Hello all
my Hifonics Thor Vii powers on, orange power led but no audio. I powered it up after a long time in storage, it worked OK for 5 minutes then I lost all audio, any thoughts on what could be the issue?
I checked TL594CN the board is marked 5v and +12v next to it, the corresponding pins have 5v DC and 12v DC, two other pins say Out they both measure 00.1v dc
So pin 9, 00.1vdc
Pin 10, 00.1vdc
Pin 11, 12vdc
Pin13, 5vdc
Pin 15, 5vdc
my Hifonics Thor Vii powers on, orange power led but no audio. I powered it up after a long time in storage, it worked OK for 5 minutes then I lost all audio, any thoughts on what could be the issue?
I checked TL594CN the board is marked 5v and +12v next to it, the corresponding pins have 5v DC and 12v DC, two other pins say Out they both measure 00.1v dc
So pin 9, 00.1vdc
Pin 10, 00.1vdc
Pin 11, 12vdc
Pin13, 5vdc
Pin 15, 5vdc
Copy and paste the following list and fill in the blanks. If there is no blank space after the colon, add one between the colon and the numbers you enter. I makes it much easier to read.
DC voltage on all pins of the 494?
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
DC voltage on all pins of the 494?
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
DC voltage on all pins of the 494?
Pin 1: 2.131
Pin 2: 2.143
Pin 3: 3.611
Pin 4: 0.203
Pin 5: 1.514
Pin 6: 3.474
Pin 7: 0.000
Pin 8: 13.35
Pin 9: 0.097
Pin 10: 0.099
Pin 11: 13.35
Pin 12: 12.80
Pin 13: 5.005
Pin 14: 5.005
Pin 15: 5.005
Pin 16: 0.000
Pin 1: 2.131
Pin 2: 2.143
Pin 3: 3.611
Pin 4: 0.203
Pin 5: 1.514
Pin 6: 3.474
Pin 7: 0.000
Pin 8: 13.35
Pin 9: 0.097
Pin 10: 0.099
Pin 11: 13.35
Pin 12: 12.80
Pin 13: 5.005
Pin 14: 5.005
Pin 15: 5.005
Pin 16: 0.000
The power supply appears to be functioning. What's the rail voltage?
What's the DC voltage measured directly across the power supply pins on the op-amp?
What's the DC voltage measured directly across the power supply pins on the op-amp?
Any of those test points will be OK. Are the ±38 the highest voltage test points in the amp?
What's the DC voltage across the red and black 12v supply wires?
What's the resistance between the RCA shield (no RCAs plugged in) and the non-bridging speaker wires?
Is that op-amp voltage with the black probe on pin 4 and the red on pin 8?
What's the DC voltage across the red and black 12v supply wires?
What's the resistance between the RCA shield (no RCAs plugged in) and the non-bridging speaker wires?
Is that op-amp voltage with the black probe on pin 4 and the red on pin 8?
Are the grey and the violet speaker wires the non bridging? Or is it the brown and the green?
Attachments
Hi Perry
The power supply 2700uf capacitors were smelling fishy so I pulled them, the board was a mess both sides so I cleaned the electrolyte and replaced the capacitors and I have good clean audio again.
Not sure how the PS caps would have affected the output side only ever seen this on Phoenix Gold M50 previously.
The power supply 2700uf capacitors were smelling fishy so I pulled them, the board was a mess both sides so I cleaned the electrolyte and replaced the capacitors and I have good clean audio again.
Not sure how the PS caps would have affected the output side only ever seen this on Phoenix Gold M50 previously.
Attachments
OK on the caps.
Brown and green are not used for bridging.
The 12v across the op-amp may be normal but it's generally about 32v (±16v).
If you didn't remove 100% of the contaminated board, the board may burn and cause a fire hazard, even with the amp off (only B+ and ground connected).
For the shield resistance, check it with no RCAs plugged in and pushing back slightly on the jacks.
Brown and green are not used for bridging.
The 12v across the op-amp may be normal but it's generally about 32v (±16v).
If you didn't remove 100% of the contaminated board, the board may burn and cause a fire hazard, even with the amp off (only B+ and ground connected).
For the shield resistance, check it with no RCAs plugged in and pushing back slightly on the jacks.
Shield resistance measures 36.9 Kohm between rca shield and Violet and grey wire respectively. No power applied to amp.
I thoroughly removed all the contaminant with solvent spray, q tips and a brush