Need Help With Blown Power Amp
Tchesco
Posts: 2
Hi everyone,
I'm a newbie in this forum and a newbie in electronic... But I'm wondering if some one could help me ! I'm rebuilding a power amp whose output transistor blast..
I have exchanged the bad one and the power resistor to at their back.
Now i'm checking all the transistors and drivers, rectifiers etc... and I found a resistor who cause me trouble, I'm not able to really understand the color code !
Here is the resistor explanation : It is 1/4 watts type, is color brownish, (first I though it was red, but it's brownish..) my first color is (left to right) brown, black and gold, ok, up to here it is quite simple I guess, but there is another color and the extreme right witch is yellow, and that confuse me a lot.
Don't know if it is a military type resistor with a tolerance of 0.001%, or temp code ?
And, in the mean time I'm wondering the composition of this transistor. Carbon composed, obviously it's not a metal film resistor. Could it be flame proof type ?
Hope I'm gone find a answer Through a knoweldge person.
Tchesco- Montreal
Post Edited By Moderator (Chris Savage (Parallax)) : 8/21/2005 12:46:50 AM GMT
I'm a newbie in this forum and a newbie in electronic... But I'm wondering if some one could help me ! I'm rebuilding a power amp whose output transistor blast..
I have exchanged the bad one and the power resistor to at their back.
Now i'm checking all the transistors and drivers, rectifiers etc... and I found a resistor who cause me trouble, I'm not able to really understand the color code !
Here is the resistor explanation : It is 1/4 watts type, is color brownish, (first I though it was red, but it's brownish..) my first color is (left to right) brown, black and gold, ok, up to here it is quite simple I guess, but there is another color and the extreme right witch is yellow, and that confuse me a lot.
Don't know if it is a military type resistor with a tolerance of 0.001%, or temp code ?
And, in the mean time I'm wondering the composition of this transistor. Carbon composed, obviously it's not a metal film resistor. Could it be flame proof type ?
Hope I'm gone find a answer Through a knoweldge person.
Tchesco- Montreal
Post Edited By Moderator (Chris Savage (Parallax)) : 8/21/2005 12:46:50 AM GMT
Comments
-dave
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This is not a sig. This is a duck. Quack.
Just got back in town yesterday night, yes i will send you a picture.
Thanks again.
Fran
If you are doing this without the aid of any schematic, you are likely to mess up. At least try to reverse engineer a schematic to see the design concept. Then you may use SPICE to verify the design's stablity.
Also, many of the old transistor audio power amps had rotten designs with runaway heat problems, a lot of 60 cycle hum, or destructive feedback. You may want to check with audiophiles to see that your amp doesn't have such design flaws.
If it does, you will have to consider modification or merely restoring something that may be a piece of audio history, but never fully operational.
I bought a low of audio amps in flea markets and would repair them, but many times my audiophile friends would recognize the unit as being a 'lemon'. Most of the guys that make money stay away from these 'difficult units'.
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G. Herzog in Taiwan