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  #1  
Old 09-04-2011, 05:48 PM
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bluebrakes bluebrakes is offline
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Default Fluke 77 Multimeter stopped reading current

Hi,

my old faithful fluke 77 multimeter has stopped reading DC and AC current.
It still reads Ohms, Volts and continuity, just not current.

I found this guide here...
http://assets.fluke.com/manuals/75_77___omeng0900.pdf
although it doesn't help that the 77 pcb is slightly different to the diagram shown. i.e. I don't have a couple of the components or two fuse holders in mine.

With components being tested with another multimeter still on the fluke 77 pcb, nothing seems to be faulty. I checked the fuseable resistors and i can't seem to find anything faulty.

Has anybody else had this problem or know what component could be at fault?

Thanks.
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  #2  
Old 09-04-2011, 05:54 PM
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bluebrakes bluebrakes is offline
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photo attached of my fluke 77 board.
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File Type: jpg photo.JPG (134.3 KB, 43 views)
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Old 09-04-2011, 07:21 PM
someonesdad someonesdad is offline
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The cause for not reading current is usually one or more blown fuses, especially if the other functions work. Since your PCB doesn't have fuse holders, then the fuses must be less obvious components -- maybe you should do a continuity test on all the components.
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Old 09-04-2011, 07:32 PM
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t06afre t06afre is offline
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Take a look from page 27 and out in your manual. I think I see one empty fuse holder in the picture. But you should have 2 fuses. And I can not see the the small fuse holder at all
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Old 09-04-2011, 09:59 PM
wmodavis wmodavis is offline
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You likely left the red probe in the 10A or 300mA and tried to measure a voltage source that when presented with a near short circuit, dumped enough current into the meter to blow the replaceable fuses.
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Old 09-05-2011, 12:26 AM
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this fluke77 looks different, like in your manual... why? sure your is a 77?

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Old 09-05-2011, 12:36 AM
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Look here (servicemanual):
http://www.eserviceinfo.com/download.../Fluke_77.html
http://www.eserviceinfo.com/download.../Fluke_77.html

It says something about R1 and R2 being fusible resistors.... Don't know if it has something to do with it. There seem to exist different series of this model too.
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Old 09-05-2011, 12:37 AM
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Make sure you replace the fuse with the proper Fluke fuse.

hgmjr
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Old 09-05-2011, 05:30 AM
Jaguarjoe Jaguarjoe is offline
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Aren't those fuses like $10 or so? I popped one of mine and learned to be very, very careful when measuring current. Mistakes are costly.
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Old 09-05-2011, 01:48 PM
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Hmm.!! Where can I find fluke fuses.
I need plenty, cause I use like what comes my way.
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