258.
SPU AMPLIFIER TROUBLE CHART
See Section 254 |
| Trouble | Indication | Cause | Remedy |
| No Sound | | Switches or rheostates set incorrectly or input control panel. | Set switches and reostats to their proper positions. |
| | Output fader in the "Off" postion or worn one being used. (These are used in teh PG-6, PG-7 and PG-8 equipments only. | Use the proper output fader and set it int the correct position. |
| Sound can be obtained from one voltage amplifier but not from the other. | Defective voltage amplifier. | Operate using good voltage amplifier. Check bubes of defective unit when convenient. |
| Both tubes of one voltage amplifier do not light | Burned out tubes. | Replace which do not light. |
| No reading at a plate voltage jack of the metering panel. | Open "B" battery connection. | Reconnect "B" battery. |
| Voltage amplifier tubes and exciter lamps do not light. | Dirty contacts on the battery switch. | Snap the switch back and forth several times to clean the contacts. |
| Dirty contacts on the change-over switches. PG-3 equipment only. | Snap the change-over switches back and forth several times to clean the contacts. |
| Burned out fuse in four-pole battery switch box. | Turn switch to other battery and replace burned out fuse. See section 245. |
| Fuses in four-pole battery switch box burn out when replaced. | Short circuit on "A" battery line. | Check for short circuit. See section 245. |
| AC voltmeter on power amplifier panel reads zero. | AC supply circuit open. | See that all line switches are closed. Replace line fuses if they are blown. |
| AC voltmeter indicates proper voltage but amplifier tubes fail to light. | Fuses in power amplifier burned out. | Replace fuses. If they continue to blow, operate without this amplifier if possible. Reset voltage to 100 volts. If only one power amplifier is used, replace all tubes. See section 249. |
| Low Volume | Low filament voltages as measured at the metering jack. | STorage battery discharged. | Switch to the othe storage battery. |
| | Voltage amplifier defective. | Change to the other voltage amplifier if possible. |
| | Tube burned out in voltage amplifier. | Replace burned out tube. |
