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Pioneer sx-1050 no voltage at output caps problem

Ok secondary voltage measurements with 117v ac at the wall
Blue-Blue=8.10vac
White-Red=44.8vac White-Red=44.8v
Brown-Green=18.8vac Brown-Green=18.8vac
Brown-Orange=58.1vac Brown-Orange=58.1vac
Those were my measurements. Anything else I should check?
 
merlynski said:
Those look pretty darn good to me, install it . . .
Click to expand...
Sounds good I will start the installation tomorrow. Question: If the wires are to short would it be better if I solder wires to excisting wires already connected to pc board posts and use shrink wrap or would it be better if I extend the wires and solder straight to pc board pins and other connection points?
 
I don't like connecting three wires together (in a Y) for a final installation. If a wire is too short I like to extend it with one wire (heatshrink the join) to the pin. I also hate changing wire colors, so, if possible I extend with a similar colored wire. I would rather have multiple wires on a pin. That seems more secure to me, and makes possible future rework easier. Those are personal preferences, electrically it makes no difference. I save wire pieces when I part out a unit so I can match them up. Yup, its OCD Perfectionism :thumbsup:.
 
merlynski said:
I don't like connecting three wires together (in a Y) for a final installation. If a wire is too short I like to extend it with one wire (heatshrink the join) to the pin. I also hate changing wire colors, so, if possible I extend with a similar colored wire. I would rather have multiple wires on a pin. That seems more secure to me, and makes possible future rework easier. Those are personal preferences, electrically it makes no difference. I save wire pieces when I part out a unit so I can match them up. Yup, its OCD Perfectionism :thumbsup:.
Click to expand...
Im with you on that one. I will use some of my existing wires from transformer being replaced to extend replacement transformer wires. Will connect each wire to connection poin, No Y connections. Thanks for everything. I will dive in tomorrow and give you a update when transformer is installed. Thanks again
 
Ok the transformer is installed now. Heres some pix of my wiring installation. Hope it all looks good. @merlynski what do you say power it up on DBT? I did re-install the heatsink but the connectors to transistors are still disconnected. 20211214_112924.jpg 20211214_113003.jpg 20211214_113014.jpg 20211214_112924.jpg 20211214_113003.jpg 20211214_113014.jpg
 
merlynski said:
Looks OK. Try it on the DBT. See if all the voltages come up some.As you know, they may be low on the DBT.
Click to expand...
Using 100w DBT bulb did light up then dim as it should for initial start up
Heres my voltage readings
AC pin2= 36.5vac
pin4= 36.6vac
pin11= 15.45vac
pin12= 15.46vac
pin13= 48.0vac
pin14= 48.0vac
DC
C1 & C2 43.9v/-43.9vdc
pin3= 44.5vdc
pin5= -44.5vdc
pin6= 56.9vdc
pin7= -57.6vdc
pin8= 17.4vdc
I took these readings at these pins and big capacitors. Hope I did the right readings. Let me know if there is something I am missing or if its looking good. Thanks
 
lopezluna said:
pin4= 36.6vac
pin11= 15.45vac
pin12= 15.46vac
pin13= 48.0vac
pin14= 48.0vac
Click to expand...

Something is wrong here:
Pin 4 is supposed to be chassis ground.
Pins 11 - 14 are regulated DC power supply output, any AC there should be minimal.

I suspect either an open connection to ground from the transformer or your meter lead is clipped on the wrong place.
 
merlynski said:
Something is wrong here:
Pin 4 is supposed to be chassis ground.
Pins 11 - 14 are regulated DC power supply output, any AC there should be minimal.

I suspect either an open connection to ground from the transformer or your meter lead is clipped on the wrong place.
Click to expand...
I have the two reds from transformer secondary connected to pin2 and pin4 just like the original wires were. I had the meter ground connected to a chassis ground. I might be taking my readings wrong. What do I go look for or is there any specific voltage readings I need to go and check again? I am not going to do anything until I hear from you
 
Awr-103 power supply board voltage readings using DBT and 100w bulb
Pin1= 17.2v
Pin2=56.2v
Pin3=-57.0v
Pin4=0 ground
Pin5=13.3v
Pin6=13.3v
Pin7= -13.2v
Pin8= -55.3v
Pin9= -28.1v
Pin10= -22.9v
Pin11 is empty
Pin12= 0 ground
Pin13=21.6v
Pin14=21.6v
Pin15=27.6v
Pin16=54.8v
Pin17=54.3v
Pin18=5.2v
Pin19=5.2v
C1/C2 44.3v -44.3v
I hope these voltage measurements are ok
 
lopezluna said:
These readings were taken off the 104 power supply pcb
Click to expand...
I was looking at the AWR-103 board, my fault :oops:

lopezluna said:
Awr-103 power supply board voltage readings using DBT and 100w bulb
Pin1= 17.2v
Pin2=56.2v
Pin3=-57.0v
Pin4=0 ground
Pin5=13.3v
Pin6=13.3v
Pin7= -13.2v
Pin8= -55.3v
Pin9= -28.1v
Pin10= -22.9v
Pin11 is empty
Pin12= 0 ground
Pin13=21.6v
Pin14=21.6v
Pin15=27.6v
Pin16=54.8v
Pin17=54.3v
Pin18=5.2v
Pin19=5.2v
C1/C2 44.3v -44.3v
I hope these voltage measurements are ok
Click to expand...
Yes, those look good on the DBT. If the bulb is still dim try full mains.
 
merlynski said:
I was looking at the AWR-103 board, my fault :oops:


Yes, those look good on the DBT. If the bulb is still dim try full mains.
Click to expand...
No worries, I quicky went and looked at the boards and realized I should have taken the readings on the 103 board not the 104. I will go try full mains in a bit and take voltage readings again from pcb 103 and will report back
 
@merlynski here are my voltage readings from pcb 103 connected to wall power. Power at wall is 115.5vac
Pin1= 22.3v
Pin2=72.5v
Pin3= -74v
Pin4= 0 ground
Pin5=13.4v
Pin6=13.4v
Pin7= -13.4v
Pin8= -62.7v
Pin9= -32.0v
Pin10= -26.0v
Pin11= -26.0v
Pin12=0 ground
Pin13=25.2v
Pin14=25.2v
Pin15=31.2v
Pin16=61.4v
Pin17=61.4v
Pin18=5.34v
Pin19=5.34v
Pin 2 and Pin 3 seem a bit off. All others are pretty close to schematic
 
Pin 2 and Pin 3 are the inputs to the +/- dc regulators, nothing else uses them, except the surge killer relay, and it is not picky. As long as they are high enough to give their regulators enough headroom they are fine.
The regulated voltages are all in spec. I would say the replacement of the transformer has gone perfectly so far.
What are the unregulated DC voltages on the filter caps C1 and C2? Those were the problem voltages the transformer was replaced for . . .
 
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merlynski said:
Pin 2 and Pin 3 are the inputs to the +/- dc regulators, nothing else uses them, except the surge killer relay, and it is not picky. As long as they are high enough to give their regulators enough headroom they are fine.
The regulated voltages are all in spec. I would say the replacement of the transformer has gone perfectly so far.
What are the unregulated DC voltages on the filter caps C1 and C2? Those were the problem voltages the transformer was replaced for . . .
Click to expand...
C1 C2 were 57.7v -57.7v a lil lower than 61v but again power coming out of wall was 115.5vac. I think you are right about how the transformer replacement has gone so far and much thanks to you mainly and a few others on this site. What do you say should be my next move now
 
You are welcome!
Did the Surge killer relay pull in? Did the Protection relay pull in? May both be a bit slow on DBT.
See if the DC offset is adjustable. It should adjust even without the output transistors connected.
Then, make sure the bias pots are set to minimum (0Ω), connect the output transistors and power up on the DBT.
Recheck and set dc offset.
Then, still on the DBT, see if the bias adjustment for one channel causes the bias to increase close to its spec. It may not go that high while on the DBT. You are just checking circuit function adjustability here. You may see the DBT bulb brighten as the bias adjustment test is made, that is normal. Turn it back to minimum.
Then do the same an the other channel.
Both should be at minimum before you go to full mains. If you leave them where they set up on the DBT they WILL be too high on full mains.

Then go to full mains. Both relays should pull in quicker. Recheck power supply voltages, including C1, C2. Recheck/adjust dc offset. Then set the bias properly for each channel. Monitor bias for a few minutes to verify it is stable.
If it is happy with those settings try some music at a low level. Use sacrificial speakers just in case. If it continues to be happy play it at a higher level and let it warm up. After the heatsink has warmed up a bit stop the music input and recheck the bias and offset. Both will vary some as it warms up.
 
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