> I tested my dummy load after disconnecting the HV section and the HEPS went to ticking mode.
> However, it worked when connected to the scope.
> I think I have double checked all the connections, but I may be wrong...
> Does anyone used the resistors values that Dennis Tillman suggested for the dummy load?
When I made my dummy load for the 7904 I used the following load resistors:
+130? 2K2 20W
+50? 240R 20W
+15? 82R? 5W
+5? 10R? 5W
-15? 100R 5W
-50? 240R 20W
I also connected indicator LEDs to all the outputs for a bit of extra current through the following resistors:
+130? 5K6 5W
+50 and -50? ?2K 5W
+15 and -15? 750R 1W
+5? 220R 1W
I? installed a couple of LEDs in the dummy load through 470R resistors to the appropriate pins of P1417 to check the light supplies.
I know there resistors in the HEPS between the sense inputs and the outputs but I installed a P1483 plug which is the sensing one and connected it to the corresponding outputs from P1482 "just in case". It works well and helped me fix the HEPS. FWIW the problems I've encountered have all been faulty LV rectifier diodes and caps which cured the ticking, and faulty focus &? DC restorer diodes and 22M resistors in the HV section which cured focus and display problems.? It's such a pain to work on that HEPS that once it's apart I preferred to change them all rather than have to go back in.
Good luck!
Morris
