Triplett 630 NA Type 3 Reads low on x10ohms

[Burrjennings]

A 630 NA Type 3.  Reads way low on x10ohms.  New batteries, new fuse, cleaned ohms adjust and range switch.  I'm somewhat of a beginner with circuit diagrams, but it looks like the end of each resistor is wired onto the range switch and is therefore out of the circuit until engaged by the switch.  So I reasoned that the resistors could therefore be checked with my DMM without de-soldering.  All resistors on the rosette read good.  I've had others on another blog suggest a loose solder connection.  I thought I'd try this blog to see if there is any advice on troubleshooting/repairing this meter.  Thank you.