|
| |||
|
|
| TROUBLESHOOTING & REPAIR | |
TOC | TOC |
| PWM OUTPUT TEST (continued) | |
Section | Master |
| ||
| 11. Using an oscilloscope, measure the PWM wave- | |||
|
|
| ||
|
|
| form from J13 pin 5 (probe) to J13 pin 4 (gnd). | |
to | to |
| See Figure F.34. The PWM waveform should uni- | |
| formly decrease as the control dial is turned coun- | |||
Return | Return |
| ||
| terclockwise to the min position. See below for | |||
|
|
| ||
|
|
| min and max potentiometer waveforms. |
|
|
|
| FIGURE F.36 – | Min./Max. Potentiometer Waveforms |
|
|
| Minimum Potentiometer | Maximum Potentiometer |
TOC | TOC |
| 0 Volts | 0 Volts | |
Return to Section | Return to Master |
| |||
10∝S/Div | 5V/Div | 10∝S/Div | |||
| 5V/Div |
|
| 12. Repeat step 11 to check the PWM waveform at J12 | 3. | Plug J3 back into the control board, J12 and J13 | |||||||||
|
| pins 4 & 5 at the left chopper board. See Figure |
|
| back into their chopper boards. | ||||||||
|
| F.37. | 4. | Locate and disconnect J1 at the control board. Also | |||||||||
|
|
|
|
|
|
| |||||||
|
| 13. Remove the load and turn the engine off. |
|
| locate and disconnect J5 & J7 at the engine protec- | ||||||||
|
| 14. If the measured min and max PWM waveforms do |
|
| tion board. See Figure F.38. | ||||||||
|
|
|
|
|
|
|
| ||||||
TOC | TOC | not match the waveforms shown, proceed to the | 5. | Check leads 90, 91, 248, and 242 for continuity. | |||||||||
continuity check section. |
|
| See the Wiring Diagram. Check for broken molex | ||||||||||
|
|
|
| ||||||||||
Section | Master | 1. Locate and disconnect J12 and J13 at each of the |
|
| pins. | ||||||||
|
|
|
|
|
| ||||||||
|
| CONTINUITY CHECK SECTION: | 6. | Check the weld terminal switch for continuity. | |||||||||
|
|
|
|
|
|
| |||||||
to | to | chopper boards and J3 at the control board. | 7. | Plug J1 back into the control board, J5 & J7 back | |||||||||
Return | Return | 2. Check leads 23, 23A, 25, & 25A for continuity from |
|
| into the engine protection board. | ||||||||
8. | If all continuity checks in this section are ok but the | ||||||||||||
|
| ||||||||||||
|
| J12 and J13 at the chopper boardS to J3 at the con- | |||||||||||
|
| trol board. See the Wiring Diagram. Look closely |
|
| voltage checks from the previous section are off, | ||||||||
|
| for broken molex pins. |
|
| replace the control board. | ||||||||
|
| FIGURE F.37 – Plug J12 Pins 4 & 5 | |||||||||||
|
|
|
| Plug J12 | |||||||||
to Section TOC | to Master TOC |
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
| |||
|
|
|
|
|
|
|
|
|
|
| |||
|
|
|
|
|
|
|
|
|
|
| |||
|
|
|
|
|
|
|
|
|
|
| |||
Pin 4 |
|
|
|
|
| Pin 5 | |||||||
|
|
|
|
| |||||||||
Return | Return |
|
|
|
|
| |||||||
COMMANDER 300 | |||||||||||||
|
| ||||||||||||
