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Old 3rd June 2010, 08:10 PM   #31
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Location: Cambridge, England.
Originally Posted by svokke View Post
Today I took one of the transistors apart. I think this looks like a bipolar. So it really could be the 2SA940 or KSA940, both PNP devices. Is this die about the correct shape and size for those transistors?
Can you measure the junctions still? It looks like just the bond wires have been blown away..
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Old 3rd June 2010, 08:48 PM   #32
svokke is offline svokke  Belgium
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The transistors measure completely open or short circuit between the pins. Not a single transistor measures like a PN-junction.
Edit:Maybe I interpreted your post wrong. Tomorrow I will try to measure directly on the junctions.
In illusion comfort lies

Last edited by svokke; 3rd June 2010 at 08:52 PM.
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Old 3rd June 2010, 10:47 PM   #33
Nrik is offline Nrik  Denmark
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Originally Posted by svokke View Post
The most left pin of Q6 goes to the middle pin of Q1(=collector) in your picture. I have re-drawn the schematic.
In that case it is safe to say that all four transistors must be PNP.
Replace with four new ones and your amp should be as good ( ..or as bad ) as before.
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