Ideal 61-494 multimeter confused about ohms

[castironman]

Hello, I am Joe and I am the second owner of this meter. I am having problems reading resistance with it. It reads 0.00 ohms with the test leads connected on the selector to ohms, but can only read something when about 150 ohms and good after +/- 200 ohms. The display flashes many times when you move the selector ( I think as it goes through the ranges ) and takes a long time to sense that the leads are connected to something, like it takes its time, then flashes then undershoots then reads. But here is something I found interesting, it is flawless when I move the selector to continuity test. It beeps and has no problem reading as low as 5.6 ohms, very fast. I measure the output current and at the ohms selection reads 0.49mA and at the continuity test selection reads 0.79mA.  I am just trying to understand what is the difference, I am an electrician not electronics repair. Can you guys please help me ?

[Gregg]

I’m assuming that an electrician already checked the battery.  Next step would be to carefully take it apart and clean the rotary switch contacts and while apart look for any solder joints or components that look dodgy. 
Ideal rebranded the meter but I’m sure somebody on the forum recognizes it and will offer further help.

[helius]

It's a rebranded APPA 107N.
Normally shorting the leads does not read 0.00 ohms unless the REL function was used to null out the lead resistance.

[castironman]

Hello, Gregg, thank you for your help, first thing that I came up was to replace the battery. Then I took it apart and checked the rotary and I use a magnifier looking for something burn or anything else. I could not find nothing. I will do it again later. Thank you for your help, Gregg.

[Gregg]

Also clean the board under all of the push buttons as well as the part of the push button that is supposed to make contact with the traces on the board.  Your entire problem may be with the meter sensing that a button is pressed when it isn't because of some crud on the board.  Use 99% isopropyl alcohol or contact cleaner that you are sure won't attack solder mask or plastics. 
Electrician's meters often see less than ideal conditions and if you can't fix it buy a meter that you can trust your life to.  I personally use my Fluke 189 that I have had for 20 years; it has never glitched. 

[castironman]

Hello, Helius. Thank you for the link, I did not have the rel pressed, I am navigating more towards the difference between the testing amperage, lower at the resistance test than the continuity test, I tested on my 117 and it reads 0.298mA on booth selections, the same amperage. In my logic I think it uses that fixed amperage to get resistance through Ohms law, but somewhere in the circuit something has failed, so I have that amperage drop or higher resistance, next I will look for the chipset information Maxim max134cqh 0037.
Just learning here. Thank you for your help.

[castironman]

Visiting an old post, I found the problem with my multimeter a few months ago. Andy from APPA (thank you, by the way) send me a troubleshooting manual for that meter and SMD resistors R2 and R5 are out of specs. They are parts of the RS and Vref input for the Maxx processor. That is why I got such strange behavior.