transistor amp not working after shorting output

[sg97]

thats ok i can find it for parts you sent me or any other that i can find new, my issue is i dont know c b e locations on board here from top view.

 

[sg97]

when i will install those small transistors i will do it from the top of course so thats why i ask for this, so i can know exact c b and e places where legs go.

 

[anatech]

Okay, with your meter ...

You will measure a diode drop from the base to each emitter and collector. The polarity depends on the part being NPN or PNP. The base is positive on NPN. hFE test, one way (swapping emitter and collector) the beta will be much lower than the other. When you have the high beta reading, that is correct.

 

[Netlist]

There was a little drawing I made from the pinout of each transistor.
I guess you found that.
Look at that, one transistor at a time an find the holes on the board that correspond with E B C.
First there's the small black one, then two BD139 and one BD140.
Try, I'm sure you'll find out, it's really not that hard.

Hugo

 

[sg97]

i will look to all pictures i have from you guys and i will find xd, also before powering up i will send a picture so you can check 😀

 

[Netlist]

Take the old ones out and stick the new ones in without soldering them and we'll check.

Hugo

 

[sg97]

good idea 😀

 

[sg97]

i did this, by looking at old transistors and new ones i made a guess that it should go like this, correct me freely if i made a mistake 😀 btw its not soldered

 

[sg97]

here is board without transistors so if someone wants to correct me here is best solution 😀

 

[Netlist]

Post a picture of that little note that came with the parts so others can follow.
Now, have a look at it and compare to your markings.
What do you see?

Hugo

 

[sg97]

thats ok but i cant do it 100% there are no markings of any kind on old transistors so i cant really do it. i am sorry but i just cant, this is what i assumed it was like and that was all i can do

 

[sg97]

btw i assumed that case of old transistors are collectors maybe not i am not sure

 

[Netlist]

Don't think of the old transistors anymore.
Follow my paper to find B C E
I marked B C E on the lower part of the picture for all four transistors.
Hope this helps.

 

[sg97]

i can use this picture but for one 149 if you remember old transistor was mounted like this, that confused me btw from your note i can see b c e for the transistors you sent so i can put them in place now with this info

 

[sg97]

that 140 is my issue

 

[sg97]

i have to bend pins like in old one to get same result, i dont like it but its only way

 

[Netlist]

Make sure the legs don't touch each other.

 

[sg97]

i think i got it right this time 😀

 

[sg97]

i was using this as reference, 139 and 140 are same pinout as written in note, btw 184 i should just put in place where old was ? it should have same orientation

 

[Netlist]

Are these the front of each transistors?
If yes, it looks OK.

I don't know what small transistor was in there, but I said forget the old transistors, only follow the pinout in the note.