| Circuit |
Test Terminals |
Correct Effect |
Incorrect Effect |
| Indication |
Caused by |
| Grid |
G1 to frame |
5000 ohms |
Open |
Open No. 1 oscillator coil or 5000-ohm resistor or both
Shorted 0.5 mfd. condenser |
| Control grid No. 2 or G3 to frame |
5000 ohms |
Open |
Open No. 2 oscillator coil or 5000-ohm resistor or both
Shorted 0.5 mfd. condenser |
| G4 to frame |
5000 ohms |
Open |
Open secondary audio transformer No. 1, or open ground connection
Shorted or grounded transformer secondary |
| G5 to filament 5 |
Shorted |
Open |
Open connection |
| G5 to frame |
100000 ohms |
Shorted |
Shorted 0.5 mfd. condenser or grounded lead |
| G6 to frame |
110 ohms |
Open |
Open grid oscillator coil or 625-ohm resistor or 420-ohm resistor
Shorted fixed or trimmer condenser |
| G6 to P6 |
Open |
Shorted |
Shorted fixed or trimmer condenser |
G7 to frame
(Play-Off switch open) |
5000 ohms |
Shorted |
Closed or defective "Play-Off" switch grounded or shorted secondar No. 2 audio transformer
Open audio transformer secondary |
| Plate |
P1 to frame |
Open |
Shorted |
Shorted 2 mfd. condenser |
| P1 to P2 |
1100 ohms |
Open |
Open 10,000-ohm resistor or No. 1 audio transformer primary |
| P1 to P3 |
5 ohms |
Open |
Open plate coil of fixed or variable pitch oscillator |
| P1 to Lug 1 (Green) |
1000 ohms |
Open |
Open plate coil variable pitch oscillator or open 10,000-ohm resistor |
| P2 to Lug 1 (Green) |
1000 ohms |
Open |
Open primary first audio transformer |
| P4 to frame |
105,000 ohms |
Open |
Open primary second audio transformer or open 100,000-ohm or 420-ohm resistor
Shorted 0.5 mfd. condenser |
| P5 to Lug 3 (Black) |
1000 ohms |
Open |
Open 1000-ohm resistor |
| P5 to frame |
Open |
Shorted |
Shorted 2 mfd. condenser |
| P6 to Lug 3 (Black) |
1000 ohms |
Open |
Open plate coil of volume control oscillator |
| P6 to frame |
Open |
Shorted
1000 ohms |
Shorted 2 mfd. condenser
Shorted 1 mfd. condenser |
| P7 to Lug 2 (blue) |
Shorted |
Open |
Open connection |
| P7 to frame |
Open |
Shorted |
Grounded lead |
| Cathode or Filament |
C1, C2, C3 or C4 to frame |
Closed |
Open |
Open connection or lead |
| F5 to frame |
100,000 ohms |
Open |
Open connection or 100,000-ohm resistor or 420-ohm resistor |
| F6 or F7 to frame |
Open |
Shorted |
Grounded lead |
| Heater |
H1, 2, 3, and 4 to frame |
Open |
Shorted |
Grounded lead or connection |
| Miscellaneous |
Pitch control rod to G1 |
Open |
550 ohms |
Shorted oscillator resonant coil fixed condenser |
| Volume control loop to G6 |
Open |
150 ohms |
Shorted oscillator resonant coil fixed condenser |
