Analog multimeter fault repair Ohms

[cleanworkbench]

 I have a analog multimeter  30 years old now  and it has developed a fault .  On X10K range it is fully adjustable to beyond  zero ie the right hand side ,  but on ranges  X1K,  X10 and X1 it can only be adjusted up to 2/3    two thirds  of FSD ?.  On all other functions it works perfectly ,  does anyone have any suggestions to where i can start to repair this weird fault please.
There is no sign of damage inside the case ie the circuitry .

[Kleinstein]

A frist point would be to check if the batteries are still OK. Old dry cells (non alkaline) can be to weak tot deliver the required current.
The protection with the old meters often was not that good - so a damage to some internal resistors is possible.

The old meters were a bit different in how the realized the resistance functions. It could help to know the meter type and if a vailable get a schematics.

Are the other functions working ? Parts can also be shared with the current ranges.

[wasedadoc]

Yes, check the battery. Some meters had two different batteries. A higher voltage one for the highest resistance range.