Fluke 336 clamp meter

[M.Joshi]

Hello,

I am trying to repair a Fluke clamp meter. One of the SMD components from the main power input to the rotary switch selector pad is damaged. The component seems to be a resistor and is painted plain green/light blue on top, similar to other resistors on the PCB. Some resistors have values printed on the paint and others don't?

I have contacted Fluke but they do not have schematics as it's a discontinued model.

Does anyone have a schematic from a clamp meter in the same series? Is the same resistor used in newer models too?

Thanks!

 

[M.Joshi]

I managed to trace back the connection from the component and it seems it connects in between the +ve rail to the !SHDN pin of an LTC1682 (Doubler charge pump with low noise regulator) when the rotary switch on the meter is in the off position (see the attached diagram).

This doesn't make sense to me if the component is a resistor as it would enable the LTC1682 when the meter is in the off position?

 

[M.Joshi]

Can anyone help with this?

 

[vtech]

I am not familiar with the specific fluke product and can not be sure if it conforms to your unit?
From what I recall, "unlabeled" SMD components were either capacitor or "zero ohm" jumpers.
In tracing back the diagram, indeed it does not make sense(According to LTC1682's application note, SHUTDN pin should be held@High)
However, there is a posting from Netherlands regarding the repair of the exact clamp as he discovers an issue with the rotary switch contacts--is it possible you may have the same problem? And if not why not try contacting him?
Good luck

(scroll half way thru the page)
https://schneiderelectronicsrepair.nl/?page_id=29