Hello. I want to but an Audison VR 209. He said that the amp starts, the green led is on, the red is off that indicates that it's not in protection mode, but it doesn't make any sound.
It's a amplifier in A/B class wich is capable of 365W in 4 ohms or 2x 110w/4ohm. The prefinals are BD140 and 139.
What can cause this kind of problems? Please help me a little bit.
It's a amplifier in A/B class wich is capable of 365W in 4 ohms or 2x 110w/4ohm. The prefinals are BD140 and 139.
What can cause this kind of problems? Please help me a little bit.
Today i've received the packet. First time i put the power and the wires stared to melt... After that i tried to disasamble the board and i've found that the amp was repaired.... But the traces on the power suplly part was treated very bad! Aftfer i found the "short" i mean solder between traces i've put it on 12V and the green led is on, but no sound! I've found another cap between power B+ lines that was mecanical distroyed and i've removed, it's a 100nF cap....
I measured the voltage between rails and i have +/- 3.5V... That's no good!
https://picasaweb.google.com/115991106712336811055/January242012#5701201008279103506
https://picasaweb.google.com/115991106712336811055/January242012#5701200987157445074https://picasaweb.google.com/115991106712336811055/January242012#5701201046590322994
https://picasaweb.google.com/115991106712336811055/January242012#5701201038732953746
The gate resistors are ok, not burned! The pot for muting was good, but i've already replaced temporarly. Any ideeas?
What i need to check first time?
I measured the voltage between rails and i have +/- 3.5V... That's no good!
https://picasaweb.google.com/115991106712336811055/January242012#5701201008279103506
https://picasaweb.google.com/115991106712336811055/January242012#5701200987157445074https://picasaweb.google.com/115991106712336811055/January242012#5701201046590322994
https://picasaweb.google.com/115991106712336811055/January242012#5701201038732953746
The gate resistors are ok, not burned! The pot for muting was good, but i've already replaced temporarly. Any ideeas?
What i need to check first time?
Attachments
On a inspecion i saw that on zone of the mute pot are 2 transistors one BC327 and BC337. One of them was replaced and one resistance.
The suplly is made with SGS3525, and probably it doesn't start!
Much more clear photos.
https://picasaweb.google.com/115991106712336811055/January24201202#5701214458207098658
https://picasaweb.google.com/115991106712336811055/January24201202#5701214352685190850
https://picasaweb.google.com/115991106712336811055/January24201202#5701214462128042482
https://picasaweb.google.com/115991106712336811055/January24201202#5701214393917093202
I hope that this photos will better explain what i want to say!
The suplly is made with SGS3525, and probably it doesn't start!
Much more clear photos.
https://picasaweb.google.com/115991106712336811055/January24201202#5701214458207098658
https://picasaweb.google.com/115991106712336811055/January24201202#5701214352685190850
https://picasaweb.google.com/115991106712336811055/January24201202#5701214462128042482
https://picasaweb.google.com/115991106712336811055/January24201202#5701214393917093202
I hope that this photos will better explain what i want to say!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
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