Pioneer SX-2300 audio output problem

Pioneer Amplifier SX-2300

My stereo amplifier turns on but there is no sound output to the speakers and the headphones
Here’s what happen my brother decided to ad or connect another speaker on the B side
of amplifiers speaker output the A side output ad two speakers on it already as soon he
Connected the extra speaker bang no more sound of course he overloaded ohms capacity
Of the amplifier I know that you can connect as many speakers you want as long you respect
Te ohms capability that the receiver can handle
This receiver is rated (A or B 6 to 16 ohms ) ( A+B 12 to 32 ohms )
and with surround sound on 8 to 16 ohms
So my question where should I start to check or what parts could of gone bad

Direct link = http://s24.postimg.org/ada1t1sud/Pio..._MB_front2.jpg
Attachment 18766


direct link= http://s24.postimg.org/gghz23net/Pio...0_MB_back2.jpg
Attachment 18767

Only one speaker on the "B" side??? not a good idea.


He more then likley blew one or both of the output amps, or the drivers for the amps, I can't tell by the photos but do you see anything that looks like an output fuse of and internal fuse?

They would look like a little green resistor if they used one.

here is a link to a service manual for that one.

Code:

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http://www.kallhovde.com/pioneer/tricomp/Audio/SX/SX-1300_2300_ARP1477.pdf

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Terryl do you mean this on the pic

direct link= http://s17.postimg.org/6w81jh2tb/IMG_20130628_00035.jpg

Attachment 18772

No it should be on the main PCB, if they have some on there, or they could be external fuses, in a fuse holder.

They might not use them, the large transistors located on the back of the receiver are the power amps, then just before them are the pre-amps, they look like the main ones but do not have a heat sink on them..

But sence you do not have any audio on "A" "B" or the headphones the output IC could have been damaged, if that is the case and there are no fuses then it's time for a new one.

ok skywalker this ones going to take a little time. i did not have much time to look at this just yet will look at it more later. like before you just want to see if you can do it right.

one thing we will need to start getting are part numbers off the chips like the big ones mounted on the back i will look at the schematic to see where is what.

terry thanks for the link great. i saw in the parts list there 4 fuses.

Thanks nunoit and you are correct know the big transistor chips number are there is two C3180N 0.9E and two green ones A1264N 0.8A and the four small ones two black and two green C2238 0.8A and A968 0.8A what's the correct way to test these
and Terryl here is a pic of the four transistors
Attachment 18777

After going over the parts list and schematic (what there is of one), I don't see an on board fuse for the audio.

So this means that ether the drivers are gone, or the finals are gone, (or they all have gone) you can contact Pioneer to see if they are still available.

I did find a like receiver on E-bay, you might want your brother to fork over the cash and get another one.

Code:

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http://www.ebay.com/ctg/Pioneer-SX-2300-2-Channel-120-Watt-Receiver-/114211004

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When he hooked up the "B" side to the speaker, did he use two speakers (L&R) or just one connected across L&R?

Terryl he only connected one to the right side and thanks for the link I will check it out

before we go to far when plugged in when you power up do you get any thing at all. lights, radio display, tuner changing channels any thing. we could be looking in the wrong place to begin with. you don't need speakers connected at this time just minimize volume control for test.

with that said !!

sky those are npn and pnp transistors. think of them like to diodes in one package. you can use diode test function and test from base (b) to emitter (e) and base (b) to collector (c) then collector (c) to emitter (e) on board. if you get funny reading remove and test. (explained later)

ok when you look at them from mounting side left to right b c e (i posted a pic)

you have complementary pair pnp next to npn sorta matched black one with green one side of amp. the bigger the transistor the more power it can handle.

for a npn device
you connect red lead to (b) black to (e) take reading log it

then leave red on (b) move black to (c) take reading.

then put red on (e) leave black on (c) take reading

reverse leads and repeat tests above

for pnp device reverse leads and test like npn device.

if any read shorted or open device is most likely bad.

you could also remove it and use transistor function on tester to see if it is good. put leads in respective holes on tester.

pnp = positive negative positive.
npn = negative positive negative.

First the amp turns on just fine all the buttons on the front panel are working correctly
Tuner tunes in or on to right radio stations but no sound I have notice one thing do
The resistors on the small board where the speakers connect they are giving me nothing
don’t know if that’s important and now here is the results that I have taken from the four
Transistors connected to the heat sink



transistor 1 C3180
0.123 b-e
0.494 b-c
0.513 e-c

0.123 e-b
0.689 c-b
0.769 c-e

transistor 2 A1264
0.123 b-e
0.123 e-b
1.087 b-c
0.488 c-b
0.519 c-e
1.150 e-c

transistor 3 A1264
0.122 b-e
0.123 e-b
1.632 b-c
0.485 c-b
0.521 c-e
1.552 e-c

transistor 4 C3180
0.123 b-e
0.123 e-b
0.494 b-c
0.679 c-e
0.533 e-c

those resistors should give you some kind of reading real low ohms i see 2.7 and 4.7 ohms worst case they might read shorted not open. if you get no reading at all i would think they are bad. just a note those look like wire wound power resistors (could be carbon). according to parts list r856, r857 are rs2lmf100j i am going to guess 4.7 ohm 1 watt and r854, r855 are rs3lmf2r7j 2.7 ohm 2 watt j indicates 5 %. i tried looking up those part numbers and got nil.

by the way the reading you got look confusing. b-e e-b should be different and b-c, c-b, e-c, c-e should show directional flow difference. now there is that big white dual resistor causing back feedback and according to schematic r527, r528, r537,and r538 also. so it is possible they are good the way to find out better would be to pull and test with tester. unless you had an in circuit tester. but lets not go there. if you want pull one and try your tester. i think they are good not 100% certain.

nunoit this is how did the test and that's the results i get

transistor 1 C3180
0.123 (+ red on b 1)-(e 3 - black )
0.494 (+ red on b 1)-(c 2 - black)
0.513 (+ red on e 3)-(c 2 - black)

0.123 (- black on e3)-(b 1 + red)
0.689 (- black on c 2)-(b 1 + red)
0.769 (- black on c 2)-(e 3 + red)

now for the resistors those are two resistors 2.7 ohms 3 watts one 10 ohms 2 watts and one 4.7 ohms 2 watts they all end with (J) i guess +5%
I'm going to remove one transistor and checked again and see if I get different results

the only reason i am concerned with the readings is the b to e, e to b reading is the same which indicates bad, but like i pointed out there are resistors connected between those pins that could be why you read .123 both ways the other readings you are getting are the sign they are good.

did you get readings from those resistors. i did not see the 10 ohm unit in the pic.


also check out all the other transistors in that blocked out area. marked power amp. we will also be looking at the pre-amp section after we finish with this section. from what i see in the schematic there are 20 transistors in total to check 10 for each side.

if you look at the schematic section 5 block area c & d, 4 & 5. you will see all the components you need to find and test.

ok nunoit I removed all four transistors and these are the readings I get

Transistor1
C3181N R.8A

red on pin (1) black on pin (3) =.546
black on pin (1) red on pin (3) = OL
red on pin (1) black on pin (2) =.543
black on pin (1) red on pin (2) = OL
red on pin (2) black on pin (3) = OL
black on pin (2) red on pin (3) = OL

Transistor 2
A1264N R.8A

red on pin (1) black on pin (3) = OL
black on pin (1) red on pin (3) =.531
red on pin (1) black on pin (2) = OL
black on pin (1) red on pin (2) =.523
red on pin (2) black on pin (3) = OL
black on pin (2) red on pin (3) = OL

Transistor3
A1264N R.8A

red on pin (1) black on pin (3) = OL
black on pin (1) red on pin (3) =.519
red on pin (1) black on pin (2) = OL
black on pin (1) red on pin (2) =.511
red on pin (2) black on pin (3) = OL
black on pin (2) red on pin (3) = OL

Transistor4
C3180N R.8A

red on pin (1) black on pin (3) =.526
black on pin (1) red on pin (3) = OL
red on pin (1) black on pin (2) =.515
black on pin (1) red on pin (2) = OL
red on pin (2) black on pin (3) = OL
black on pin (2) red on pin (3) = OL

and yes there is a 10 ohm resistor there and what is the best settings on voltmeter mine goes from 2k to 200k i removed one and the best result i get .0003

Unless your doing this as a hobby lets face it the pioneer sx-2300 is a 2 channel stereo receiver that about 20 yrs old now and was a dog at best.You can buy a used 7.1 audio receiver almost anywhere these days for about $50 but like i said if its a hobby good luck and have fun,if not move on to something else.