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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.
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Rank: Administration
Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN
Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
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Btw, your prior measurements indicated a good QP1, so it could be something that occurred after the PS hookup issue.
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Rank: Member
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Joined: 11/10/2010(UTC)
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Location: Campbell, CA
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Thanks Russ,
I can replace it.
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Rank: Member
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Joined: 11/10/2010(UTC)
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Location: Campbell, CA
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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...
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Rank: Administration
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Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN
Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
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short term just use a bit of wire snipped lead from a through hole part.
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Rank: Member
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Joined: 9/14/2010(UTC)
Posts: 84
Location: uk
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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.
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Rank: Administration
Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN
Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
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Yes you must remove them.
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Rank: Member
Groups: Member
Joined: 9/14/2010(UTC)
Posts: 84
Location: uk
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