I've attached a screenshot of the schematic, of where I think this is. The gate symbol right next to the bottom prong of the power plug? Leads to ground? The ground wire on that circuit seems to be missing completely when I open up the bottom of the unit. It WAS there at some point, because there is solder on both the points connected by the wire in rowingcoach's picture.
Another Pioneer SX-1010 Fix-Me-Up
- Thread starter TimmahTao
- Start date
tsd71
RIP Tom Petty
Piecemealing is not the way to go, this receiver is fairly easy to work on. Fix one board or one problem and another will pop up sooner or later. My vote is to replace all the 40 year old capacitors and all the crispy problematic transistors. Then you have a unit that should give you enjoyment for many years ahead if done right.
The desire for the older gear isn't necessarily restricted to any particular area of the country that I'm aware of.
Absolutely. The 1010 is a receiver that benefits greatly from a recap and parts replacement. The power supply is ran very hot and is also very prone to failure. Pretty much every section has a known issue.
http://www.audiokarma.org/forums/showthread.php?t=437289
Here's one of MTF's and Mattsd's lists. You may need to just search the transistor number into mouser search and it will give you a new number. Some the packaging style changed or manufacturer model number but are still made. Likewise searching UPW followed by the capacitance and voltage can narrow down caps that are showing as not in stock if they are Nichicon PW. For KL just search UKL.
Here's one of MTF's and Mattsd's lists. You may need to just search the transistor number into mouser search and it will give you a new number. Some the packaging style changed or manufacturer model number but are still made. Likewise searching UPW followed by the capacitance and voltage can narrow down caps that are showing as not in stock if they are Nichicon PW. For KL just search UKL.
The 1010 is NOT a BEGINNER LEVEL unit to learn on. It's more in the High Intermediate Level to ADVANDED level. If you want to tackle it, you need to do some HEAVY READING 1st, and learn the terminology. Also comprehend what we are asking with regard to parts location. We ask for board NUMBERS for a GOOD REASON. They are individually numbered with INDENTIFIABLE Part numbers. And NO TWO ARE ALIKE. Makes it easier when you say "the transistor on the board next to the sky blue capacitor, next to pin #5." If you say, on board #, the 2sa725(Qx....x=number of the transistor from the manual/schematic) next to pin #5, it's easier to trackdown, troubleshoot, and diagnose. Look at how most of us write out the parts lists, voltage lists, etc. The way we write them out, (including part Numbers, x-ref's, Voltages including polarity, and type of voltage (-13VDC or +27VDC or 65VAC) helps everyone, again.
So lets get started.
The "motorboating"(put-put-put) and the crackles, pops, etc(Rice Krispies) are definately a symptom of the breakdown of the 2sc1451 transistors, and also 2sa726 and 2sa725's. Plus probably some Cold solder joints, marginal caps, etc. thru out the unit, but the 2sc1451 and 2sa726/725 are the MAIN SUSPECTS.
These are, as a couple on here have mentioned already, are KNOWN troubleprone transistors and MUST BE REPLACED PRE-EMPTIVELY. The chances of them being bad is 99.99999999994%, and it's a "WHEN they go bad, not an "IF" they go bad. They are #'s 1, 2, & 3 on Mark the FIXER's TOP 10 WANTED LIST for 1970's PIONEER EQUIPMENT. REPLACE THEM!
Generally the latest 1010 list is incorporated in this thread as a link. Go thru the list and VERIFY VISUALLY, Each part on yours. PIONEER did make UN-ANNOUNCED Line Changes that DID NOT make the manuals.
Once verified POST THE PARTS LIST, and it will be vetted for "Obsolete, NLA, or uprated parts". DO NOT ORDER anything until the parts list has been Visually verified BY YOU, and and vetted by one of us.
HEAVY READING LIST.. ..(Break out your Library card!)
BOOKMARK THESE
1.)http://www.audiokarma.org/forums/showthread.php?t=249745 (PIONEER TUNING FORK SERIES. A MUST for anyone working on PIONEER Equipment)
2.) PIONEER RECAP STICKY. http://www.audiokarma.org/forums/showthread.php?t=457663
3.)BiPolar Junction Transistor Testing Pay particular attention to POST #11.
http://www.audiokarma.org/forums/showthread.php?t=43186
4.) DIY Forum repair & restoration reference threads
http://www.audiokarma.org/forums/showthread.php?t=426532
5.) Another from ECHOWARS....
"So You Want To Repair Audio gear, Eh? Here's the tools you need..."
http://www.audiokarma.org/forums/showthread.php?t=333423
6.)Sx1010 BOM List ( This is the list for the 1010 in Item #2. )
http://www.audiokarma.org/forums/showthread.php?t=514144
VERIFY this against your unit 1st then post the list on this thread for VETTING. DO NOT ORDER until vetted. (This helps everyone. You get the latest list, and we can take the latest list and change Item #2 above, so future users will have a current version. )
7.)Pioneer SX-1010, 939, 838, et.al., Relay Replacement
http://www.audiokarma.org/forums/showpost.php?p=6759577&postcount=30
So lets get started.
The "motorboating"(put-put-put) and the crackles, pops, etc(Rice Krispies) are definately a symptom of the breakdown of the 2sc1451 transistors, and also 2sa726 and 2sa725's. Plus probably some Cold solder joints, marginal caps, etc. thru out the unit, but the 2sc1451 and 2sa726/725 are the MAIN SUSPECTS.
These are, as a couple on here have mentioned already, are KNOWN troubleprone transistors and MUST BE REPLACED PRE-EMPTIVELY. The chances of them being bad is 99.99999999994%, and it's a "WHEN they go bad, not an "IF" they go bad. They are #'s 1, 2, & 3 on Mark the FIXER's TOP 10 WANTED LIST for 1970's PIONEER EQUIPMENT. REPLACE THEM!
Generally the latest 1010 list is incorporated in this thread as a link. Go thru the list and VERIFY VISUALLY, Each part on yours. PIONEER did make UN-ANNOUNCED Line Changes that DID NOT make the manuals.
Once verified POST THE PARTS LIST, and it will be vetted for "Obsolete, NLA, or uprated parts". DO NOT ORDER anything until the parts list has been Visually verified BY YOU, and and vetted by one of us.
HEAVY READING LIST.. ..(Break out your Library card!)
BOOKMARK THESE
1.)http://www.audiokarma.org/forums/showthread.php?t=249745 (PIONEER TUNING FORK SERIES. A MUST for anyone working on PIONEER Equipment)
2.) PIONEER RECAP STICKY. http://www.audiokarma.org/forums/showthread.php?t=457663
3.)BiPolar Junction Transistor Testing Pay particular attention to POST #11.
http://www.audiokarma.org/forums/showthread.php?t=43186
4.) DIY Forum repair & restoration reference threads
http://www.audiokarma.org/forums/showthread.php?t=426532
5.) Another from ECHOWARS....
"So You Want To Repair Audio gear, Eh? Here's the tools you need..."
http://www.audiokarma.org/forums/showthread.php?t=333423
6.)Sx1010 BOM List ( This is the list for the 1010 in Item #2. )
http://www.audiokarma.org/forums/showthread.php?t=514144
VERIFY this against your unit 1st then post the list on this thread for VETTING. DO NOT ORDER until vetted. (This helps everyone. You get the latest list, and we can take the latest list and change Item #2 above, so future users will have a current version. )
7.)Pioneer SX-1010, 939, 838, et.al., Relay Replacement
http://www.audiokarma.org/forums/showpost.php?p=6759577&postcount=30
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Neat; I'll start reading. Seems that may be a little over my head at the moment, but the beginning is the only place to start. I assume some of you might have been beginners at one point, although some of you may have forgotten.
I had already had read some of those threads, particularly the ones with parts lists. Once I figure out which versions of the boards I have, I'll put together a list.
Frankly though, it sounds like most are telling me that I should leave this one to the professionals. Ugh. The power supply was actually already rebuilt, as far as I can tell; it has new nichicon caps, but the amp boards both have those pesky transistors on them and the original caps. How much should I budget to have the other boards rebuilt?
SX-1010 dreams are one thing.......SX-1010 Nightmares are a totally different animal, right, Mike?!? I get one every once in a while where it does nothing but PUKE 1451's and 726's.....Right thru the Tape Monitor switch openings. YUCK!!!
Timmahtao....most everyone here that has posted in this thread, Either has a 1010 now, and has rebuilt it, or HAD one at one time, and it was rebuilt. So there is a lot of experience here. Then there is MARK The FIXER who has over 30 years experience and is one of 2 UNDISPUTED PIONEER HIGH END MUCKY MUCKS and GURU's here.
If he say's such and such is broke and this is how you check, do exactly as he says. No more. Bets are, with his experience level with them, he can rebuild them while asleep, and it'll be right the 1st time. So you can take his advise and suggestions to the bank. He's very busy right now and doesn't get on the board much but he'll get on and eventually put in his $20.00 worth either to back the rest of us up, or to note something that we might have missed.
So if Mark gets on and asks for voltges on a certain part on a certain board, do it, and do nothing else until he clears the issue.
Between Mike, Zeb and myself, we can cover you on the problems. Take the parts list and compare it part for part and note changes. Then post it all in the thread. We'll get it vetted and then you can go ahead and order the parts.
Total parts for a 1010 is about $125.00. You won't need the new output transistors emitter resistors (unless they are burnt, but I don't think they are.....We'll get to that later)
Timmahtao....most everyone here that has posted in this thread, Either has a 1010 now, and has rebuilt it, or HAD one at one time, and it was rebuilt. So there is a lot of experience here. Then there is MARK The FIXER who has over 30 years experience and is one of 2 UNDISPUTED PIONEER HIGH END MUCKY MUCKS and GURU's here.
If he say's such and such is broke and this is how you check, do exactly as he says. No more. Bets are, with his experience level with them, he can rebuild them while asleep, and it'll be right the 1st time. So you can take his advise and suggestions to the bank. He's very busy right now and doesn't get on the board much but he'll get on and eventually put in his $20.00 worth either to back the rest of us up, or to note something that we might have missed.
So if Mark gets on and asks for voltges on a certain part on a certain board, do it, and do nothing else until he clears the issue.
Between Mike, Zeb and myself, we can cover you on the problems. Take the parts list and compare it part for part and note changes. Then post it all in the thread. We'll get it vetted and then you can go ahead and order the parts.
Total parts for a 1010 is about $125.00. You won't need the new output transistors emitter resistors (unless they are burnt, but I don't think they are.....We'll get to that later)
Haven't analyzed the WHOLE thread, but here's a stab:
1. putt putting - pull the pre-power jumpers and note ANY changes.
2. cleaning versus DEOXITING. Cleaning leaves clean corrosion. DEOXITING loosens the corrosion's hold to the GOOD metal, to where repeated actuation of the control scrubs down to GOOD contact. EVERYTHING that goes in n out, up n down or roundy round is a candidate. Faderlube AT LEAST the pots afterwards (roundy round) to prevent premature wear out) and a day or so later after successful deoxiting faderlubing everything won't hurt.
Then reevaluate. everything.
Don't run it MUCH, until those funny 2sc1451's are OUT of the amp - the potential for $ damage is fairly large. It CAN be fixed, but if it ain't broke - DON'T break it!!
ditto on those pictures - we can tell you a LOT from them.
And if the LOUD pops don't deoxit out or happen WITH the pre/power jumpers out, then it's priority power off and a lot of preemptive stuff. Can you contact the former owner to find out what he did, or who did it?
What is the DC offset voltage AT the speaker terminals for each channel (l/r) - it obviously is the same for a/b/c on the left or on the right.
1. putt putting - pull the pre-power jumpers and note ANY changes.
2. cleaning versus DEOXITING. Cleaning leaves clean corrosion. DEOXITING loosens the corrosion's hold to the GOOD metal, to where repeated actuation of the control scrubs down to GOOD contact. EVERYTHING that goes in n out, up n down or roundy round is a candidate. Faderlube AT LEAST the pots afterwards (roundy round) to prevent premature wear out) and a day or so later after successful deoxiting faderlubing everything won't hurt.
Then reevaluate. everything.
Don't run it MUCH, until those funny 2sc1451's are OUT of the amp - the potential for $ damage is fairly large. It CAN be fixed, but if it ain't broke - DON'T break it!!
ditto on those pictures - we can tell you a LOT from them.
And if the LOUD pops don't deoxit out or happen WITH the pre/power jumpers out, then it's priority power off and a lot of preemptive stuff. Can you contact the former owner to find out what he did, or who did it?
What is the DC offset voltage AT the speaker terminals for each channel (l/r) - it obviously is the same for a/b/c on the left or on the right.
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Oh, I mean I totally believe that you guys know what you're talking about. Including when you say that this may be a bit above my pay grade at this current time.
So other than reading, I was wondering if maybe I should start with an easier project. My father has an old SX-626. He doesn't know if it works, or where it came from, but he said I can have it if I want.
Would recapping something simpler, something less powerful, and something free-er be a better place for me to start?
Eeeeyyyyy, MarkTheFixer!
I actually dropped it off today at another AudioKarma members house near my work. He has a little more equipment than me, and I asked if he could help me do some of this stuff, like testing the amp and pre-amp separately.
I also might pay him to replace those transistors pre-emptively so that I don't have to worry about them blowing everything to hell as I work through the rest of this stuff slooooowwwwwly as I learn. Plus, it'll give me time to put together a dim-bulb tester!
Unfortunately, as soon as I mentioned I was having problems, the former owner fell off the face of the planet. I am on my own. I'll get more and better pictures later in the week. Give my macro lens some work to do!