Fluke 8010A: High test voltages on Resistance/Diode mode

[WeekendHobbiest]

Hello, everyone. My Fluke 8010A is giving me some trouble and I would like some help. Quick backstory on the meter: fleabay purchase nearly a year ago, like-new condition. Used by me as a secondary meter for V and I measurements (works well). Noticed recently that diode and resistance functions are faulty. Not sure if the problem was there before.

When testing diodes, the rating the meter gives exceeds what the diode's VF should be. When testing resistance, I get different readings. If I measure a resistor with the meter set to the proper range, the meter gives a good rating, but if I cycle through the ranges, I'll get faulty readings on some ranges.

A visual inspection of the board shows nothing concerning. I downloaded the service manual  to see if I could figure out what's wrong. I found a few out-of-tolerance resistors (R1, R11 and R12) and replaced them but that wasn't the problem. The input circuitry checks out, but from there I had a hard time figuring out how to follow through the switches on the schematic. Since the board had a low component count, I took a stab in the dark and tested all the resistors and diodes on the board and they're fine. I have no tools to test caps. Fluke's resistor network measures OK, and the reference voltage IC is spot on.

Looking closer at the service manual, on page 13, a list of voltages and current are given for the Ohmmeter. The following is what my meter is outputting versus (what the service manual rates):

200 Ohm:     2.838v - .93mA      (< .25v - 1.3mA)
2K Ohm:      2.838v - .93mA      (> 1v - 1.3mA)
20K Ohm:     .988v - 9.5uA       (< .25v - 10uA)
200k Ohm:    2.814v - 27uA       (> 1v - 35uA)
2M Ohm:      .524v - .1 uA       (< .25v - 0.10uA)
20M Ohm:     1.493v - .2uA       (> 1.5v - 0.35uA)

So my problem is high output voltages with slight undercurrent. I guess this is why readings are off.

Any thoughts or suggestions as to where I should look next? I'm pretty much a tinkerer with electronics and I've hit a wall in figuring out what's wrong here. I would love some hints or advice. Thanks.

Service manual: http://assets.fluke.com/manuals/8010A___umeng0200.pdf