no jumper is installed. I'm going to fix it tomorrow. You are my hero Thomas!

[HenryPlumb]

I've just acquired one off eBay from a working lab somewhere, scope working but no trigger, exactly the same jumper missing. Amazing so many of these seem to have been shipped with no working trigger and have lasted decades like that!

[smilleur]

I just found two vc-6015s in a god damned dumpster at the college i work at and THEY LOOK BAND NEW IM SO EXCITED

[danielito]

when in low frequency mode and only when not measuring anything, my V-212's waveform is dotted, what could I do to fix this?

[robertdeptula]

Reporting missing jumper from Montreal, Canada. Problem fixed. Thank you! You would expect "high touch" from Hitachi, but nooo...

[michaellundsrensen]

I bought such a scoop in 1980 and it worked fine then. I've had it sitting in the box since about 1990, so I wonder if it still works?
Are there any capacitors that have become old, tired and leaking or can I expect it to work?

[alphaducentaur]

I found one in the dumpster at my college, so I took it home. It has the same missing jumper (though in my case, it's a bit different because the electrolytic capacitor under the chip is connected where the jumper is supposed to be). Thank you for saving me time 😄!
I may have a stupid question, but this is my first oscilloscope repair, how am I supposed to remove the knobs (the ones that don’t have screws)?

[tsjwang]

Same thing happened to me! I bought a used scope from ebay, working but no trigger. same missing jumper. this fix worked.
there must have been some bad work instructions and lack of testing that led to a bunch of defective scopes being shipped

[ebswift]

I just scored the same model Hitachi V-212 today, not yet powered on until I check it over, but the first thing I've discovered is the same missing bridge wire as others have also mentioned.

[Animatronicsu]

I just bought an used Hitachi v-212, the trigger doesn't work so I looked inside, and guess what, jumper missing ... Thanks you so much for letting us know the solution

[walmirbraga]

Eu tenho um dessa marca e modelo, e o trigger também não funciona, porem funcionava, vou ver se consigo com essas dicas faze- lo voltar a funcionar!!
Thanks for shared!!
Braga
PY 4 PCJ

[beakytwitch]

I think the Y driver transistors by design are somewhat overdriven, the better to push the bandwidth up. The CRT is single channel, and the "double beam" comes from chop and alt switching, and for that reason on its own we want high bandwidth.

[omarcusihuaman]

Its really hard to believe that jumper was missing 😱. I got a similar HItachi last week, it turns on but theres no signal.

[ryan]

is this model pretty ok for a beginner ? its going to be for audio amps

[turkalpkucur]

I think it is a good oscilloscope for beginners! thanks !

[juniorcomsono]

Hey thomas! What's the name of that tool you used to figure out the Diode and its values?

[ebayscopeman]

One place I worked had dozens of these. They used them for years. Never saw one fail in 10 years. Yours must have been built on a Monday. Maybe they were just using it as a X-Y scope where trigger was not needed and the vertical failure is why you have it.
Sam
W3OHM

[mattfisher]

I wonder why a scope that never worked had a burnt transistor 🤔