Remove the panel screws.
Carefully remove front panel and turn over.
The batteries are located underneath the right side of the front panel.
Replace the four AA rechargeable batteries one at a time to insure proper alignment.
Plug the recharger into the appropriate outlet and recharge for 24 hours.
Recheck function. If there is still no response, continue.
Check millivolt function of the pH meter.
Turn selection knob to mV (millivolt). Place electrode in fresh pH 7.0 buffer. Meter should read 15
Place electrode in fresh pH 4.0 buffer. Meter should read + 177 mV.
Place electrode in fresh pH 10.0 buffer. Meter should read 177 mV.
If pH meter responds correctly in mV mode, this pinpoints the fault to the pH board.
The pH meter needs to be serviced.
If the pH meter does not respond, you may have a faulty pH meter or faulty electrode. Proceed to
Check pH circuitry of the pH meter.
Turn selection knob to pH.
Push zero button.
This should result in a stable needle reading which can be deflected more than 3 pH units using the
If the pH meter responds correctly when shorted, the meter is in good working order and the
problem is probably a faulty electrode. Go to the next step.
If the pH meter does not respond correctly when shorted, the meter is faulty and requires repair.
Check for faulty electrode.
If a faulty electrode is suspected, replace with a new or other working electrode and recheck pH
If another electrode is unavailable, a new electrode should be ordered.
Symptom Unable to standardize meter
Check temperature knob to verify correct setting.
Open a new bottle or make a fresh batch of standard buffer and recheck standardization.
Check electrode for physical defects.