EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: flynwill on May 12, 2015, 12:01:39 am
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The power switch on my 2465 suffered an ohmic failure a few weeks back (and from the amount of smell I expect far more damage than just a cooked switch).
I finally got around to the repair and thought I would post because I know there is at least one other forum member out there with the same failed switch. (And this switch is probably common to a lot of Tektronix scopes of the era).
The original is by ITT/Shadow (do they still exist?) but it turns out that this part is still being made. The replacement is C&K part number "NE18 2U EE P 6AMP" and is available at Mouser http://www.mouser.com/Search/ProductDetail.aspx?R=NE18_2U_EE_P_6AMPvirtualkey61110000virtualkey611-NE182UEEP6AMP (http://www.mouser.com/Search/ProductDetail.aspx?R=NE18_2U_EE_P_6AMPvirtualkey61110000virtualkey611-NE182UEEP6AMP)
If you try to compare that part number to the coding listed in the published spec sheet however it doesn't make any sense. It took a bit of guesswork to get the right thing. I presume that C&K is in the process of changing the part number system for these parts and hasn't gotten the datasheet updated yet.
In any case the new part is a perfect match (except for the nice pretty green color instead of black). The little plastic cover that Tektronix had put over the old part to protect service personnel from the exposed leads on the top of the old switch fits. But it isn't needed since the new part does not have the exposed metal there.
Of course while I have it open I noticed a pair of dodgy looking capacitors, one clearly starting to leak and the other with a bulging top. They are the line filters for the +/- 15 V supplies. They were listed as 180 uF -10/+100% so I decided to replace with 220 uF +/- 20%. (do they still sell caps with that sort of specification any more? It used to be common.)
Hope this is helpful.