Products > Test Equipment
Teardown - Hitachi V1065
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old gregg:
Seems that the switches end up with issues. I've a Hitachi VC-6023 and its push/pull buttons are a gamble everytime I want to use one. I can't pull the button otherwise it doesn't go back to its orginal position, which give an odd reading.

I thought about changing the part (but not references) but maybe a good cleaning could do the trick.
rbm:

--- Quote from: true on March 02, 2014, 09:51:45 pm ---MINE HAVE THAT CHIP TOO :( Only on the right side. Wonder why that is.

--- End quote ---
I've got a theory for this.  Mine also have both top corners chipped.  When I took my scope apart for servicing, I noted that the metal cover is captured by the bezel along the top edge and the two sides.  It needs to be slid into place carefully when removing and replacing.

I think if a ham-fisted service tech just slams the cover into place without being gentle with the corners, the corners get chipped.  Afterall its hard metal versus soft plastic.  Obvious which wins out.
rbm:
My V695 scope has exactly the same problem as anjimoo posted above.  The selector switch is truly broken on the inside and does not function as it should.  It should have a centre resting position with momentary action either up or down.  Unfortunately, mine stays fully up or fully down and has no centre detent.

I've been doing some research to find a replacement.  Here is what I have found out so far.

The original switch is a Fujisoku ALE2S-2M4-10-Z , DPDT paddle switch with the function (ON)-OFF-(ON).  The technical data sheet for the switch can be found at:
http://copal-electronics.info/en/00134/01b64.pdf

Fujisoku was purchased by Nidec Copal Electronics in 2007 and Copal continues to build the switch.  I contacted the Canadian representative for Copal to ask about the availability of this switch.  I heard back that the switch is available through Digikey via the Copal part number above.  It is not listed on the digikey web site nor is the part number searchable.  The downside is that the minimum order  is 50 units (since the factory has to tool-up to make the switch).

Doing more research on Digikey and Newark Electronics web sites, I discovered a very good substitute for the OEM switch.  This is a NKK Switch, part number A28KB-BH-ND.  This switch has the following characteristics:  DPDT, function (ON)-OFF-(ON), snap for paddles, straight with bracket, Grey 14mm paddle X 4mm wide. The paddle is slightly narrower than the Fujisoku, as shown in the drawing below:

However, any space in the switch opening can be taken up by making a flexible sheet to fit tightly up around the handle, and slide up between the front panel and the scope case.  This switch is not stocked at Digikey or Newark. 

I placed an order with Digikey for the switch.  It was an extraordinarily long lead time to get the switch but it finally arrived.

I proceeded to remove the Horizontal control card as described in the first post of this thread.  Once removed, I desoldered the Fujisoku from the card. It was difficult to do. The reason was that the switch has a metal band that is also soldered to the board in addition to the pins.  There was a risk of damaging the board so to ease the risk to the PCB, I clipped the four tabs that fixed the metal band to the board.  I used a solder sucker to disassemble the solder joints and loosen the switch.  Once free of the board, I proceeded to clean up the pads.  I did lift a couple pads because I don't have the proper desoldering equipment; it would be best to use a desoldering station but I didn't have access to one.


You can see the switches compared side by side below.  The NKK obviously has a smaller paddle.  What is also different between the two switches is the action; the NKK is much softer in its action than the Fujisoku.  I think this softness will give the switch a longer service life.



I double checked the contact action on the NKK versus the schematic and verified the orientation of the switch.



I placed it on the board, soldered up and refitted the PCB back into the scope.  The paddle fit through the opening with no problems and doesn't look too bad.  Operation is perfect and the full functionality of the scope restored.



This is a viable, easy fix for those with a broken Hitachi scope.
anjimoo:
Thanks Robert! Your research is most appreciated. Looking forward to hear if this component is a proper substitute. My scope is usually gathering dust b/c of the switch. Hopefully this'll revive its use :)
Rmcka4004:
 :-BROKEi think I've found a replacement sw at digikey. I ordered it today and will share if it works
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