0r33 not or33
Zero point three three.
That Zero is important. do not call it o nor O get used to Zero, that is quite different.
Notice I did not say Zero point thirty three. never join the digits after the decimal point. Always read them out separately. Only the digits before the decimal point are allowed to joined. 124 becomes one hundred and twenty four, but 0.33 never becomes: point thirty three.
Zero point three three.
That Zero is important. do not call it o nor O get used to Zero, that is quite different.
Notice I did not say Zero point thirty three. never join the digits after the decimal point. Always read them out separately. Only the digits before the decimal point are allowed to joined. 124 becomes one hundred and twenty four, but 0.33 never becomes: point thirty three.
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please help, anyone? r20 and r21 getting burned
Sir Apex, I have a problem with this B500, as soon as I switch on the circuit, the 100R resistor (R20,R21) is getting burned:
this are the specs of the circuit taken from the forum and schematics:
psu: +/- 68Vdc
transistors: 1943&5200, mje340/350,2n5401,2n5551, zeners 15Volts 1 watt, R24/25 2.2K 2watts. I attached some pictures for everyone to give me some advice, tanx in advance for any help u can give.nsl32 replace by red LED and 47K resistor.
Regards,
mj777
Sir Apex, I have a problem with this B500, as soon as I switch on the circuit, the 100R resistor (R20,R21) is getting burned:
this are the specs of the circuit taken from the forum and schematics:
psu: +/- 68Vdc
transistors: 1943&5200, mje340/350,2n5401,2n5551, zeners 15Volts 1 watt, R24/25 2.2K 2watts. I attached some pictures for everyone to give me some advice, tanx in advance for any help u can give.nsl32 replace by red LED and 47K resistor.
Regards,
mj777
fake transistors
hi mj777
greetings i had the same problem CHECK PIN COONNECTIONS OF
2N5401 2N5551 lots of fake transistors around same make BASE PIN was at side
not middle in some base pin was in centre both transistors had these 2n5401 2n5551 HOPE this helps you out
thanking you
andrew lebon
hi mj777
greetings i had the same problem CHECK PIN COONNECTIONS OF
2N5401 2N5551 lots of fake transistors around same make BASE PIN was at side
not middle in some base pin was in centre both transistors had these 2n5401 2n5551 HOPE this helps you out
thanking you
andrew lebon
Sorry but if it isnt zero. thirty three, what will it be.
i purchased . thirty three ohm resistor for b500.
please guide.
dear andrewlebon,
i have tried to check the transistors and all seems to be working fine, to verify that it is working(the transistors) I fixed it on my other diy amp the dx blame mk2 prototype and it is working fine. so i think the problem is not in the transistors, any other ideas u can share? and in ur nsl 32 replacement what is the resistance value of the ldr u use?
regards,
mj777
i have tried to check the transistors and all seems to be working fine, to verify that it is working(the transistors) I fixed it on my other diy amp the dx blame mk2 prototype and it is working fine. so i think the problem is not in the transistors, any other ideas u can share? and in ur nsl 32 replacement what is the resistance value of the ldr u use?
regards,
mj777
check the post
http://www.diyaudio.com/forums/solid-state/164208-500w-pa-amplifier-limiter-139.html#post2513039
check your inbox tol may pm ako sayo 😀
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Hello,
Solved the problem of 22e Resistor Burning on psu board.
I disconnected the middle pin of Transistor MJE 15033. Earlier the volume was very low, After disconnecting the middle leg it is very loud , very very loud, But very distorted.
It seems 15033 having wrong pin orientation.
Voltage on output varies between 9 to 11 mv.
What should i do next ?.
Solved the problem of 22e Resistor Burning on psu board.
I disconnected the middle pin of Transistor MJE 15033. Earlier the volume was very low, After disconnecting the middle leg it is very loud , very very loud, But very distorted.
It seems 15033 having wrong pin orientation.
Voltage on output varies between 9 to 11 mv.
What should i do next ?.
Attachments
all To126 and To220 BJTs have the collector in the middle.
You cannot have the wrong pin orientation.
Have you inserted it back to front?
You cannot have the wrong pin orientation.
Have you inserted it back to front?
No i have not, But when checked with a multimeter red leg connected to 1st leg of 15032 second and third leg give proper reading,
But with 15033 when connected in same manner no reading.
When Black leg of multimeter connected to 1st leg of 15033 second and third leg give proper reading
But with 15033 when connected in same manner no reading.
When Black leg of multimeter connected to 1st leg of 15033 second and third leg give proper reading
three possibilities.
you buggered them.
you bought rip offs.
you can't use your test instruments.
you buggered them.
you bought rip offs.
you can't use your test instruments.
Didn't understand buggered, as i checked 5 transistors
No rip offs , got them as sample from on semi.
This is possible, Many things i have learned recently
.
Hi Viki,
Its normal !🙂15032 is NPN so 1st pin base is positive. with red lead in base and black lead in 2 and 3 collector and emitter will show readings.
where as 15033 is a PNP so 1st pin base is Negative. with red lead it wont conduct; only with black lead at base(1 pin) will give readings😉 respective to collector and emmitter
your tansistors or absolutely Ok.😀
hi viki,
recheck your work 3 times or more, component value & placement..then try to insulate or clip the 1/8 bolts of mje15032/33 maybe this conduct short circuit...then clean up your board with acetone or thinner.
regards,
nix
I agree with NIX better check your work many DIYER's and me have made this amp with out problem...maybe you have little glitch on placement of the parts mje 340/350,15032/33 are tricky you have to be more careful
MJE350 is PNP
MJE340 is NPN
MJE15032 NPN
MJE15033 PNP
if its original
if fake you got wrong orientation of pins
MJE350 is PNP
MJE340 is NPN
MJE15032 NPN
MJE15033 PNP
if its original
if fake you got wrong orientation of pins
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