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Marquardt voltage selector switches in 437B Power Meter

Jared Cabot All Messages By This Member #107879 I have a 437B here sitting on the healing bench that won't turn on, and it turns out the mains voltage selector switches have gone high resistance. The two switches are right angle mount Marquard brand, 4021.4922, but 4021.4920 appear more common and compatible. The problem is, it seems I need to pay exorbitant shipping fees to ship them outside the EU, or purchase 250 of them from Mouser... Short of replacing the switches with wire links, does anyone know of a possible supplier compatible with cheap shipping to Japan, or a suitable substitute part? Or maybe someone has an old bit of gear they can pull some switches from and send them to me for an equivalent transfer of funds? Thanks!
Dave Smith All Messages By This Member #107880 开云体育 I would buy a junker parts unit. ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Jared Cabot via groups.io Sent: Thursday, July 2, 2020 4:20 PM To: [email protected] Subject: [HP-Agilent-Keysight-equipment] Marquardt voltage selector switches in 437B Power Meter ? I have a 437B here sitting on the healing bench that won't turn on, and it turns out the mains voltage selector switches have gone high resistance. The two switches are right angle mount Marquard brand, 4021.4922, but 4021.4920 appear more common and compatible. The problem is, it seems I need to pay exorbitant shipping fees to ship them outside the EU, or purchase 250 of them from Mouser... Short of replacing the switches with wire links, does anyone know of a possible supplier compatible with cheap shipping to Japan, or a suitable substitute part? Or maybe someone has an old bit of gear they can pull some switches from and send them to me for an equivalent transfer of funds? Thanks!
Chuck Harris All Messages By This Member #107884 If they are the typical sort HP used, they need the grease and oxide cleaned and they should work again. They should be open on the ends, hose them down with IPA, and operate the switch a few dozen times, and see if they improve. A little contact cleaner wouldn't hurt. switches that have been left in one position for decades, often won't work in any other position. It's not like they are worn out. -Chuck Harris Jared Cabot via groups.io wrote: toggle quoted message Show quoted text I have a 437B here sitting on the healing bench that won't turn on, and it turns out the mains voltage selector switches have gone high resistance. The two switches are right angle mount Marquard brand, 4021.4922, but 4021.4920 appear more common and compatible. The problem is, it seems I need to pay exorbitant shipping fees to ship them outside the EU, or purchase 250 of them from Mouser... Short of replacing the switches with wire links, does anyone know of a possible supplier compatible with cheap shipping to Japan, or a suitable substitute part? Or maybe someone has an old bit of gear they can pull some switches from and send them to me for an equivalent transfer of funds? Thanks!
Jared Cabot All Messages By This Member #107885 Yeah, that was my next course of action if new ones weren't cheaply and easily available. These ones are all closed up, but the look to be a snap-together construction so some gentle prying will probably have them apart easily enough. A bit of a clean and wipe then a little deoxit should have them all happy again I think. (I use a Hakko flux pen filled with deoxit red to enable me to gently wipe a minimal amount of deoxit on contacts, works really well to prevent floods and drips).
Jared Cabot All Messages By This Member #107892 Well, I had a go at it and got the switches removed without too much of a fight. A good cleanout, some gentle polishing of the contacts and a bit of deoxit has the unit powering up perfectly. :) Now just to get myself a sensor and cable to play with....

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