Pioneer SX 1
New Member
Hi everyone,
Bought this amp years ago and posted a thread on here asking for help. I didn't have the tools back then to carry out much or any testing so I had to lay down the project until further notice. Finally I bought myself a multimeter!
So the amp, Unit powers on indicated by the red LED on the front. However there is no action from the relay whatsoever even with the unit on for 15 mins, so obviously its detecting a problem (maybe with itself?). There is no sound from the headphone socket or speaker outputs. From reading other forums I started to carry some tests out.
All tests carried out for DC voltage with respect to ground using the negative speaker terminal.
Terminal L4 for the meter bulbs: 22.5V
TP2: 0.08v
TP4: -18.65
Now annoyingly TP4 was identical to TP2's reading when I first did it, however I accidentally brushed past the main output transistors and spark and smoke happened. Feeling suitably pissed off with myself I tested the point again, getting the reading provided on TP3 and TP4. So these will now both need replacing, and probably all 4 to keep some symmetry going in the amp itself? Can anyone tell me what a good replacement will be and where I can get it from? (UK)
Ive also seen talk in other forums about testing TR434, TR435 and TR436 but specifically only the Emitter, Base and Collector on different transistors. My question is.. Do I need to remove (desolder) the items before I can test them? And how can I work out which prong is which part? as I have read it can vary?
Bought this amp years ago and posted a thread on here asking for help. I didn't have the tools back then to carry out much or any testing so I had to lay down the project until further notice. Finally I bought myself a multimeter!
So the amp, Unit powers on indicated by the red LED on the front. However there is no action from the relay whatsoever even with the unit on for 15 mins, so obviously its detecting a problem (maybe with itself?). There is no sound from the headphone socket or speaker outputs. From reading other forums I started to carry some tests out.
All tests carried out for DC voltage with respect to ground using the negative speaker terminal.
Terminal L4 for the meter bulbs: 22.5V
TP2: 0.08v
TP4: -18.65
Now annoyingly TP4 was identical to TP2's reading when I first did it, however I accidentally brushed past the main output transistors and spark and smoke happened. Feeling suitably pissed off with myself I tested the point again, getting the reading provided on TP3 and TP4. So these will now both need replacing, and probably all 4 to keep some symmetry going in the amp itself? Can anyone tell me what a good replacement will be and where I can get it from? (UK)
Ive also seen talk in other forums about testing TR434, TR435 and TR436 but specifically only the Emitter, Base and Collector on different transistors. My question is.. Do I need to remove (desolder) the items before I can test them? And how can I work out which prong is which part? as I have read it can vary?
