15
PERIODIC MAINTENANCE
Make sure the Amplifier has been disconnected for the AC power source and the high
voltage filter capacitors have bleed down to zero.
Remove the top cover from the Amplifier at least once a year and remove the dust. Dust
accumulation can help cause the variable capacitors to arc between plates. Use the blower
connection on a vacuum cleaner or a soft bristle brush. Also, remove the tube from its socket and
check to see if any tarnish buildup has developed on the tube socket contacts. If so, use a Q Tip
and Tarn-X solution, and clean each of the socket contacts.
TROUBLESHOOTING CHART
The following charts lists specific difficulties that could occur in your Linear Amplifier. Several
possible causes may be listed for each difficulty. Refer to the Printed Circuit Board diagrams
(PCB) and the Schematic Diagrams to locate and identify the parts listed in this chart. If a
particular part is mentioned as a possible cause, check that part and other components
connected to it to see if they are defective.
AS ALWAYS, BE SURE THE AMPLIFIER POWER
CORD HAS BEEN REMOVED FROM THE AC LINE RECEPTACLE AND THE HIGH VOLTAGE
FILTER CAPACITORS HAVE BLED DOWN TO ZERO VOLTS BEFORE REMOVING THE TOP
COVER FOR YOUR INSPECTION.
TROUBLESHOOTING CHART
DIFFICULTY
POSSIBLE CAUSE
No AC power
1. Fuse F1 or F2 rear panel
2. Jumpers missing on Terminal Block TB1
3. Transformer T1
4. On/Off Switch SW2A or SW2B
5. Interlock Safety Switch SW1
6. Step Start Relay K1 or related circuitry
Multimeter inoperative in High Voltage
Function
1. Resistors R301, R302, R303, R304, High
Voltage PCB-110
2. Multimeter Switch SW401A or SW401B
Meter Switch PCB-510
3. M-2 Multimeter
Multimeter inoperative in Plate Current
Function
1. Resistors R308 - R310 LV & Bias PCB-260
2. Switch SW401A&B Meter Switch PCB-510
3. M-2 Multimeter
