Fluke 1507 Insulation tester - High current draw - ongoing...[ SOLVED]

[omegaone]

Hi,

With power supply 6V connected rotary switch turned to any position other than off indicates a current draw of 0.9 A.
LCD does not come on, translucent panel lit. Any suggestions would help as cannot find a schematic. 

[PTR_1275]

Any photos of the PCB both sides?

[omegaone]

Pictures attached.

Before disassembly, unit completely went blank. (no display)

[PTR_1275]

Did the meter get wet? The area around the main IC and crystal looks to be corodded (blue tinge and maybe rust)

[omegaone]

This meter did not get wet, but you are correct about the blue tinge. It was recently shipped for annual calibration, and rejected because of this issue.
The battery compartment sits directly above it, I did notice this on one of the contacts for the AA battery which I cleaned. Truly appreciate your feedback because I  was not careful in looking!  I will do a proper cleaning and post back the results.

Picture of the damage is attached.

[PTR_1275]

I have a few 1507 boards that’s I got in a bulk lot of fluke stuff at work. No idea what was wrong with them for them to be removed from the cases, but some of them look to have been prodded with a soldering iron and others look untouched. I kept them because I couldn’t bring myself to throw them out. All the good parts are already taken, fuses, display etc...

Give the pcb a good clean. iPA and distilled water and then make sure you let it dry thoroughly. Hopefully after giving it a clean the power consumption drops back down to. What it should be.

[omegaone]

Battery leakage discharge residue was neutralized with vinegar  then cleaned with Isopropyl Alcohol and dried.
Battery compartment & contact was cleaned the same.

I had to modify the post as the meter exhibiting some ongoing issues. As of now, when rotary switch on Zero Ohms selection display read Volts 0.1 VDC instead of dashes and ohm symbol. If I hold down the blue selection key and power the meter rotary switch to Ohms selection, dashes flash momentarily and back to 0.1 VDC, unable to measure resistance.
At volts selection the reading is inaccurate with a known voltage (by about a 1 volt )
And the insulation test also fails on other setting.

Since unable to find schematic if anyone has a PCB please let me know.

Sincere appreciation and Thank you to PTR_1275 for his keen eyes!

[omegaone]

Rotary switch contact was not making contact on a single position caused the meter to exhibit the above behavior.
Contacts spring tension adjusted and meter is functional.