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diode, rectifier dead?

Started by Unknown May 23, 2008
Can anyone confirm whether following microwave oven components are
dead
-diode hvr1x8019:tested with analog ohm meter-short both directions
-rectifier 2x062h 8025:..open in both directions
tnx
anglomont@yahoo.com wrote:
> Can anyone confirm whether following microwave oven components are > dead > -diode hvr1x8019:tested with analog ohm meter-short both directions
probably
> -rectifier 2x062h 8025:..open in both directions
What's the forward voltage spec of the diode? What's the highest voltage your meter can supply? if second is lower than the first it will look open.
> tnx
-- Return address is VALID! Bunch-O-Stuff Forsale Here: http://mike.liveline.de/sale.html
mike wrote:
> anglomont@yahoo.com wrote: >> Can anyone confirm whether following microwave oven components are >> dead >> -diode hvr1x8019:tested with analog ohm meter-short both directions > probably >> -rectifier 2x062h 8025:..open in both directions > What's the forward voltage spec of the diode? > What's the highest voltage your meter can supply? > if second is lower than the first it will look open. >> tnx > >
If the diode tests shorted in both directions it's bad. The one that tests open is probably good, those have a high breakdown voltage, the ohm meter can't exceed that.
<anglomont@yahoo.com> wrote in message 
news:e9ede4c8-a93c-4d40-8a59-7ecb7bb3b571@f36g2000hsa.googlegroups.com...
> Can anyone confirm whether following microwave oven components are > dead > -diode hvr1x8019:tested with analog ohm meter-short both directions > -rectifier 2x062h 8025:..open in both directions > tnx
The diode that reads short in both directions is definitely bad. The other, if it's a high voltage rectifier, might have too high Vf to be properly tested by a multimeter. Those are best tested by a Huntron Tracker or by replacement. -- Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in the address) Experience: What you get when you don't get what you want
DaveM wrote:
> <anglomont@yahoo.com> wrote in message > news:e9ede4c8-a93c-4d40-8a59-7ecb7bb3b571@f36g2000hsa.googlegroups.com... >> Can anyone confirm whether following microwave oven components are >> dead >> -diode hvr1x8019:tested with analog ohm meter-short both directions >> -rectifier 2x062h 8025:..open in both directions >> tnx > > The diode that reads short in both directions is definitely bad. The other, if > it's a high voltage rectifier, might have too high Vf to be properly tested by a > multimeter. Those are best tested by a Huntron Tracker or by replacement. >
Or test them by applying mains voltage through one to a low wattage incandescent bulb. If the diode is working, the bulb will be dim and flicker slightly running on half wave power.
<anglomont@yahoo.com>

> Can anyone confirm whether following microwave oven components are > dead > -diode hvr1x8019:tested with analog ohm meter-short both directions
** Dead for sure.
> -rectifier 2x062h 8025:..open in both directions
** Probably OK. Testing such high voltage diodes ( really a multi-diode stack ) requires a source of voltage more than what a DMM or analogue ohm meter has available. Try connecting a 9 volt radio battery in both directions, while monitoring current flow with your meter. ..... Phil
"Phil Allison" <philallison@tpg.com.au> wrote in message 
news:69pgblF346q3vU1@mid.individual.net...
> > <anglomont@yahoo.com> > >> Can anyone confirm whether following microwave oven components are >> dead >> -diode hvr1x8019:tested with analog ohm meter-short both directions > > > ** Dead for sure. > >> -rectifier 2x062h 8025:..open in both directions > > > ** Probably OK. > > Testing such high voltage diodes ( really a multi-diode stack ) requires > a source of voltage more than what a DMM or analogue ohm meter has > available. > > Try connecting a 9 volt radio battery in both directions, while > monitoring current flow with your meter.
With some sort of current limiter, like a light bulb, of course. Paul
"Paul E. Schoen Smug Pig "
> >> >> ** Dead for sure. >> >>> -rectifier 2x062h 8025:..open in both directions >> >> >> ** Probably OK. >> >> Testing such high voltage diodes ( really a multi-diode stack ) requires >> a source of voltage more than what a DMM or analogue ohm meter has >> available. >> >> Try connecting a 9 volt radio battery in both directions, while >> monitoring current flow with your meter. > > With some sort of current limiter, like a light bulb, of course. >
** Not essential. A standard 9 volt radio battery will only deliver about 200mA into a diode stack that conducts at 6 to 10 volts - plus a test takes only a few seconds. Best avoid alkaline types for this, unless it is near flat. ..... Phil
Some DMM user manuals suggest that you briefly short the diode while the
test leads are attached. This forces the meter to downrange and give a
less-inaccurate reading of the forward resistance when the short is removed.


"William Sommerwanker"

> Some DMM user manuals suggest that you briefly short the diode while the > test leads are attached.
** Must be only prehistoric ones - I bet.
>This forces the meter to downrange and give a > less-inaccurate reading of the forward resistance when the short is > removed.
** Neither manual nor auto-ranging DMMs have enough volts available on the ohms ranges to forward bias a single silicon diode - let alone a series string of them, as found in microwave oven diodes. Most DMMs have " diode test " ranges fitted, which will supply up to a couple of volts with a fixed current of about 1 mA. The reading is then in volts or millivolts. ...... Phil