Faulty auto mode switching (Aneng ST212)

[Traceless]

Hi everyone,

I have an Aneng ST212 AC/DC clamp meter here, with a faulty automatic measurement mode detection. If the meter is switched on it should stay in "auto" mode and once one starts to conduct a measurement it should automatically select the appropriate mode (voltage, resistance, continuity, etc.). However if I turn the meter on (no leads attached), it briefly goes to "auto" mode, then switches to resistance cycles through the ranges (Ohms, kOhms, MOhms), briefly switches back to auto, and then the cycle repeats. My first idea was that there might be something wrong with the isolation of the inputs - so that open circuit looks to the meter like a resistance measurement. This does not seem to be the case. If I select ranges automatically resistance measurements work pretty precise.

Mode selection seems to be performed by the relay HFD31/2.4-L2S, which audibly clicks whenever the meter changes mode. Does anybody have experience/hints on how to troubleshoot auto mode switching?

Edit: The manual DCA reading seems to be way off as well, the meter shows 0.7A without any current flow being present. Maybe just a faulty chip?