Hello ti everyone. I'm assembled a couple of mx50 se board kit. But i've got a problem. The offset at the output from a board Is negative and the signal Is highly distorted. The other works fine. Both powered with 20 +-v DC. I'm not so experienced with the solid state. Never problem with the valve. What' s happened?
I would do like this:
-Check that output transistors are isolated from heat sink.
-Correct transistor type in each position
-Check the orientation of the transistors and that all solder joints are good.
-Orientation of capacitors
-If you cant find anything wrong, maybe check for shorts in the transistors. I do it with the beeping diode-tester on the multimeter. You can do it without desoldering first, in some cases a short might be indicated because of the circuit around the transistor, then you have to desolder and check again.
It is good to have some kind of current limiting the first time you power on the boards, then mistakes will not get so complicated (and sometimes expensive). You can use series resistors on the supply to PCB, bulb in series with transformer (HV side), bench supply with current limiting etc.
-Check that output transistors are isolated from heat sink.
-Correct transistor type in each position
-Check the orientation of the transistors and that all solder joints are good.
-Orientation of capacitors
-If you cant find anything wrong, maybe check for shorts in the transistors. I do it with the beeping diode-tester on the multimeter. You can do it without desoldering first, in some cases a short might be indicated because of the circuit around the transistor, then you have to desolder and check again.
It is good to have some kind of current limiting the first time you power on the boards, then mistakes will not get so complicated (and sometimes expensive). You can use series resistors on the supply to PCB, bulb in series with transformer (HV side), bench supply with current limiting etc.