SX-1010 project

Motnick

Motnick

AK Subscriber
Subscriber
I was able to pickup a nice SX-1010 today. It's very dirty but untouched inside. The only sign of previous work is that the protection relay has been bypassed by someone before me. Other than that it looks untouched.

It seems like these SX-x3x series receivers like me. I'm up to three now. SX-636, SX-737, and SX-1010.

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I cleaned the switches and powered up on the DBT. To my surprise the protection relay clicked right away. Too bad it's bypassed!

The DC offset seems good. One amp board has 20mV bias. The other other amp board is stuck at 0mV. I think I must have a bad output transistor? The amp does play through speakers, but it seems distorted and week though the channel with no bias.

It smells like walking into an old cabin that no one has been inside of for ten years.

I'm almost done with the restore of my SX-737. I think this one will be next. The SX-737 has went well and I hope this will be a fun project.
 
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That board next to the one with all the fuses looks a little extra crispy. You will earn your keep on this one.
It was meant to find you to save it. :D
 
That would be the power supply board. I was surprised to see how scorched it was. Hopefully I can save it.

I have been waiting all summer to find a monster amp and now it's mine. I can tell the road ahead will be a long one though. I imagine that this will take me awhile longer to restore than the SX-737 did. I'm just happy that the overall condition is good, and that no one has already tore into things before me. This looks untouched other than the protection relay bypass work.

How am I going to get that old cabin smell out though?

The SX-737 is sounding so good now, and I can only imagine how nice this SX-1010 will sound when it's put right again. Like with the SX-737, my plan is to go slow and take things one step at a time.
 
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Be careful with the power supply board, that looks very crispy and can easily crack into pieces if handled incorrectly, it needs a total rebuild.
 
Agree with TSD! Totally rebuild it. I've seen a few that were worse on here, but most that are crispy are like yours. The biggest thing you can do for it is to lift the resistors 1/4" off the board, and install heavier duty (uprated) transistors, and caps.

The problem with the amps most likely isn't in the output's but on the board itself. All of the transistors on each output board must be pulled and tested via the 6 way test http://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/. Replace without fail the 2sc1451's and the 2sa725 and 2sa726's. Replace any others that fail the test.

Relay is replaced with one in this thread. http://audiokarma.org/forums/index....-1010-939-838-et-al-relay-replacement.150439/

Latest BOM might be here, but pull the list anyway and post it here for vetting by MattSD or M.T.F. or Zebulon1. http://audiokarma.org/forums/index.php?threads/pioneer-recap-lists-sticky-suggestion.457663/
 
My first step is to get this thing cleaned up some before I begin working on it. It's nasty, and it stinks! I'm gonna blow it out with some low pressure compressed air. Can I use simple green to scrub the boards up? I have some soft brushes. I thought I might be able to scrub the boards using them, and then vacuum up with a shop vac. Is this a decent plan of action?

Here are a couple more pictures taken outside in the sunlight.

Notice the can ring on the tuner cover? That must have been where the guy set his beer can when he was bypassing the protection relay.

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After it's all cleaned up I will work on the BOM and post the entire list here before I order.
 
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I would advise against simple green, especially the purple stuff. I have used simple green and it has its own stink to it. Also it seems to be a bit harsh and unfriendly to labels. The purple stuff is caustic.

A brush and compressed air usally clean things up.

If the receiver is really dirty, like animal urine, rodents or heavy smokers I do the following.... I take the unit as far apart as I can, face plate and anything that unplugs or is paper. I soak the receiver down in windex and using a paint brush gently clean everything up. I then rinse the receiver off with water and blow it out with compressed air. I turn it on its side and place it 4-5 feet away from a very small space heater. This rapidly heats the unit up and evaporates any water. This is the key... Getting the water dried up before it can start to corrode anything. The before and after can be quite amazing.
 
I've always used the green Simple Green for my cleaning, usually I dilute it to the "light cleaning" ratio, or about 1:30 mix. Never had a problem with it taking off lettering or leaving an odor, and it gives the metal a nice sparkle. YMMV though. When you get ready to order the caps get with me so I can sub anything that is no longer available, as the lists available are all a few years old and do have discontinued parts listed in them.
 
mattsd said:
I've always used the green Simple Green for my cleaning, usually I dilute it to the "light cleaning" ratio, or about 1:30 mix. Never had a problem with it taking off lettering or leaving an odor, and it gives the metal a nice sparkle. YMMV though. When you get ready to order the caps get with me so I can sub anything that is no longer available, as the lists available are all a few years old and do have discontinued parts listed in them.
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I really appreciate the help with the BOM. I want to do as thorough of a job as I can with this receiver. I plan to keep it around for a long time once it's done. I'm sure this will take me awhile to complete, but I'm in no hurry. Right now I'm focused on cleaning and getting familiar with the layout. It seems like this receiver is similar to my SX-737 but with a little more of everything!

When you clean with simple green do you usually suck it up with a shop vac, or blow it off with compressed air? This thing is super dirty. I need to at least do some cleaning before I begin the rework process.
 
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I use Scrubbing Bubbles Bathroom cleaner. Then brush everything and rinse it all down with either 91% Isopropyl alcohol, or CRC QD Non Residue Contact cleaner. Then leave it out in the sun all afternoon. The CRC is also great for cleaning the Tuner Variable Capacitor fins. (Home Depot electrical Dept). Make sure anything that gets close to the Var. Cap is NON RESIDUE as it's a air gap capacitor and any dust, dirt, mouse poop, etc on the fins will mess with the tuning. The cover will keep 99% of it out but after 40+ years it's a good idea to clean it out also.
 
I have been working on putting together a BOM for myself based on the other threads that I have found here on the forum. I have a few things that I am coming up empty on. Hopefully you guys can help guide me on these questions? Once I have everything put together I will post the complete BOM for you guys to review.

Power Supply
1.) Part number for transistor insulators for the transistors mounted to the heat sink? (I think they are Q1, Q4, Q7.) Is 534-4673 correct?
2.) Part numbers for Diodes D1-D10? I don't see these included on any of the BOM that I have located. I know that I replaced the diodes on the PS of my SX-737. Shouldn't the diodes also be replaced on this PS?
3.) Part number for standoffs for Resistors. I have noticed comments suggesting that these resistors be mounted up off of the board to aid in cooling, Should I use some standoffs on the terminals or is there a better way?

Output Transistors
4.) Part numbers for these are not included in any of the BOM that I have found, but I know that I replaced them in my SX-737. The service manual shows two part numbers.
2SC1116A
2SA747A
I found some replacement suggestions from an SX-1250 BOM which appears to use the same parts. Would these be the correct replacement parts for the SX-1010 as well?
2SC1116A NPN = 863-MJ21194G NPN
2SA747A PNP = 863-MJ21193G PNP

Power Amp
5.) Part number for transistor insulators for the transistors mounted to heat sink? (Q9 and Q10.) Is 534-4673 correct?


6.) Part number for bleeder resistors on filter caps. I think they are R2 and R3. Should I replace these? It looks like the originals do not have very long leads left to try to reuse them.
 
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Eat your weaties that thing will fight everything you do..Ive learnt more from my 1010 then any other reciever I've done
 
Oscar23; He's asking for help, not smart - a** comments.

Motnick;

Lets take this in order of questions
POWER SUPPLY
1.) Insulators. Yes, those are what you need. TO-220 type insulators.
2.) Test the diodes. If they are testing good, no real need to replace.
3.) Better way is to make a "V" like bend in the resistor leads about 1/4" from resistor.

Output Transistors
4) Test using Echowars 6 way test. If ok, use them. If not the mj21193G and MJ21194G are the recommended replacements. Set for 25mv vs 50mv (pioneer engineers goofed on their math, per MTF and Echowars.

Power Amp.
5.) See #1.

If the Unit is running now, transistors will be ok. Just replace the ones in the BOM. If it's not working, fix the problems 1st, then rehab.

The 1010 isn't that much harder than the 737. It's just got more bells and whistles.
When you get your BOM done, post it for vetting BEFORE ordering. Once vetted, order the parts.
Larry
 
larryderouin said:
Oscar23; He's asking for help, not smart - a** comments.

Motnick;

Lets take this in order of questions
POWER SUPPLY
1.) Insulators. Yes, those are what you need. TO-220 type insulators.
2.) Test the diodes. If they are testing good, no real need to replace.
3.) Better way is to make a "V" like bend in the resistor leads about 1/4" from resistor.

Output Transistors
4) Test using Echowars 6 way test. If ok, use them. If not the mj21193G and MJ21194G are the recommended replacements. Set for 25mv vs 50mv (pioneer engineers goofed on their math, per MTF and Echowars.

Power Amp.
5.) See #1.

If the Unit is running now, transistors will be ok. Just replace the ones in the BOM. If it's not working, fix the problems 1st, then rehab.

The 1010 isn't that much harder than the 737. It's just got more bells and whistles.
When you get your BOM done, post it for vetting BEFORE ordering. Once vetted, order the parts.
Larry
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It wasn't meant to be a smart ass answer it's a comment based on my own experience and he's very wise to ask for help.. not the easiest to work on sorry if it came off that way
 
It is a difficult set to handle for a first timer. The issues are where to begin and how to limit the self inflicting damage.
An careful, organized person can make it through with help from this forum.
If it wasn't for MTF, Larry, EW and several others I wouldn't of made it. The sx-1010 was my first foray. I had a broken one and a parts set. Both were brought back to life with the help of this awesome Pioneer forum.
Still, much of the responsibility for success includes commitment from the OP. Reading past posts, finding your own answers if possible. The information gathered just in the last year is incredible. There's hardly a question that MTF or EW hasn't posted on. Of course, I know (mostly) what/how to ask Google. That's what you have to learn.
 
I have done a bunch of cleaning on the unit as it was very dirty inside. The current status is that the DC offset is fine at low volumes but runs away when the volume is increased causing the protection relay to open. Also bias is stuck at 0mV in one channel. Adjusting the pot has no impact at all. The other channel can be adjusted to 25mV just fine.

I was thinking about replacing the bypassed protection relay, and redoing the power supply and protection boards as a first step. That should give me good voltages and a functional protection circuit to begin diagnosing the offset and bias issues.

I definitely would like to fix the set before recapping everything.

Is cost the only disadvantage to replacing the output transistors, or are the originals better than the replacements? I can pull mine and test them first, but they were covered in dirt and filth. That part of the receiver has the open vents above it, and the outputs look to be in rough shape. If cost is the only issue here then I may just go ahead and replace them.

The other discovery was a lock washer in the bottom of the receiver, and a nut under the tone control board cover. I think they both came from one of the tone control pots. God only knows what kind of havoc they may have caused bouncing around inside of the receiver!
 
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