How to detect open circuit conducting wire inside opaque sheath?

[abdulbadii]

How to detect open circuit conductor inside opaque (untransparent) insulating sheath/cable in small scale. I meant the cable diameter only 1 - 2 mm with suspected spot within 10 - 15 cm length

[hermit]

You do a continuity test with your meter.  If you don't have one you can do a simple test making a circuit up with something like a light bulb and battery.  If you are asking to specifically locate WHERE the break is, that requires more complicated/costly procedures.

[tablatronix]

Detect easy short 2 wires and continuity check.

To find it you could use a tone generator trace set, or hack something up to do it, oscillator am radio etc.

[Fraser]

If the wire is single core PVC insulated, just warm it up with a hair dryer and pull the cable. It will stretch where the break is located

That the simplest non technical test you can do.

Fraser