transistor amp not working after shorting output

[sg97]

output voltage is 16v ? is it normal ???????

 

[sg97]

maybe in this state is 16v i am not sure

 

[sg97]

hahah i did not measure right sry guys it is 55v dc xddd

 

[sg97]

also small transistors are not warm at all so thats good i think btw if i reduce input volume jsut right sound is small but clear

 

[sg97]

question is when i replace two resistors that are needed. should i connect both 2n3055 at once or one by one t osee how it works ?

 

[oscroft]

also small transistors are not warm at all so thats good i think btw if i reduce input volume jsut right sound is small but clear

Great result so far - and 55v at the power supply cap sounds good.

 

[Netlist]

question is when i replace two resistors that are needed. should i connect both 2n3055 at once or one by one t osee how it works ?

Connect both. Make sure you solder the correct wire to the correct pins. Third wire goes to the metal L-profiles.
Again test first with a bulb. If all is well, you should have enough power for a small party.
After that you can leave out the bulb circuit.

 

[sg97]

could it be that only two resistors are makin a problem ?

 

[sg97]

sadly i have to wait for resistors to arrive i dont have a replacement rn 😀 i cant wait to try it out xdd

 

[sg97]

btw i wonder what is the real purpose for those resistors ? transistors cant work without them ? how it works, i only know that wone is connected to one of the transistors

 

[Netlist]

My guess has always been that these are emitter resistors. Its' very difficult to see from the pictures.
Anyway, they are there for a reason. They only way to know if they are bad is to desolder the coil around them and to measure their resistance.

 

[gijser]

If they are indeed emitter resistors, they are there to stabilize the idle current through the output transistors. If you would bypass them, you would have to reset the idle current, and you would have the risk of thermal runaway and destruction of the output transistors. So, better be patient 😉

 

[sg97]

they look burned also i remember when it broke that wire was glowing so thats that xdd

 

[Netlist]

Take them out, they have to go anyway.
Maybe one of them is still good so it could be measured.
You could try to find out the colour code. I would think that one of them is not too badly burned.

 

[oscroft]

Yep, I'd guess at emitter resistors too. If so, they play a very important part.

I agree, don't put the big transistors in and power it up until you get replacement resistors in - if you do, you might risk hot, hot, burn, bang, smoke 😉

 

[sg97]

Take them out, they have to go anyway.
Maybe one of them is still good so it could be measured.
You could try to find out the colour code. I would think that one of them is not too badly burned.

i will try it but if my theory is that resistors burned and only wire was left so it was glowing like bulb xddd

 

[sg97]

i will not connect big ones without resistors. i am not that stupid xddd i hope when i add it that it would work normally.

 

[sg97]

btw for ones that are interested xdd here are what are those resistors. one on right was 2.7M Ohms 1% second one is too burned to read the colors. wires dont measure anything, resistors measure like sometimes 300k sometimes 600 or more i am not sure why

 

[Netlist]

one on right was 2.7M Ohms 1%

Is that the colour code? That would be Red - Violet - Green / Tolerance 1% = Brown.

 

[sg97]

other one i cant tell but this one is like that