Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: rsmiii on April 10, 2021, 11:19:21 AM

Title: Voltage Check Fail; Help Diagnose?
Post by: rsmiii on April 10, 2021, 11:19:21 AM

Eros 2.0 Manual (2018), page 55:
I did not quite pass the Voltage Checks on the tabs of each MJE5731A.
One was about 199VDC, the other about 196VDC.
A "pass" should be between 210–230 volts.

I checked the red and white wires connecting the board to the circuit; seems fine – on cursory but not thorough check.

I disclose, with embarrassment: I did connect power *before* I had installed the 12AU7 tube.
I caught my mistake within about 30 seconds and unplugged.
Did I fry one of the sensitive components? Must I start over from page 45 with new components?

Advice appreciated.

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: Paul Birkeland on April 10, 2021, 12:53:35 PM

No, it's unlikely that you fried anything.  What are your Kreg voltages?

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: rsmiii on April 11, 2021, 06:45:41 AM

Paul, thank you for your reply.
If by "Kreg voltages" you mean the DC volt measurements at each of the A&B "Kreg" points on the printed circuit board, with the negative (black) lead on the ground, then I measured 1.9VDC on each of the A & B Kreg points.

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: Paul Birkeland on April 11, 2021, 07:02:39 AM

How about the voltages at IA and IB?

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: rsmiii on April 11, 2021, 07:13:31 AM

Paul: about 291DCV on each of 1A and 1B.

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: Paul Birkeland on April 11, 2021, 07:36:24 AM

Can you post some photos of the build so far?  Also if possible the bottom of the C4S board?

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: rsmiii on April 11, 2021, 08:04:15 AM

Paul: detail pictures of my Eros 2.0 build as of 4/11/2021, through page 55 of the manual (2018).

Title: Re: Voltage Check Fail; Help Diagnose?
Post by: Paul Birkeland on April 11, 2021, 05:26:22 PM

You may benefit from more solder on the PC board joints.  Also on the 9 pin sockets, you want to wrap the leads of the wires/resistors up and over the top of the socket pins, not around the sides.  There just isn't enough clearance to reliably have them wrapping around the sides.