Square Wave 355

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I need help...The square wave 355 machine does not have the HF when the pins D and E are closed.I have 115 VAC to gas and water valve. But, I dont have the 115 VAC to HF transfomer.When I connect the cables to primary of transformer the voltage drops to 0 VDC. With the transformer disconnected the voltage goes up to 110 VAC.The HF transformer generates the HF in secondary when I applied 115 VAC direct to it.So may anyone help me on this.`..
Reply:You have a tough machine to work on. The 115 volts starts at the power pcb. splits into two circuits, gas and HF. goes through the feed through pcb on its way to the HF transformer and the valves. Since the gas valve works. We know we have power to the power pcb and its circuit to the valve is good. We can use wire 232 as the common for our tests.You could have a bad connection in the HF circuit. For these test you will want to open the spark gap so there is no chance of it arcing. Volt meters do not like the HF and some times it will kill them. The HF 115 volt circuit starts at the power pcb plug 1J3 wire 270 goes to the feed to pcb plug 10J1. Comes out on plug 4J17 wire 228 and goes to R6 and then to HF primary.Start your tests  at the power pcb and work your way the the HF transformer. If the power drops to zero at the power pcb Check your power in on 1J6 wire 269.If wire 269 stays hot and wire 270 drops out. you have a problem with the power pcb or the # 1 plug connections. Send me a PM if we need to go into more detail.Just to compare the valve circuit is 3J3 wire 271 to 2J15 to 1J17 wire 229.Good luck
Reply:We found the problem cause. It is the power pcb. I would like to change some componentes like opto(CS5010 and MOC 3043) and TRIAC(T2500D) to pcb get back to work.Thanks for the tips
Reply:Before you go changing parts. make sure the on/off control signal is getting to the power pcb.Using a meter you should be able to see the opto coupler turn on and off and that should drive the triac.