Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default diode, rectifier dead?

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
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Default diode, rectifier dead?

wrote in message
...
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


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Default diode, rectifier dead?


DaveM wrote:
wrote in message
...
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.


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Default diode, rectifier dead?




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


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Default diode, rectifier dead?


"Phil Allison" wrote in message
...



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


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Default diode, rectifier dead?


"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



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Default diode, rectifier dead?

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.


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Default diode, rectifier dead?


"William Sommer******"

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






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Default diode, rectifier dead?

Some DMM user manuals suggest that you briefly
short the diode while the test leads are attached.


Must be only prehistoric ones -- I bet.


If the Fluke 87 is prehistoric, you lose.

The Fluke 87 does have a separate diode test. However, I'm almost certain I
read what I read in the 87's manual -- but I'm not sure, and I don't have
the time to look for it.


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Default diode, rectifier dead?


"William Sommer****** Snipping ****head "

Some DMM user manuals suggest that you briefly
short the diode while the test leads are attached.


Must be only prehistoric ones -- I bet.


If the Fluke 87 is prehistoric, you lose.



** Where is your proof - ****wit ??


The Fluke 87 does have a separate diode test.


** Yawwnnnnnnn


However, I'm almost certain I
read what I read in the 87's manual -- but I'm not sure,



** You are not sure if your arse is on fire or not - ****wit.

and I don't have the time to look for it.



** What a pathetic excuse for a liar.



...... Phil







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Default diode, rectifier dead?

In article ,
"William Sommerwerck" wrote:

Some DMM user manuals suggest that you briefly
short the diode while the test leads are attached.


Must be only prehistoric ones -- I bet.


If the Fluke 87 is prehistoric, you lose.



Bzzzt. If the Fluke 87 is prehistoric, he wins.
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