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Pioneer SX-1250

pin 1 - -75.8v -62v raw dc speaker power out
pin 2 - 76v +62v raw dc speaker power out
pin 3 - 0V 0v ground
pin 4 - should be no reading AC power input
pin 5 - should be no reading AC power input
pin 6 - 92.1v +85v raw dc in
pin 7 - 25.2v +23v raw dc in
pin 8 - 6v +5.4vregulated dc out
pin 9 - 13v +13.5v regulated dc out
pin 10 - 25.1v +25v regulated dc out
pin 11 - 66.8v +65v regulated dc out
pin 12 - 0v ground
pin 13 - -91.8v -65v regulated dc out
pin 14 - 1.1v -25v regulated dc out
pin 15 - -92.2v -87.5v raw dc in


pin 16 - -92.2v -65v regulated dc out test pin
pin 17 - 66.5v +65v regulated dc out

:banana::banana: we are on the same page :banana::banana:

The -65v regulator is shorted out, and the -92v it is putting out is making the transistors break down with too high of a voltage - causing the noise.

Since the board can be removed, it is easy to work on. You will soon get a list of capacitors, transistors, goop, mica insulators etc to rebuild the board.

until the power supply is behaving itself, all other readings etc are junk (sorry), so we can not draw inferences from them further.

It would be advisable to keep the unit off until the power supply is fixed. There could be continuing problems with the amps because of the high voltage (25v extra can be bad..) that has been applied. But that is fixable too.

note: the 4 boards (power supply, protection, and two amplifier cards) can be rebuilt externally by someone familiar with them (like me or others) if you care to. I have done it before with good results.heck, I even have spare 1250 boards here...
 
if you don't mind i'd like to try to re-build them myself, just need to know what parts and their #'s. 2 questions, is the bad voltage making my left heatsink heat up and right stay cold? how much would you charge to rebuild all 4 boards if i change my mind?

Edit: sorry about the mix-up earlier, was reading the wrong board once i flipped the receiver over, was reading awm-091's wires, and still was reading them backwards. now i know which board is which and which way to read them, thanks for your patience. i am a fast learner at stuff like this, just takes a few tries sometimes
 
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re- voltage vs heat

maybe, but it could be the amp itself is either set too high (or the other too low) but again even the heat is hard to tell until the power supply is corrected.

as for parts lists, there are several recent 1250 threads with at least capacitor lists, if not the transistors. usually they will be spreadsheets in a zip file.

commercial activity by PM.
 
if you want to and have the time make me a list of parts and #'s for the 2 awh-048's, awm-091, awr-106, awr-107, awg-041 and awg-042 boards to re-build them, needs to be done anyway, and it'll save me on shipping costs. i'll have to wait on the 4 main filter caps.
 
as of November, 2 2010 Checked on mouser.com

Stabilizer Assembly(AWR-106)
647-UPW2A221MHD 220uf, 100v - not available
647-UPW1A101MDH 100uf, 10v - not available
647-UPW1H101MPD 100uf, 50v - not available
647-TVX1E102MCD 1000uf, 25v - not available

Power Amplifier Assembly(AWH-048)
647-UPW2A471MHD 470uf, 100v - not available

Protection Circuit Assemble(AWM-091)
647-UPW1C471MPD 470uf, 16v - not available
647-UPW1H101MPD 100uf, 50v - not available

Flat Amplifier Assembly(AWG-042)
647-UPW1A101MDH 100uf, 16v - not available

Control Amplifier Assembly(AWG-041)
647-UPW1H2R2MDD 2.2uf, 25v(50V) - not available
647-UPW1A101MDH 100uf, 10v - not available

Power Supply Assembly(AWR-107)
647-TVX1E102MCD 470uf, 100v - not available

these are caps only, still gotta find and check transistors, etc. which sucks on dial-up

Will mouser part# 526-NTE87 replace 2sd555, and part# 526-NTE88 replace 2sb600?
 
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all the transistor #'s you supplied without the g were discontinued, EW
and some with the g are going to be discontinued soon :sigh:
 
xXColdShotXx said:
all the transistor #'s you supplied without the g were discontinued, EW
Click to expand...
And we care because...? The numbers with the 'G' are the same transistor, manufactured without the use of lead. I don't think your amp will know the difference. ;) I gave you the base part numbers...figured you could wing the rest. In my last post, I tried to poke you into figuring it out, but I guess that didn't work either.
and some with the g are going to be discontinued soon :sigh:
Click to expand...
I don't know where you got that information, but the four that are most useful for audio power amps (21193~21196) are in full production and liable to stay that way for the foreseeable future.
 
edit
THIS WAS WRITTEN BEFORE YOUR - PICKING ON ME? POST -

IT IS MEANT TO BE CONSTRUCTIVE, BUT I DIDN'T SEE THAT LAST POST UNTIL THIS POST WAS IRREVOCABLE.
END OF EDIT

You have NO idea of the minefield you are running into.

The reason there are SO many SUCCESSFUL DIY fixes on this board is ME, the other knowledgeable folks here are busy working on other people's equipment, and do not spend the tremendous amount of time that hand holding someone through a repair entails, you are left on your own to figure a LOT out - as you are starting to discover, and the helpful learners soon tire of all the typing and 'splainin...

There is NOBODY better on this board for getting their head INTO the head of a rookie and explaining stuff in a way that the rookie can immediately use it. (the fact I had a hard time figuring out your initial posts is probably due to the distraction of both rebuilding a SX-1980's amplifier with modern transistors, while simultaneously working towards political goals that started in the spring, I've been busier than a 9 tailed cat in a room full of rocking chairs)

That said, you are trying to drink from the fire hose - ever see somebody really try to do that? (hint: the Weird Al Yankovitch movie - UHF.. Michael Richards : "Kramer" of "Sienfeld") you get REALLY clean sinuses.

my avatar - the stooges - because sometimes the old repair threads more resembled a stooges routine than a repair attempt. I didn't pick it, someone else did, to describe a particularly harrowing (to me) thread.

The guys and I have a phrase that describes what you are doing " jumping ahead". Part of my skill and reputation is in steering folks AROUND the mines in the minefield that you don't even know are there.

You are FREE to jump ahead, alone - and don't expect me to come to the rescue AFTER you get into a jam.

It HAS HAPPENED, apparently just not recently enough to serve as an object lesson to the newcomers.

Especially when cutting your teeth on a top of the line model that has a LOT of power to make things that go wrong to go horribly wrong.

contemplate this, I would have RATHER spent your time this evening working on the list and not this.

and the FASTEST way to a working unit is to let me lead, and not spend time undoing bad things. You WILL learn a LOT. Perhaps you should be looking up some of the old repair threads on here. The idea is that more than one person benefit from my effort on them.

--------------

That said, I AM on your side, and have built a reputation of doing this well, and I AM working on the list - you CAN speed my process up by posting the lists of transistors in one place - that excellent list of the transistors IN the unit that you did, and the list that has the 512-KSC2073TU_Q on it - so I can see what needs to be changed.

to ansdwer the other question
the awr-106 stabilizer first as it is misbehaving,
the awr-107 board later as it IS still behaving..

BUT we are going to try to order all the parts in one fell swoop.

did you use the bom entry feature to get your november 2 list of out of stock parts at mouser,com??
 
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I may just forget this old piece of crap and throw it in the garbage, can't get a local tech to work on it, he say's "they aren't worth fooling with, parts are too hard to get anymore, and if he did fix it it'd tear up in a week and need something else" and i seem to get attitude from the good techs on these forums. lose/lose situation for me. how do people learn? trial and error. you expected me to take a perfect reading the first time i tried, but i had to figure out how to read the plugs on my own. the sm helped a lil. i had to learn how to read it too for the direction of how to test correctly and board #'s.

Thanks for what help you have given though
 
i looked for thread containing transistor #'s only found a few, and yes i used the bom, which i edited to look like this

647-UPW2A221MHD|2
647-UKT1V470MDD|2
647-UPW1H220MDD|2
647-UPW1H101MPD|2
647-UHE2A470MPD|2
647-TVX1E102MCD|1
647-UKT1A470MDD|3
647-UPW1A220MDD|1
647-UPW1C221MPD|1
647-UPW1C100MDD|2
647-UPW1C221MPD|2
647-UVZ1HR22MDD|2
647-UPW2A471MHD|4
647-UPW1C471MPD|2
647-UPW1E4R7MDD|1
647-UPW1C101MED|1
647-UPW1H101MPD|2
647-UPW1J331MHD|2
647-UPW1C220MDD|4
647-UPW1A101MDH|2
647-UPW1C221MPD|2
647-UPW1V331MPD|2
647-UPW1E4R7MDD|4
647-UPW1H2R2MDD|12
647-UPW1A101MDH|4
647-UPW1C101MED|4
647-UPW1E100MDD|2
647-TVX1E102MCD|2
647-UPW1E471MPD|2

instead of the other way. still has multiples i see, but i will edit it further afterwhile
 
edit this was in response to the 1:06 post, i hadn't even seen the 1:22 post

You have posted before my post was complete, I just read your last post and i suggest you re read all of mine.

as for dumpstering it, that would be a DAMN shame and a significant loss of money, you can recoup most if not all your investment by reselling it, probably to someone local, thus avoiding shipping. Or tell us where the effing dumpster is and somebody else will damn well rescue it. EVEN if it is smashed to hell out of spite.

That tech:
can't get a local tech to work on it, he say's "they aren't worth fooling with, parts are too hard to get anymore, and if he did fix it it'd tear up in a week and need something else"
Click to expand...

has his head up his ASS.

He does know that he would have to put a lot of time and REAL EFFORT into it, and charge for that time to pay the rent & etc...

The 1250 is THE MOST REPAIRABLE of most of the old Pioneers, with easily available inexpensive current manufacture parts.

I among others do restorations of this equipment that we FULLY EXPECT to NOT have back in for repair for 20 to 30 YEARS!!! And to sometimes perform even BETTER than NEW.

On your own efforts, with my STILL OFFERED guidance, you can hit about 90 percent of that - the other 10 percent is not a trade secret, just an acquired set of manual skills for removing, disassembling and reassembling then reinstalling certain components (that were never intended to be disassembled) and polishing away years of wear and tear instead of accidentally destroying those components.

it does take time and patience - and since it is your time - you ain't havin ta pay no tech to do it...
 
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xXColdShotXx said:
i looked for thread containing transistor #'s only found a few, and yes i used the bom, which i edited to look like this

647-UPW2A221MHD|2
647-UKT1V470MDD|2
647-UPW1H220MDD|2
647-UPW1H101MPD|2
647-UHE2A470MPD|2
647-TVX1E102MCD|1
647-UKT1A470MDD|3
647-UPW1A220MDD|1
647-UPW1C221MPD|1
647-UPW1C100MDD|2
647-UPW1C221MPD|2
647-UVZ1HR22MDD|2
647-UPW2A471MHD|4
647-UPW1C471MPD|2
647-UPW1E4R7MDD|1
647-UPW1C101MED|1
647-UPW1H101MPD|2
647-UPW1J331MHD|2
647-UPW1C220MDD|4
647-UPW1A101MDH|2
647-UPW1C221MPD|2
647-UPW1V331MPD|2
647-UPW1E4R7MDD|4
647-UPW1H2R2MDD|12
647-UPW1A101MDH|4
647-UPW1C101MED|4
647-UPW1E100MDD|2
647-TVX1E102MCD|2
647-UPW1E471MPD|2

instead of the other way. still has multiples i see, but i will edit it further afterwhile
Click to expand...

the multiples are intended, that is FINE, and kudo's for getting into the BOM feature solo.
 
all i have in this receiver is a trade of an old studio standard by fisher receiver and $10 to $20, but after i had it for a few years i found out that my grandpa bought this same receicer new back in the 70's and am guessing a set of hpm-100's or hpm-1500's(the ones as big as a fridge?) with it. so it's not only me wanting to piss the neighbor's off with the power of this receiver, but it has been a family heirloom and i hate to have to throw it away cause i can't get it fixed.

wish i had the hpm's to go with this stereo, then it would sound good when/if fixed.
 
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