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Pioneer SA-9100 electric checkup walkthrough

You'll need to methodically do an intense visual assessment of all of the boards and components for damage or improper installation. Then methodically check specific voltage points to isolate what circuit your problem or problems lie. MTF may chime in here to hopefully reign you in and get you back on track.
 
Yeah i guess that was, what was ahead.
I saw that my bulb tester (which i made last night in a hurry) was made wrong.
Quite stupid mistake! but just to give some useful information:
- The bulbs blew when it was equipped without a dim bulb tester.
- power was taken from the unit.
- The shorting screw was removed
- the unit (without bulbs) was put on a dim bulb tester;
- the dim bulb tester worked as a charm; the bulb lighted and fainted as it should. but the relay didn't kick in.

That is the place i am currently standing, i think about replacing the bulbs to see if that makes the machine's relay kick in (i have an idea that the protector lamp is preventing the relay to kick in)
At least i now have a working dim bulb tester!
I am mostly worried for the output transistors, i could check these out of circuit?

Best regards
Soren
 
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I checked the offset, to see what made the relay klick in - 20Volt on each channel(!!!)
It is turned off now, i really need help to go about this!

best regards
Soren
 
Start at the beginning, check that the power supply voltages are correct...

because the same fault on BOTH channels indicates there is a common cause.

That ONLY leaves the power supply.
 
power supply voltages:

pin1: 0.00v
pin2: -12.92v
pin3: -21.5v
pin4: -13.4v
pin5: -38,4v
pin6: -40.4v
pin7: 40.1v
pin8: 38.6v
pin9: 31.4v
pin10: 18.1v
pin11: 04.7v

I hope you can make something out of this!

best regards
Soren
 
When i replaced the transistors on the power supply, I replaced
the 2sc1318 with the KSA1220AYS and 2sa720 with KSC2690AY.
Was that maybe a mistake?

best regards
Soren
 
Hi (amp)santashooter, :D

santashooter said:
I replaced the 2sc1318 with the KSA1220AYS and 2sa720 with KSC2690AY. Was that maybe a mistake?
Click to expand...

ooof. You bet!!! You sure did that?
-> SCxxx or SDxxx is NPN-Type, SAxxx or SBxxx is PNP-Type!!

Disregarding what else happened. You put in PNP where NPN is due and vice versa. Couldn't possibly expect that to work.
'Maybe' :yes: you should read: http://www.audiokarma.org/forums/showthread.php?t=43186 post #1 (basic transistor knowledge supplied by EchoWars)
AND post #11 (basic transistor configuration knowledge supplied by MTF).

Didn't you already?

Greetings from your southly neighbour,
Frank
 
Ahh! i guess that was where it was wrong, I guess i just thought that MTF listed the transistors in the order in which it should be replaced:
markthefixer said:
the 2sc1318 and 2sa720 transistors in the power supply with to-126 cased transistors for better heat dissipation
512-KSA1220AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.39 (R=60-120, O=100/200, Y=160/320)
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40
Click to expand...
I guess i took this too lightly - could i just replace the two transisters (i did get spares) and then hope nothing else in the amp suffered from this blooper?

I do know about transistors and their different types, i just didn't think about them going the other way... Damn it!

best regards
Soren
 
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I would like to get some useful guidelines as to what I could do?
I really want to spend everything on undoing this horrible mistake.

Best Regards
Soren
 
Hi Soren,

See if I summarize correctly what happened:
Post #17: you prooved the power supply to be fine.
Thereafter you made/found 2 mistakes:
1. You possibly caused continuity between collector and heatsink of an output transistor after applying new thermal cote.
2. You replaced 2 transistors on power supply as precautionary measures, but unfortunately you mixed them.
3. You turned it on on DBT and somethings blew.

You asked if you should test an output transistor 'somehow' (post #21). Then you said (post #29) you know about transistor.

Here's what I would do:
What about reading Glenn's (Echowars) post on basic tansistor knowledge now? There is (among other useful information) described how to test transistors. I would test the output transistors.
Second I would restore power supply. Here others with more knowledge may help which components may have been damaged there. Restore the condition you've had before post #17.
Save the unit! :thmbsp:

Frank
 
I have read glenn's post again, and i tested the output transistors, they are all gone.
I need to find some new ones, preferably ON-semi.
But they are not going in, before someone with more knowledge thinks it is safe, and I will wait with ordering until I know if anything else should be in the order.
I will restore the powersupply - anyone have any ideas to what I need to replace?
Or hints to where i could start?

best regard
Soren
 
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santashooter said:
I have read glenn's post again, and i tested the output transistors, they are all gone.
I need to find some new ones, preferably ON-semi.
But they are not going in, before someone with more knowledge thinks it is safe, and I will wait with ordering until I know if anything else should be in the order.
I will restore the powersupply - anyone have any ideas to what I need to replace?
Or hints to where i could start?

best regard
Soren
Click to expand...

Do the 6 way diode test on the two you swapped, they might have survived in those positions. if they did, insert them in the correct places and test the voltages:Bipolar Junction Transistor Testing Basics


TO-3 output transistors (the oval ones with two pins out of the bottom and two mounting screw holes ):
863-MJ21193G pnp to-3 250v 16/30A 250W 8-75hfe 4mhz $4.56
863-MJ21194G npn to-3 250v 16/30A 250W 8-75hfe 4mhz $4.23

BEFORE installing the output transistors, insulate the empty sockets and turn on the amp, measure the voltages at amp board pins:
12 (0.000v)

15 (0.000v)
16 (-45v)
17 (-0.600v)

18 (0.000v)
19 (+45v)
20 (+0.600v)

the pin 17 and pin 20 voltages should vary slightly as you adjust the VR2 idle current setting.

Pins 12, 15 and 18 will be at the offset voltage and you CAN adjust the offset voltage to zero using VR1.


Only if these voltages and yours are about the same can you then install the output transistors.
 
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Hi everybody - I chose to deliver my amp to a friend of mine, who is a skilled technician - and she is now completely redone by him - he does a fantastic piece of work, and this time was no exception.
My baby is back, and I know she is healthy now.
Thank you for your help so far - It will take some time before i will dive into the deep end again - thank you!

Best Regards
Soren Iversen
 
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