CAUTION
Never remove or insert the AC plug when the unit is on or the AC power switch is in the “ON” position. Obstruction of the top portion of the amplifier will result in the tubes overheating.
TROUBLESHOOTING GUIDE ________________________________________
SYMPTOM | CAUSE | REMEDY |
|
|
|
Hum or “Buzzing” in | Ground loop | Install |
speakers |
| on AC cord to float the ground |
| 300B tube with high plate |
|
| current too high | Check bias of 300B. If high, |
|
| readjust to proper bias setting |
|
| of 60 mA |
| Intermittent or poor connection | Replace bad interconnect cable |
| of interconnect |
|
|
|
|
“Popping” or “Spitting” | Noisy tube | If noise is in one channel |
noise |
| through the speaker, swap one |
|
| section of tubes at a time until |
|
| the noise swaps channels. |
|
| Replace the noisy tube. |
| Check bias of output tubes | If high or fluctuating rapidly, |
|
| replace output tube |
|
|
|
AC fuse blows | Line voltage surge | Replace fuse |
|
|
|
Tube fuse blows | Shorted tube (300B & | Replace tube |
| 845 have separate fuses.) |
|
|
|
|
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