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picovolt  
#1 Posted : Sunday, November 3, 2013 11:24:28 PM(UTC)
picovolt

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Built HD and HD PBP at the same time; just tested them. BP is working just as expected, but the HD is not working correctly. All LEDs lit, checked all 550 and 560 transistors (for orientation and solder joints), resistors, solder joints on everything. Twice.

These are most basic measurements, and I can provide photos and more measurements as required.

V in 10.85V AC
DC in 13.45V (TP GND1 & TP VIN)
V out is about 4.05 cold, then lowers to 3.9ish; turning VR2 has no effect at all on V out.
TP V REF is 3.87V which is correct I think.
CSS measures 0.00

Any suggestions where to look?
avr300  
#2 Posted : Monday, November 4, 2013 6:24:50 PM(UTC)
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Check orientation of D1.

Upload a snapshot.
picovolt  
#3 Posted : Monday, November 4, 2013 7:09:38 PM(UTC)
picovolt

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I'll send photos this evening (8 hours or so). D1 is correctly oriented (from memory, I spent a lot of time looking at this yesterday...) Are there specific photos, or just a lot of close ups of top and bottom of board? And—thanks for your help!!
picovolt  
#4 Posted : Tuesday, November 5, 2013 6:59:41 AM(UTC)
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Here's some close ups. I went through all transistors again this evening to make sure that none of the n & p were switched. The solder all looks good to me, but if any seem suspect, please let me know. I'm pretty cautious with using heat sinks on all semiconductors, but still might have burned out something. Is there a schematic that has voltage points noted around various components that could help me try and isolate where I've screwed up?
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mksung  
#5 Posted : Wednesday, November 6, 2013 6:38:13 AM(UTC)
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What mv is the value between tp-vin ~ tp-ccs? You can try to tune VR1 about 100mv and adjust the VR2 for the the 5V. If the output is over 5V and can't adjust down, can try to replace the R7 for 4K.
picovolt  
#6 Posted : Thursday, November 7, 2013 3:36:32 AM(UTC)
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I get 0.00 mv between CSS and Vin. Changing the VR1 doesn't make any difference. My output also can't be adjusted, and is near 4V.
mksung  
#7 Posted : Thursday, November 7, 2013 4:55:53 AM(UTC)
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It could take long time for troubleshooting, in my not professional opinion, I would recommend to replace all 550 and 560.
avr300  
#8 Posted : Thursday, November 7, 2013 5:50:08 PM(UTC)
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Some of your soldering looks dry to me. Are you sure they a good contact ?

Try re flow the whole board.
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thanks 1 user thanked avr300 for this useful post.
picovolt on 11/7/2013(UTC)
picovolt  
#9 Posted : Thursday, November 7, 2013 10:09:53 PM(UTC)
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Thanks avr—I'll get to this is either tonight or Friday night. Will let you know if that does it. If not, I think I'll pull the transistors one by one and replace them.
picovolt  
#10 Posted : Sunday, November 10, 2013 7:50:02 PM(UTC)
picovolt

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AVR—you were been right about the cold joints. I re flowed the board and kept testing it to see where the problem joint was. It was at R9, which had wicked through a fair amount of solder, but was still dry. In any case, it adjusted fine, and I've got my BIIIse and Legato up and running for the first time! Now to order the WaveIO and move up from toslink. (Have been waiting for TP board, but my sense is it could still be awhile longer.)
Thanks again!
avr300  
#11 Posted : Monday, November 11, 2013 7:22:54 PM(UTC)
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You're welcome. Glad I could help. ;-)
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