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Russ White  
#61 Posted : Tuesday, June 21, 2011 7:42:58 AM(UTC)
Russ White

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Best I can see from your measurements now QP1 is likely dead. It appears there is a short at the base to the collector.

Please measure pins 2,3,4,6, and 7 of the opamp as well please.
Russ White  
#62 Posted : Tuesday, June 21, 2011 7:57:41 AM(UTC)
Russ White

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Btw, your prior measurements indicated a good QP1, so it could be something that occurred after the PS hookup issue.
tjencks  
#63 Posted : Tuesday, June 21, 2011 9:52:23 AM(UTC)
tjencks

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Thanks Russ,

I can replace it.
tjencks  
#64 Posted : Wednesday, June 22, 2011 3:55:30 PM(UTC)
tjencks

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Well Russ,

I replaced QP1...washed the board with a bit of alcohol and a brush...hooked it up. LED1 still was out.

I though I noticed some small spot of alcohol that had not evaporated ... I blew on it...all of a sudden here comes LED1 bright and beautiful. I check to see if I got lucky and sure enough 1.2V at the output...holy crap I thought I fixed it. I start checking the voltages on some of the opamp pins...the next moment LED1 blanks out again.

CRAP!

So I thought perhaps while checking the opamp I caused it to fail...I went to replace it again and in my haste pulled a pad off the board...yes dead Trident ;-( so sad. So now I must wait for you guys to produce the next batch which I hope will be soon.

In the mean time can you give me the part number for the beads that I removed at the bottom of the board. I will just replace that for now and go on minus the Trident at the 1.2V position.

A very sad day indeed...
Russ White  
#65 Posted : Wednesday, June 22, 2011 5:24:10 PM(UTC)
Russ White

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short term just use a bit of wire snipped lead from a through hole part.
suffolk tony  
#66 Posted : Thursday, June 23, 2011 1:33:41 AM(UTC)
suffolk tony

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Sorry to hijack this thread but a quick, related question; if I want to run the Buffalo without the Tridents can I bypass them by reinstating the links under the board, or do I have to unsolder them? (apart from the one which unplugs of course). I ask this because I have all the components to go dual-mono but only have one set of Tridents & I'd like to get everything up and running before the Tridents become available again.

Thanks for your help in anticipation!

Tony.
Russ White  
#67 Posted : Thursday, June 23, 2011 4:45:35 AM(UTC)
Russ White

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Yes you must remove them.
suffolk tony  
#68 Posted : Thursday, June 23, 2011 6:12:59 AM(UTC)
suffolk tony

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OK, noted. Thanks Russ.
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