DarrenA
Well-known member
OK, so I recently got a Space Invaders II color cocktail and I am working on repairing it.
But I have some issues I need an assist with.
First was the power Supply, it had No +5 or -5 output. I traced all of that section and found a pile of faulty parts, (about 10) from Diodes, resistors, to the high speed switching transistor. I replaced them all and now with NO load it has a nice 5.09 volt and -5.01 output.
BUT when I install the game board, the voltage on the +5 buss drops to 3.75 or lower.
Would "failing filter caps" on the +5 output cause this type of load drop?
Also what is a good test to do for a "load test" on a switching power supply?
I remember reading something about adding a resistor from +5 to ground to simulate a load but I can't find that anylonger.
But I have some issues I need an assist with.
First was the power Supply, it had No +5 or -5 output. I traced all of that section and found a pile of faulty parts, (about 10) from Diodes, resistors, to the high speed switching transistor. I replaced them all and now with NO load it has a nice 5.09 volt and -5.01 output.
BUT when I install the game board, the voltage on the +5 buss drops to 3.75 or lower.
Would "failing filter caps" on the +5 output cause this type of load drop?
Also what is a good test to do for a "load test" on a switching power supply?
I remember reading something about adding a resistor from +5 to ground to simulate a load but I can't find that anylonger.