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My SA - 7100 Drops in and out of Protection

Awesomeaudio; You might want to hit the sticky thread for the PIONEER TUNING FORK series. download them all and read up on capacitors and how they list parameters for them (ie: CEA and CEANL for example). This is directly related to what capacitors are required each place and how and why Mark lists a particular series of capacitor (Usually Nichicon's with a smattering of panasonic's).

Same thing with Transistors. Pin basing between old original and new replacements may change. You'll need to download all the Datasheets for the new ones and compare with the basing of the old ones. For instance an original is set up as an EBC and the new one is an ECB. You will need to swap the B&C pins (turn the transistor 120* and bend the legs some so it'll work. Another instance is the ECB to BCE. Flip the new one 180*. You'll need to know this stuff for every transistor you replace.

You won't be replacing all of the transistors, just bad ones, and problem children (known to cause trouble) as a pre-emptive strike. 2sa725, 2sa726, 2sc1451's are the 3 biggest offenders.

One more thing. On the parts lists for each board in the Service Manual, Each transistor will have a primary transistor and 1 or 2 substitutes listed. The unit may have any of the 2 or 3 at that position. So if you are looking for a 2sa726 and a 2sa763 is in the spot, it's ok. The 763 isn't considered to be a problem child (at least I've never heard it being one).

But replace any 2sa725, 2sa726 and 2sc1451's you find in it, no matter where it is. It'll eventually breakdown and get noisy. It's not an if, it's a when with these 3.


Take it slow and easy. Doing it once and taking 2-3 weeks is easier and CHEAPER than twice @ 3 times the time and $$. Don't get ahead of Mark, he's DAMN GOOD, but like the rest of us mere mortals, he can't read minds or anticipate what you are going to do. Don't work tired, and leave the Barley Malt for AFTER you get done for the day. It makes for BIG Mistakes. And that is costly, both in time and $$.

Have fun, and git'er done!

Larry
 
Awesomeaudio; You might want to hit the sticky thread for the PIONEER TUNING FORK series. download them all and read up on capacitors and how they list parameters for them (ie: CEA and CEANL for example). This is directly related to what capacitors are required each place and how and why Mark lists a particular series of capacitor (Usually Nichicon's with a smattering of panasonic's).

Same thing with Transistors. Pin basing between old original and new replacements may change. You'll need to download all the Datasheets for the new ones and compare with the basing of the old ones. For instance an original is set up as an EBC and the new one is an ECB. You will need to swap the B&C pins (turn the transistor 120* and bend the legs some so it'll work. Another instance is the ECB to BCE. Flip the new one 180*. You'll need to know this stuff for every transistor you replace.

You won't be replacing all of the transistors, just bad ones, and problem children (known to cause trouble) as a pre-emptive strike. 2sa725, 2sa726, 2sc1451's are the 3 biggest offenders.

One more thing. On the parts lists for each board in the Service Manual, Each transistor will have a primary transistor and 1 or 2 substitutes listed. The unit may have any of the 2 or 3 at that position. So if you are looking for a 2sa726 and a 2sa763 is in the spot, it's ok. The 763 isn't considered to be a problem child (at least I've never heard it being one).

But replace any 2sa725, 2sa726 and 2sc1451's you find in it, no matter where it is. It'll eventually breakdown and get noisy. It's not an if, it's a when with these 3.


Take it slow and easy. Doing it once and taking 2-3 weeks is easier and CHEAPER than twice @ 3 times the time and $$. Don't get ahead of Mark, he's DAMN GOOD, but like the rest of us mere mortals, he can't read minds or anticipate what you are going to do. Don't work tired, and leave the Barley Malt for AFTER you get done for the day. It makes for BIG Mistakes. And that is costly, both in time and $$.

Have fun, and git'er done!

Larry

Great insight and advice. I hear what you're saying Larry. I know I have alot of work ahead of me and I will chip away at it slowly.. NO BARLEY MALT either:D
Thanks:thmbsp:
 
The parts list is pretty much complete back (^^^above^^^) there...

and there ARE less than necessary parts in there, like the output transistors (~$16) etc.

about $50 US in there..

I did the 1.5uf caps in UKL because there were no 1.5uf UPW cap values (they are cea type in the service manual).
 
The parts list is pretty much complete back (^^^above^^^) there...

and there ARE less than necessary parts in there, like the output transistors (~$16) etc.

about $50 US in there..

I did the 1.5uf caps in UKL because there were no 1.5uf UPW cap values (they are cea type in the service manual).

Thank you Mark. Your help is appreciated and once I've gathered my thoughts around this and need further help, I'll chime in again.
Just one thing though, can you recommend a decent set of output transistors ?
:thmbsp:
 
bump for what?
:dunno:
the ball is in your court, parts list is complete, overstuffed even, cut and paste mouser parts list entered, while you are in Australia and maybe not ordering from mouser, the data sheets available from mouser for the individual components should help with answers in sourcing parts over there, have a question, ask it....

order parts...
wait for parts..
receive parts...
put parts in... (questions expected here - like how to locate, soldering details, dis assembly and component access details and so forth)
 
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The bump was to keep this thread close, save me searching for it. Lazy I know.
I will come back when I've ordered the parts.
Questions will follow I'm certain.
Cheers
 
Question please.

On the Power amp board AWH-021, there are two varistors on the list that don't have the part number attached, d3 stv-4 and d4 stv-4. Are these necessary to replace and if so, what would the mouser part # be ?
I am in the process of ordering the parts and just need to confirm if I need to add these too before I commit to the order.
Thanks
 
The bump was to keep this thread close, save me searching for it. Lazy I know.
I will come back when I've ordered the parts.
Questions will follow I'm certain.
Cheers

So you don't have to search for this thread, just sign in, click on your name, then statistics, then, threads started by, and then look at the list of threads you've started. Click on this one and your back. :D

I've not seen a replacement for the STV-4's listed. My advise is be very gentle with them. Do not break the leads on these. Work around them with care!

Good luck with your Pioneer, your in great hands!
 
So you don't have to search for this thread, just sign in, click on your name, then statistics, then, threads started by, and then look at the list of threads you've started. Click on this one and your back. :D

I've not seen a replacement for the STV-4's listed. My advise is be very gentle with them. Do not break the leads on these. Work around them with care!

Good luck with your Pioneer, your in great hands!

Thanks for the tip friend. Will do.:thmbsp:
 
they are not replaced, and are treated VERY gently - NOT bending the wires AT ALL within 1/4 inch of the component body - they LOVE to break off FLUSH, THEN I have to try to recover them, (excavating, soldering on new flexible leads, epoxying additional body onto it) not a fun, nor an EASY task. I have developed the skill but prefer not to have to use it.
 
I can't stress this enough! Don't mess with them. They keep the bias from going ballistic and are rare as hens teeth. Just meter them in the ohms position. If they ohm out good leave them alone. They are no longer made and there are no replacement parts for them. If you break the lead off, you can probably get Mark the fixer to repair it. He's got a jig to repair them. Replacements will have to come from a donor amp/receiver.

Larry
 
I can't stress this enough! Don't mess with them. They keep the bias from going ballistic and are rare as hens teeth. Just meter them in the ohms position. If they ohm out good leave them alone. They are no longer made and there are no replacement parts for them. If you break the lead off, you can probably get Mark the fixer to repair it. He's got a jig to repair them. Replacements will have to come from a donor amp/receiver.

Larry

hopefully it will be the one you broke...
 
they are not replaced, and are treated VERY gently - NOT bending the wires AT ALL within 1/4 inch of the component body - they LOVE to break off FLUSH, THEN I have to try to recover them, (excavating, soldering on new flexible leads, epoxying additional body onto it) not a fun, nor an EASY task. I have developed the skill but prefer not to have to use it.

I thought I'd do a quick measure of these and post back the results.
Are these values what you expected ?
 

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A measurement from an ohmmeter is pretty useless. Diode test, out-of-circuit, is what tells the tale. But, these are tough devices and rarely fail...except when the wires break.
 
I thought I'd do a quick measure of these and post back the results.
Are these values what you expected ?

I would not remove them even just to test too high risk, just recap that board and replace the transistors and you should be good to go for the amp board.
 
when moving the heat sinks, loosen the screws holding the diode and slip them out and DO NOT bend the last 1/4 inch of wire by the component.
 
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