New Pioneer day! aka. another SX-1010 restoration

Learned my lesson, really hope I dodged a bullet. The thing was I had the DBT in line but it wasn't brightly lit enough to concern me. At the limited 34V DC, the heatsinks were cool to the touch.

I am going to pull the transistors to re-apply insulators/thermal paste tomorrow. This receiver runs warm, it seems. Even with the voltages within tolerance (10%) the power supply heatsink runs so hot, I can hardly believe it. I may buy a small fan for my cabinet at home.

What I would do is to get some of those little heatsinks with the adhesive on them for the regulated supply as pictured. The ones I had on hand I needed to bolt on, but if you have to order some I'd get the adhesive, ones, a lot easier to fit.That is of the most concern, the actual amplifier itself doesn't run hot enough to be of concern.

Having said all that, I always run Pioneers idle current less than what the manual states, the SX1250 for example, I am running that at 65mV instead of 100mV. Pioneers do seem to idle hotter than is necessary.
This helps a lot with heat at idle, and it doesn't affect the sound contrary to popular belief.
I can't remember what the SX1010 idles at, but you could come down 10-15% in mV.

IMG_6193.JPG
 
What I would do is to get some of those little heatsinks with the adhesive on them for the regulated supply as pictured. The ones I had on hand I needed to bolt on, but if you have to order some I'd get the adhesive, ones, a lot easier to fit.That is of the most concern, the actual amplifier itself doesn't run hot enough to be of concern.

Having said all that, I always run Pioneers idle current less than what the manual states, the SX1250 for example, I am running that at 65mV instead of 100mV. Pioneers do seem to idle hotter than is necessary.
This helps a lot with heat at idle, and it doesn't affect the sound contrary to popular belief.
I can't remember what the SX1010 idles at, but you could come down 10-15% in mV.

View attachment 1262689
I must be learning something because that's exactly what I did! (sorry, left my phone at work or else I'd take a pic) I have 2 heatsinks on it very much like your pic.

Idle current is recommended 50mV so I'll try that.
 
service manual is wrong.
Set to 25mV's
WTF!!!

While we are on the subject of voltages, is there anything I should do about pin 15 that feeds into the control amp and EQ in the power supply. It's about 15% higher than it should be. I could replace the 2W resistor to a higher value from 1.2k?

pin (spec) measurement
14(56) 59

15(24) 27.7

10(-56) -57.9

11(-24) -23.6
 
I found the post, previously explaining the mistake in the service manual. Wow. Thank you both for the assist on this one, I am chomping at the bit to put this 1010 to use but I am not going to rush when the end is so close!!
 
Here's an example of how fragile these Power Supply boards get. I was pulling a leg to test R18 and the other end just detached from the foil and took a chunk of the PCB with it.
 

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Here's an example of how fragile these Power Supply boards get. I was pulling a leg to test R18 and the other end just detached from the foil and took a chunk of the PCB with it.
Yeah, pretty standard for a PCB of this age. You need to be super careful and use a decent solder extractor.
I use a Pace Xtractor which is part of the Pace MBT Solder station I have, it runs off the air on my compressor, its the only way to reliably remove solder from these boards without damage.
 
While I wait for the lights and other minor bits to arrive, I was browsing ebay and came across this listing and a mod of the power supply . interesting way of dealing with the heat issue.


s-l1600 (4).jpg s-l1600 (5).jpg
 
While I wait for the lights and other minor bits to arrive, I was browsing ebay and came across this listing and a mod of the power supply . interesting way of dealing with the heat issue.


View attachment 1269099 View attachment 1269100
Yeah pretty much what has to happen to the SX1980 pass transistors, they run super hot too, but they are relocated to the main heatsink assembly, those ones are just on the chassis, I like the additional heatsink idea personally.
 
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