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Old 2nd March 2014, 11:02 PM   #1
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Smile Problem with Pearl 2

Finished assembling my Pearl 2 yesterday. I started it up with a variac and when I got to about 50% it blew the fuse. Replaced fuse and put a multi-meter on the output and got lots of voltage on the output (2 volts before shutting it down).

I'm using an XLR connector for voltage between two chassis and didn't understand that the shield connected a pin and the sockets. I clipped the wire going to the sockets thinking I had solved my problem.

Started testing again today and am still getting negative voltage on the output (both boards behave the same). Almost as much voltage as is going into the board itself. I have done a lot of testing to make sure I don't have any shorts in the wiring.

I pulled one one board and can't find anything out of place. I'm stumped at this point.
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Last edited by KevinHeem; 10th March 2014 at 01:05 AM.
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Old 3rd March 2014, 01:44 PM   #2
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Looks like same setup I have on my pearl. Sent you an IM. I can send you some pics of my setup so you can compare
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Old 3rd March 2014, 04:30 PM   #3
omishra is offline omishra  India
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Check orientation/polarity of red LED. I can see clearly in pic.
Also check polarity of power supply getting into phono box.
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Old 4th March 2014, 04:03 AM   #4
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I'm pretty sure the LED is orientated correctly...but I pulled it anyway and put one in the opposite direction. I get the same results. (- dc voltage on the outputs).

I know the polarity of the power supply going to the phono box is correct because I've check it numerous times.
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Old 4th March 2014, 03:38 PM   #5
6L6 is offline 6L6  United States
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Quote:
Originally Posted by KevinHeem View Post
I get the same results. (- dc voltage on the outputs).
Is it still blowing fuses? Or has that problem been fixed?
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Old 4th March 2014, 11:22 PM   #6
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I haven't pushed it past 50% on the variac because I see all that voltage on the output and test pad. I'm sure it would blow the fuse, so no it hasn't been fixed yet. I need to go get an LED and more fuses before testing more.
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Old 7th March 2014, 04:03 AM   #7
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Well...I have one channel working!

The other channel is the one I switched the polarity of the LED which made R29 smoke. I have the LED back in correctly and replaced three other parts, R29, Q2, and Q11. Now Q11 gets very hot. I had it hooked up and it has very little gain.
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Old 7th March 2014, 08:14 AM   #8
Itsmee is offline Itsmee  England
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Quote:
Originally Posted by KevinHeem View Post
I see all that voltage on the output and test pad.
Quote:
Originally Posted by KevinHeem View Post
Now Q11 gets very hot.
Looks like Q2 is fully turned on or oscillating, remove C7 if fitted, if that doesn't fix the problem, replace the ZVP3310 - is very sensitive to static.
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Old 7th March 2014, 11:53 PM   #9
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I replaced Q2 twice now. Q11 still gets really hot. I have nothing in C7.
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Old 8th March 2014, 01:58 AM   #10
6L6 is offline 6L6  United States
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Something is shorted...
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