Need diagnostic tips for ancient Sanwa YX-360TRe
Looks like a very standard D'Arsonval analog meter. It reads full-scale when 50 uA flows through the movement's coil. This corresponds to 0 ohms.

For measuring large-value resistors, the 9V battery would be used to power the current source, quite likely in series with the two 1.5v AAA cells.
For measuring on lowest ohm scales, the two series-connected 1.5V AAA cells would be used.

It is possible that those two voltage sources are used in series (total of 12v) on the x10k ohm scale.
When measuring ohms, half-scale is &quot;20&quot;. So when measuring on the x10k scale, a current of 25 uA would flow through the meter movement. A 200k test resistor would result in 25 uA. If we neglect the resistance of the wire coil of the D'Arsonval movement and assume that the 9V + 3V battery is used as the source, the ohm circuit would be:



simulate this circuit &ndash; Schematic created using CircuitLab
If you get no deflection of the meter's needle, chances are that the current path is broken somewhere. The schematic shown above is simplified, and doesn't show the resistors used on the other ohm scales of x1k, x10, x1. Since the batteries are connected off-board with flying wires, chances are that their contacts are faulty. The other culprit could be the selector scale rotary switch.
It is unlikely that the internal resistors used to measure ohms are faulty - they are fairly large-value and not likely to burn up.