Model g8688 (Mfg. 3/09+) -31-
sEcTION 7: sErvIcETroubleshooting
Motor & Electrical
Symptom possible Cause possible Solution
Machine does not
start or a breaker
trips.
1. Fuse has blown.
2. Emergency stop push-button is engaged/
faulty.
3. plug/receptacle is at fault or wired incorrectly.
4. Computer board is at fault.
5. power supply is at fault/switched oFF.
6. Motor on button or on/oFF switch is at fault.
7. Spindle rotation switch is at fault.
8. Wiring is open/has high resistance.
9. Motor is at fault.
1. Correct short/replace fuse on control panel.
2. rotate clockwise slightly until it pops out/replace it.
3. test for good contacts; correct the wiring.
4. inspect computer board; replace if faulty.
5. Ensure hot lines have correct voltage on all legs and
main power supply is switched on.
6. replace faulty on button or on/oFF switch.
7. turn switch to FWd/rEV; replace bad switch.
8. Check for broken wires or disconnected/corroded
connections, and repair/replace as necessary.
9. test/repair/replace.
Machine stalls or
is underpowered.
1. Wrong workpiece material (metal).
2. Computer board is at fault.
3. Motor speed rheostat is at fault.
4. Motor brushes are at fault.
5. pulley/sprocket slipping on shaft.
6. Motor bearings are at fault.
7. Machine is undersized for the task.
8. Spindle rotation switch at fault.
1. use metal with correct properties for your type of
machining.
2. inspect and replace if faulty.
3. test and replace if faulty.
4. remove brushes and clean/replace (refer to page
35).
5. replace loose pulley/shaft.
6. test by rotating shaft; rotational grinding/loose shaft
requires bearing replacement.
7. use sharp lathe bits/chisels at correct angle; reduce
feed rate/depth of cut; use cutting fluid if possible.
8. turn switch to FWd/oFF/rEV; replace bad switch.
loud, repetitious
noise coming
from machine
at or near the
motor.
1. pulley setsc rews or keys are missing or
loose.
2. Motor fan is hitting the cover.
1. inspect keys and setscrews. replace or t ighten if
necessary.
2. tighten f an or shim cover, or replace items.
Motor overheats. 1. Motor overload ed.
2. air circ ulation through the motor restr icted.
1. reduce load on motor.
2. Clean ou t motor to provide normal air circulation.
Motor is loud
when cutting.
overheats or
bogs down in the
cut.
1. Excessive depth of cut or feed rate.
2. rpM or fee d rate wrong for cutting op eration.
3. Cutting tool is dull.
4. gear setup is too tight, causing them to bind.
1. decrease depth of cut or feed rate.
2. refer to rpM feed rate chart for appropr iate rates.
3. Sharpen or replace the cutting to ol.
4. readjust the gear setup with a small amount of
backlash so the gears move fre ely and smoothly
when the chuck is rotated by hand