Have a look here...
And here
You'll be lucky.
Sansui AU-X901, replacing power transistors, 2SC3519 / 2SA1386, options?
- Thread starter Magnus Back
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And here
I got the new TA7317P and it's not real. Will send back.
I tested the original and it's definitely broken. 24 Ohm between pin 1&2 and short circuit between 2,3,4, 7 etc with a transistor tester.
"There should be a resistance of 1.0k between pins#1 & 4. Between pins #2 and 3 to 4 there should be antiparallel diodes."
So where to get a real one?
I tested the original and it's definitely broken. 24 Ohm between pin 1&2 and short circuit between 2,3,4, 7 etc with a transistor tester.
"There should be a resistance of 1.0k between pins#1 & 4. Between pins #2 and 3 to 4 there should be antiparallel diodes."
So where to get a real one?
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Sui-Yogi
Super Member
On the other side of the globe but what ever I have bought from him it was original .
If you go for it , write him first that you need the original . If he says okay , then it will be okay .
No affiliations, just a happy customer:
If you go for it , write him first that you need the original . If he says okay , then it will be okay .
No affiliations, just a happy customer:
ElectTech
Active Member
Hello, I did those tests in those diagrams. You should do a 'diode test' between the pins as shown in the table, if not already done.
The TA7317P that I tested in those two clips was purchased in 2018 on eBay from Seller: tube_buyer
Shipped from California. I bought a few from that Seller. All ICs tested OK per the table above. If they are 100% legit, I can't assure that, but they worked in my tests.
TA7317P IC issues
I've been away for a long time this summer and haven't had time but just got back last night.
With a healthy amount of jet lag I installed it, still doesn't work.
Will have to test more and see what else is still wrong here.
With a healthy amount of jet lag I installed it, still doesn't work.
Will have to test more and see what else is still wrong here.
The old TA7317P is definitely broken, short between a few legs.
The new TA7317P measure good according to the diode test above and follows the schematic.
I now have about 0mV on every pin of it ...
Found kR102L, lD8 broken.
Last item I discovered was a bad trace connection by mD5. It looks connected but wasn't. The trace was broken in a circle round the solder.
More testing tomorrow.
The new TA7317P measure good according to the diode test above and follows the schematic.
I now have about 0mV on every pin of it ...
Found kR102L, lD8 broken.
Last item I discovered was a bad trace connection by mD5. It looks connected but wasn't. The trace was broken in a circle round the solder.
More testing tomorrow.
Gremlins. Grounding, found one bad connection and now at least I have sane voltages on the board. Now why is pin 5 23V?
1 0.7 V
2 50 mV
3 10 mV
4 0 V
5 23 V <---- issue
6 15-20 mV
7 0 V
8 32 mV
9 3.11 V
Shorting pin 7 to GND does not make it click (but it already is zero). Maybe the relay rL3 is bad?
1 0.7 V
2 50 mV
3 10 mV
4 0 V
5 23 V <---- issue
6 15-20 mV
7 0 V
8 32 mV
9 3.11 V
Shorting pin 7 to GND does not make it click (but it already is zero). Maybe the relay rL3 is bad?
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Is this pin 5 on the TA-7317P IC?
Pin 5 of the above IC goes via a 10K resistor (R19) to the smoothed (but not regulated) -38V supply.
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Yes, which is why it's odd it's a high positive voltage. This is supposed to be the internal equivalent layout of the IC.
No I tested that one, and almost every component on the board, yesterday.
The main issue is probably that pin 6 is low voltage.
It should go from ballpark 13V down to 1.4V when the relay clicks.
It should go from ballpark 13V down to 1.4V when the relay clicks.
The transistors associated with Pin 6 are the relay driver transistors, obviously important in a protection circuit that this works as it should.
The power feed (~25V DC) to those relays comes through the speaker selection switch(es) S8a & S8b - has this been checked?
That protection circuit diagram is bloody complicated.
The power feed (~25V DC) to those relays comes through the speaker selection switch(es) S8a & S8b - has this been checked?
That protection circuit diagram is bloody complicated.
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I replaced all the transistors because they were broken. I'll check again.The transistors associated with Pin 6 are the relay driver transistors, obviously important in a protection circuit that this works as it should.
The power feed (~25V DC) to those relays comes through the speaker selection switch(es) S8a & S8b - has this been checked?
That protection circuit diagram is bloody complicated.
Good idea to check switches as well.
When I say 'relay driver transistors', I mean the ones inside the TA-7317P IC, Q12 & Q13. Normally they are separate/discrete but this IC does it all.
Yup for a while I thought mQ1/mQ2 was driving, looking at another amp using this chip but I misread the schematic.When I say 'relay driver transistors', I mean the ones inside the TA-7317P IC, Q12 & Q13. Normally they are separate/discrete but this IC does it all.
If it is the transistors in the IC, which is "new" then I really don't know what to do here. Find another one ... ?
Tested switches, retested DC offsets and bias, checked the few remaining components on the board and nothing.
Not easy to rig it to always drive the relay either as there now are no driver transistors for it.
I could use the voltage on pin 5 but unsure if that's safe.
Not easy to rig it to always drive the relay either as there now are no driver transistors for it.
I could use the voltage on pin 5 but unsure if that's safe.