i did it, i checked each and every pin for shorts and cold solders, there were 2 shorts at mje340 and 15032, i cleared them, still the problem persists.
Check the pics and guide.
Attachments
Grounding
I can't see input ground to PSU did you follow this?
I can't see input ground to PSU did you follow this?
Attachments
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Hi..Viki.. I see your B500..that original resistor 47K (red code), but applied 4K7..is wrong..this picture:
The sound is very low and distorted.
The resistor 0r22/5w in front of 2sa1943 on psu board got burnt .
My psu 24-0-24 before rectification, after rectification 37-0-37.
Yes i followed the diagram. connected the psu gnd , input gnd and out gnd at a common point on gnd next to out
voltage on negative terminal drops to 20v, after connection to b500.
positive voltage is proper at 37v.
positive voltage is proper at 37v.
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Hi Apex. i have a problem with your amplifier.
It all looks ok when connect him, and play song. But when volume reachs half, speaker starts broming(brrrrrrrr) very loudly. I turn off amplifier, reduce volume and and turn again on, and all looks again ok. Where is the problem? Please help me!!!!!!!
It all looks ok when connect him, and play song. But when volume reachs half, speaker starts broming(brrrrrrrr) very loudly. I turn off amplifier, reduce volume and and turn again on, and all looks again ok. Where is the problem? Please help me!!!!!!!
could it be Low Frequency instability of the PSU to amplifier interaction? Used to be known as "motorboating" in valve amplifiers, because that is what it sounded like.
did you test MJE340/350 and 2n5551,5401 unmount it on the pcb then test it with multimeter
I tested them, seem to be ok.
I changed 5401 near -90v . The problem of voltage drop is solved. Equal voltages on both terminals.
Psu is also stable and fine no burning , no heating of any parts.
Still no sound.
No current on out.
I changed 5401 near -90v . The problem of voltage drop is solved. Equal voltages on both terminals.
Psu is also stable and fine no burning , no heating of any parts.
Still no sound.
No current on out.
I think you mean 33E = 33r = 33ohm resistor.
If that is the case, then E33=0r33 = zero point three three ohm resistor.
Do not drop the leading zero. It is important to accurate transfer of information.