nashou
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Post by nashou on Mar 3, 2014 19:59:59 GMT -5
Ok I measured at R 493 for the -54 the top leg of Q417 was -51 and J536 was -51 as well.
I think those are good points
Nashou
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Post by mastertech on Mar 3, 2014 20:16:21 GMT -5
Where is J536?
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nashou
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Post by nashou on Mar 3, 2014 20:22:42 GMT -5
Attachments:
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nashou
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Post by nashou on Mar 3, 2014 20:27:32 GMT -5
The leg that goes to R551 is 50.3 J536 is 51.3 and R493 is 53.5, All NEG.
Nashou
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nashou
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Post by nashou on Mar 3, 2014 20:34:16 GMT -5
What should be seen at those points? Or at each TP 402 etc?
Nashou
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Post by mastertech on Mar 3, 2014 20:34:35 GMT -5
Do a diode test of Q417. Make sure it is unplugged.
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nashou
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Post by nashou on Mar 3, 2014 20:51:56 GMT -5
What should be seen at those points? Or at each TP 402 etc?
Nashou
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nashou
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Post by nashou on Mar 3, 2014 20:58:51 GMT -5
Do a diode test of Q417. Make sure it is unplugged. Neg probe from R493 to the outer leg pos probe shows .182 flipping the leads shows a short . Also a short from R493 to J536 Nashou |
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Post by mastertech on Mar 3, 2014 21:03:49 GMT -5
The TP's are for setting the idle current.
On Q417, when base is high it should be turned off. So there should be zero output (emitter). You have voltage so either there is some feed back or it is shorted. just need to verify if shorted again or not. This was replaced, correct?
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Post by mastertech on Mar 3, 2014 21:04:56 GMT -5
Do a diode test of Q417. Make sure it is unplugged. Neg probe from R493 to the outer leg pos probe shows .182 flipping the leads shows a short . Also a short from R493 to J536 Nashou Remove Q417 and retest. |
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nashou
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Post by nashou on Mar 3, 2014 21:17:53 GMT -5
Neg probe from R493 to the outer leg pos probe shows .182 flipping the leads shows a short . Also a short from R493 to J536 Nashou Remove Q417 and retest. Apart now going to remove it. |
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nashou
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Post by nashou on Mar 3, 2014 21:42:16 GMT -5
Yep it is bad...... but now the circle pad around the holes fell out. I'll have to solder the leads to the traces or to the closest part.
Should I replace it or test other parts near by?
EDIT: the 100 Ohm resistor was one of the 1/4 watts and not the 1 watt like it should be but it reads fine and the leads seem as thick or thicker than original
part.
Nashou
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Post by mastertech on Mar 3, 2014 21:53:00 GMT -5
were the other 100 watters R439 and R415 that you used 1/4w instead of 1w?
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nashou
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Post by nashou on Mar 3, 2014 21:53:17 GMT -5
WAIT!!!! I just realized I may have changed the wrong resistor !!! R493 is not 100 Ohm its 4.7 Ohm!!!!
I bet that made the Transistor fry.
Not sure if I have a 4.7 ohm resistor.
And yes those others are 100 ohms as well , they are a very high quality type tho Vishay CMF55100R00FHEK
Nashou
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Post by mastertech on Mar 3, 2014 21:55:05 GMT -5
I'm showing R493 is 33ohm.
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