How do you troubleshoot this kit?. I have assembled a number of kits over the years.
I assembled this kit recently but cannot measure any voltage at VAC or Load. The jumper is correctly set for 125 V, (USA). It is getting 120V at the mains connector. The resistor R7 is 10K for 60Hz operation. If I measure the voltage at the transformer it is 125V at the center tap and 250 at the end tap. The transformer is mounted correctly with 7V and 14V measured on the low voltage side. I have checked that all components are correct and fuses have not blown. A careful check of the board below shows no solder bridges and all joints look shiny and do not appear dry. Electrolytic capacitors have correct polarity. All diodes have correct polarity. The transistors and Triac have been mounted as expected. No component appears damaged, no solder joint appears dry.
I am beginning to suspect that one component is damaged. Are there any locations that I should measure a voltage to determine which components may be suspect.
Any suggestions would be appreciated.
Iain Grant