In article <n8udnegY_ZBzMafVnZ2dnUVZ_j-dnZ2d@comcast.com>,
 "William Sommerwerck" <grizzledgeezer@comcast.net> 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.

"William Sommerwanker  Snipping Cunthead "

>>> 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   -  fuckwit ??


> 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  -  fuckwit.

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


**  What a pathetic excuse for a liar.



.....    Phil

>> 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.

"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

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.

"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

"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 

<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

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> 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