Driver testing failure

Jamus · 5799

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Offline Jamus

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Reply #30 on: June 28, 2016, 02:28:17 PM
Paul, no worries on the mixup I'm just grateful for the help!
Kreg A = 0
R3 = 250 and 5250 ohms
-reg = 8800 ohms and slowly rising
Ground and -reg are the same
I resoldered both ends of R3 multiple times, and get the same reading at -reg. Could then be an issue with the board/terminal preventing the connection? I must have touched up R3 a dozen times since it was first suggested as the likely source of the problem.
Thanks again for helping out.
Jamus

Rega Planar3/Elys2 - Eros - BeePre - Kaiju - Klipsch Forte I's
Marantz CD5005
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Online Paul Joppa

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Reply #31 on: June 28, 2016, 03:30:30 PM
Those look better - presumably the trimpot is set to250 ohms, very close to one end of its range. The only anomaly is that one end of R3 should be connected to -reg.

On the back side of the PC board you can see the trace that connects the end of R3 closest to the 431 chip to one terminal of the Cc capacitor and from there to -reg. From your measurements, it seems clear that something is wrong with that connection. The total length of that trace is barely 1/2 inch - I'd say we have narrowed it down pretty close ...  :^)

If you can't find it from that, can you post a photo of the back side of the board? Maybe getting more eyes on it will help.

Paul Joppa


Offline Jamus

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Reply #32 on: June 29, 2016, 11:20:32 AM
Okay, I think I see the problem. It really helped knowing where to look so thanks Paul for helping narrow it down within 1/2 inch!

It appears to me that the trace between R3 and Cc is not complete (bottom of the image). If you zoom in on this picture you can see a small notch in the trace. The metal around the Cc terminal is also incomplete.

Am I seeing that right?

Rega Planar3/Elys2 - Eros - BeePre - Kaiju - Klipsch Forte I's
Marantz CD5005
Crack w/Speedball - Senn HD650


Offline Doc B.

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Reply #33 on: June 29, 2016, 11:35:26 AM
Yup looks like it is open right there. Easiest solution is to make up a wire jumper that reconnects the disconnect.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Jamus

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Reply #34 on: June 29, 2016, 11:40:59 AM
Just so I'm clear, jumper from R3 to Cc?

Rega Planar3/Elys2 - Eros - BeePre - Kaiju - Klipsch Forte I's
Marantz CD5005
Crack w/Speedball - Senn HD650


Offline Jamus

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Reply #35 on: June 29, 2016, 11:48:55 AM
R3 hole is too small to fit a second wire through. Any other options?

Rega Planar3/Elys2 - Eros - BeePre - Kaiju - Klipsch Forte I's
Marantz CD5005
Crack w/Speedball - Senn HD650


Offline Doc B.

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Reply #36 on: June 29, 2016, 12:02:14 PM
You can carefully scrape the green solder mask from the trace and tack solder the end of the jumper to it. The soldering also needs to be done with some care so the trace doesn't lift off the board.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Jamus

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Reply #37 on: June 30, 2016, 01:57:10 PM
I installed the jumper tonight and sure enough that did the trick! Now getting the same resistance at R3 and -reg, powered up and voltages are in spec, trip pot is trimming, all is good in the world.

This was a long strange detour and I couldn't have navigated it without the help of PJ, Josh, PB, and Doc B. Many thanks for sticking this one out!

Best,
Jamus

Rega Planar3/Elys2 - Eros - BeePre - Kaiju - Klipsch Forte I's
Marantz CD5005
Crack w/Speedball - Senn HD650


Offline Doc B.

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Reply #38 on: June 30, 2016, 02:24:35 PM
Awesome! We will be sending out a replacement for the defective board tomorrow.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.