MyLastWord
Active Member
Is this transformer went BAD, when the resistor value on the primary side (say 2.9ohm) lower or equal to the secondary sides (say 2.9 and 5.4ohm)? This is the transformer from a dead Pioneer SX-980.
@rcs16, Forgive me for contradicting you, but the circuit connected to pin 12 and 13, comprising of D6, D7, C23 and C10 is a +24vdc full wave rectifier driven by the green leads and grounded brown center-tap transformer secondary. This is followed by the +13vdc regulator.You need to learn to isolate circuits, suggest isolate the transformer secondary in order to determine if it has issues. Any component in the secondary circuit could cause the secondary fuses to blow.
the ckt connected to 12,13 is a voltage doubler, check/change C23 (2200uF/35V) and if that does not do it, check the rest of the parts in the 13VDC regulator.
So after I built the DBT, and connect the receiver (SX-980) to it to check some voltage reading. Upon power it up, the bulb went bright then dim. Recheck vac of pin12 and 13, each measure at about 26vac. Then measure the voltage at D6, D7 and it only show about 9.5vdc, not good..