[volt-nuts] HP419A Meter Pegged to Right

Chuck Harris cfharris at erols.com
Wed Nov 12 00:17:13 EST 2014

There are certain things that must be done/considered before
washing old electronics:

1) remember there is lots of lead that might not be wanted in
    your dishwasher.  If you choose to use the DW, buy a lead
    test pen for afterwards.
2) tek always suggested removing the paper insulator tubes from
    the old FP style of can electrolytic cap prior to washing.
3) a large cardbord box, with a 60W incandescent light bulb, and
    a muffin fan makes a dandy convection oven for drying washed
    electronics.  There should be a couple of holes in the box
    to allow moisture to vent out, and fresh air in.
4) electronics can't tell when you get it too hot, unlike your
    head, be careful with the hair dryer.  It can easily get
    parts hot enough to damage them.
5) power transformers don't like being exposed to water and
    especially to detergent.  Detergent inside of a power
    transformer can instantly turn a working CRT filament
    winding into one that has a low resistance leak to another
    winding/ground.  Many a power transformer has been ruined
    that way.
6) a dishwasher is a deluge of water, more prudent cleaning
    is done with a gentle shower of water, directed towards
    parts that don't mind getting wet, and away from parts that

-Chuck Harris

Stan Katz wrote:
> That clinches it. Brooke's Tek tour reminded me that I have on file a
> "Service Scope" from Tek entitled "Washing Your Tektronix Equipment". I can
> follow those instructions less the drying for 24 hours in an oven at 125F.
> Doing so will probably have me kicked out of the house by the wife. A hair
> dryer will have to suffice.
> The use of a dishwasher, which I could pull off without being found out by
> my spouse, does require removing all the pots. Anyway, I think that
> dishwashing is most appropriate for boards with all surface mount chips.
> Forty year old electrolytics (all of which surprisingly have tested good)
> might balk at being machine washed.
> Stan
> On Tue, Nov 11, 2014 at 11:34 AM, Brooke Clarke <brooke at pacific.net> wrote:

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