Author Topic: Fluke 175 'modification'  (Read 1325 times)

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Offline AudioFileTopic starter

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Fluke 175 'modification'
« on: October 16, 2019, 01:40:16 pm »
I recently acquired a Fluke 175 in fair condition. After servicing it works pretty much as per specification, but I see that two tracks have been cut on the pcb. These are on tracks marked with the diode symbol (see pics).
Does anyone know why such a 'mod' may have been made? I'm minded to reconnect the tracks but thought I'd check with the experts first.
The only deviation from spec is that the continuity buzzer works at 50 Ohm, whereas the spec says it should sound at <25 Ohm and turn off at >250 Ohm. I wonder if this is why the tracks were cut? Seems a drastic thing to do if so.

Help appreciated.

AudioFile

 

Offline brabus

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Re: Fluke 175 'modification'
« Reply #1 on: October 16, 2019, 02:43:43 pm »
IMvHO the "mod" only affects the backlight. The tracks seem to go to the LCD backlight LEDs, but the LEDs seem never to be mounted on those shiny pads.

The continuity buzzer function seems fine to me as well.

I wonder why someone would cut traces, without them having any effect on the function. EMC maybe?
 

Offline Paul Moir

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Re: Fluke 175 'modification'
« Reply #2 on: October 16, 2019, 02:46:59 pm »
Weird:  It looks like they've cut the traces to the backlight LEDs for the 177&179.  The LEDs go in those diode symbol footprints.   If you install the LEDs, drill a hole in your case and install a rubber button set from the 177/179 they will work.  It's almost as if someone wanted to inhibit someone from modding it by smashing up the tracks.
I'm sure my 175 doesn't look like this.
 

Offline AudioFileTopic starter

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Re: Fluke 175 'modification'
« Reply #3 on: October 16, 2019, 03:45:40 pm »
Guys, thanks for the quick and helpful replies. Yes I can see now those tracks are for the LEDs which were fitted on the 177/179 only. If it weren't for the ugly way they have been cut, I'd suspect Fluke for protecting sales of the 177 ;). I think I'll leave it alone for now.

 

Offline retiredcaps

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