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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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7th Jul 2017, 12:45 am | #1 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 951
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Hitachi V-212 Oscilloscope in need of service advice
Hi All,
My Hitachi V-212 20MHz Dual Trace 'scope is showing its age and doing some very odd things, im looking for advice on what to check and fix/adjust to give it a bit of an overhaul, I think probably the switches need a clean, and certainly the BNCs need tightening up! But it also does odd things such as the size of the trace getting bigger or smaller in apparent amplitude as the vertical centre position is adjusted? If anyone knows where I can obtain a service manual/alignment guide, i'd also be grateful, Regards Martin
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7th Jul 2017, 1:30 am | #2 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,553
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Re: Hitachi V-212 Oscilloscope in need of service advice
Hello Martin, if no-one can point you to a PDF within a reasonable time scale I believe I have a paper copy of the manual which includes the circuit diagrams. I could pick it apart and copy it for you. We have about eight of these still in day-long use at work and I own one myself as well.
I've recently had to sideline one at work due to failure of the potted HT transformer, but I hung onto it and kept it complete as a potential donor for parts to keep the others going. If you find yourself needing anything (else) for yours, let me know. Mostly a combination of switch cleaning and occasional power supply cap replacement has kept our little fleet going. You will also probably find circular cracks in the solder around the legs of any PCB mounted semis which get warm in normal use. I routinely resolder them if I have the PCBs out for any other reason. |
7th Jul 2017, 1:41 am | #3 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 951
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Re: Hitachi V-212 Oscilloscope in need of service advice
Cheers, well the HT seems to be one thing that is working! Never thought of dry joints but that makes sense.
Managed to find a service manual online, its a bit of a rough scan but mostly readable. The PCB layout diagrams are appalling but the schematics are not too bad! I just hope I have better luck servicing this than im having trying to fix my Marconi 2955B!
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I got food in ma belly and a license for ma telly My Blog - http://g7mrv.blogspot.com |
7th Jul 2017, 8:05 am | #4 |
Nonode
Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
Posts: 2,858
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Re: Hitachi V-212 Oscilloscope in need of service advice
I had one that worked when it wanted. Turned out to be dryjoint on a pcb mount connector pin. Took a bit of waggling of plugs and harness to locate it.
I will look this morning to see if I have any manual copy. Rob
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7th Jul 2017, 9:06 am | #5 |
Nonode
Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
Posts: 2,858
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Re: Hitachi V-212 Oscilloscope in need of service advice
Martin, you are in luck! I have 5x pdf of the manual. I copied and split into parts to email.
pm your email address and I will send them to you. Around 15Mb the 5 in total.
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Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd |
7th Jul 2017, 9:15 am | #6 |
Heptode
Join Date: Jun 2010
Location: Zurich, Switzerland
Posts: 538
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Re: Hitachi V-212 Oscilloscope in need of service advice
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7th Jul 2017, 9:18 am | #7 |
Octode
Join Date: Feb 2007
Location: Ely, Cambridgeshire, UK.
Posts: 1,975
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Re: Hitachi V-212 Oscilloscope in need of service advice
mine has a Dicky on off switch I have to wobble it sometimes , one day I will replace it
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9th Jul 2017, 5:20 am | #8 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 951
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Re: Hitachi V-212 Oscilloscope in need of service advice
Cheers all,
Managed to get the service manual online, so far only had time for a quick visual inspection and a squirt of switch cleaner on the open wafers of the timebase switch. Most of the other rotary switches seem to be sealed/moulded, so not at all sure how to clean those! When Im next free to work on it (annoyingly, gainfull employment keeps getting in the way!) I think i'll take the PCBs out and give the soldering a good going over.
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I got food in ma belly and a license for ma telly My Blog - http://g7mrv.blogspot.com |
12th Jul 2017, 2:37 pm | #9 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 951
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Re: Hitachi V-212 Oscilloscope in need of service advice
Well, ive had it all apart, every switch and pot blasted with Servisol, any joints on the PCB that looked off resoldered, connectors tightened etc etc,
It seems to be happy now
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I got food in ma belly and a license for ma telly My Blog - http://g7mrv.blogspot.com |