I have inherited a Pioneer SX-1010. Apparently it was used very little and sat in storage for about 10 years. Initially it would produce only loud pops and crackles when turned on. I googled the unit and found your site. As recommended here, I removed all the knobs (including the tuning knob) and cleaned the potentiometers (using Radio Shack's contact cleaner). I removed the top and bottom covers and dusted using an air compressor. I then connected my CD player to the AUX connections. Listening through headphones, you can now hear music - with just a bit of crackle in the background. However, when I connect it to speakers (Sansui S-517, max 65 watts), there is only very loud pops and crackles - which I don't play for more than a fraction of a second. I tried all three speaker connections - A, B and C, and tried tape 1 and tape 2 monitor connections - same loud pops. This is the first receiver I've opened - so I'm new to this. I do have a multimeter (not sure what to check). And I snapped some photos of the various boards and components - if that would be helpful. JohnM

I have a 1010 as well with the same problem. I am pretty sure that it is a bad capacitor that is causing this. Freeze spray should isolate the problem.

If its really loud crackles, then some small tranistors in the differential input of the main amp are bad. You can isolate the bad ones with some freeze spray, but don't use your main speakers for this research! Old headphones or some speakers with 10..20 Ohms additional series resistor are ok.

Welcome to AK. I would suggest a more thorough cleaning with Deoxit of all controls and even suggest cleaning the RCA inputs on the back with Deoxit (Q-tip w/ Deoxit, followed by dry Q-tip). The Radio Shack stuff will not cut the mustard/deoxidation. What follows is a basic primer on cleaning:

1) Unplug the unit. Electricity + liquid = shock.
2) Open unit.
3) Spray deoxit into pots one at a time. Pots are the moving thingies inside the unit on the other side of the knobs and buttons you use to operate the unit. Use three good bursts per pot or one good burst for every obvious hole in the pot. An old towel on the bottom will save your work bench from the drips.
4) Do not spray the tuner gang. If you do not know what this is, stick to spraying the moving thingies that are just on the other side of the knobs and buttons. Don't fret if any deoxit gets on the boards -- it's OK.
5) Turn each knob, switch, or button (on the outside) full range in a gentle but firm fashion after spraying its corresponding pot on the inside. Do this about 50 times per pot. The object is to spread the deoxit around.
6) Let dry overnight. You can let it dry less, but why take the chance.
7) Close unit.
8) Play and enjoy.

AFTER you use the de-oxit:

If the pops and crackles are on both channels and switching to mono doesn't change the character of the pops and crackles, the problem could be in the power supply.

there are pre-out / power amp in jumpers on the lower left side of the back panel, remove them momentarily and see if the pops and crackles continue.

Check the power supply board for bad solder joints, especially around the transistors that heat up, after 20 - 30 years they crack and fail.

also the phono circuit, without any inputs, is the popping and crackling worse from it, the circuit can disturb the power supply voltages when it fails.
I have seen this on two sx-838's ...

from the info I have, the 1010 does have two seperate power amp boards, one for each channel. That exonerates the offset control circuits's diode as there is one on EACH power amp board. also the offsets are run off of the main b+ and B-.


The power supply is definitely a strong suspect. you can measure the dc and ac voltages of the power supply outputs if you have a dmm.

I can send you what I have on the unit if you PM me your email. also if you wish I can mark up extra copies of what I am sending to indicate what to read and where with the power supply. I can also recieve the photo's you took and also use them to help decipher this problem, as the sx-1010 information I have is incomplete, and in one case very difficult to open and use because it's so big.

I have a paper copy of the manual which I could scan partly, but my time is limmited as I am on a business trip the next 2 days. If still needed, I can do the scanns afterwards.

Read the first post in THIS THREAD (http://audiokarma.org/forums/showthread.php?t=5634) and follow the instructions. You will probably need a schematic/service manual for your amp. This will eliminate at least one possible cause, and maybe yield a clue as to where to look next. Do the simple stuff first!

Also, you might want to try Fader Lube (another DeOxIt product) instead of the standard cleaner, or in addition to it, on the pots.

agger:

I have sx-1010 .jpgs of:
1) power amp schematic and foil layout
2) control amp schematic and foil layout
3) power supply schematic and foil layout
4) protection circuit schematic and foil layout

and a 3.2 meg jpeg of the FULL schematic, that is impossibly large to open by any program I have other than the kodak photo imager program. paint and microsoft photo editor can't.

so EVENTUALLY it would be great, I suspect this fix will take longer than your trip.

<snip>As recommended here, I removed all the knobs (including the tuning knob) and cleaned the potentiometers (using Radio Shack's contact cleaner). I removed the top and bottom covers and dusted using an air compressor. <snip>. This is the first receiver I've opened - so I'm new to this. I do have a multimeter (not sure what to check). And I snapped some photos of the various boards and components - if that would be helpful. JohnM

John, the shafts of the pots are usually sealed by an o-ring to keep stuff from in front of the unit from getting through (coffee, pop smoke etc..). Cleaning or deoxiting almost always has to be done from the inside of the reciever to find holes that the stuff can be sprayed in to, both in the pots AND the switches.

I had an sx-636 I wrote off years ago seeing that I knew the problems were the pots and switches, and I couldn't get replacements any longer, so I put it in storage. It had weird multiple symptoms. AFTER I used deoxit on it - I was *&%$%#@ AMAZED. It's fine, I've used it daily for years without doing anything else to it except replacing the broken glass faceplate.

I also have a paper manual for the SX-1010. If you need something scanned, Pm me.

a 3.2 meg jpeg of the FULL schematic, that is impossibly large to open by any program


Also, I have software that can resize, resample or break into smaller pieces the 3.2 mb jpeg file if you would like that done.

Thanks for all of your suggestions. I stepped through them and think I've narrowed it down to the power supply, and am taking it to a local service tech. They require a deposit of $50.00 up front for the estimate. But I'm not sure what the maximum service charge on a unit like this should be. If able to be fixed, I plan on keeping it to listen to albums, CDs, FM, etc.