Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: adeep42 on June 28, 2019, 07:02:22 AM

Title: Eros 2 Help 2
Post by: adeep42 on June 28, 2019, 07:02:22 AM

Been moving along slowly and carefully since previous issue. Just completed build, Resistance checks are perfect. Some of the voltage checks seem to be out of the 10% +/- range, Particularly 1A and 1B.

1A   140
1B   272
OA   138
OB   132
OC   93
OD   97
OkA  95
OkB  98
OkC  1.39
OkD   .867

Your thoughts.

Thanks and best,

Alan

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on June 28, 2019, 07:31:10 AM

IA and IB come from the regulator that's built on/above the D socket.  If you remove those blue wires from IA/IB on that main C4S board, what do you now see at +reg on the C4S board above the D socket?

It is possible that there's still an issue at the D socket that needs to be resolved.

-PB

Title: Re: Eros 2 Help 2
Post by: adeep42 on June 29, 2019, 04:51:59 AM

Good Morning Paul,

It's 7:45AM your time. It's okay with me if you don't get to this til Monday.

  A side +reg  196.5 VDC
  B side +reg  291.00 VDC 

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on June 29, 2019, 06:09:02 AM

Yeah, at least one side of your regulator board isn't working again.  I would recheck your Kreg voltages and double check those D socket connections again.

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 01, 2019, 07:59:32 AM

Just finished total check of D socket and Shunt Regulator Board. Now voltage at the MJE5731As is A @ 295, B @ 294.

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 01, 2019, 09:54:14 AM

So now neither regulator is working properly.  Are all the tubes still glowing?  What voltage do you get across the 6.3V terminals on the power supply board?

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 01, 2019, 05:19:55 PM

Tubes all glow.

Voltage is 6.3vDC.

LEDs on A side of shunt regulator light up and are steady. LEDs on B side flash several time and then go out.

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 02, 2019, 05:44:53 AM

This is with the wires going to IA and IB on the front board disconnected right?

What are the Kreg voltages on the board above the D socket?

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 02, 2019, 10:19:10 AM

NEW BALLGAME!

My mind is spinning. Keep going over everything touching up solders, etc.  Found a mistake. White wires from D socket went to the wrong kregs. Switched them. Reattached wires to IA and IB. Only 2 voltages now outside the range.

IA   110.4  ?
IB   218
OA  108.3   ?
OB  154
OC  94.9
OD  96.6
OkA 95
OkB 98
OkC 1.5
OkD .866

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 02, 2019, 12:33:52 PM

With the Kreg wires properly installed, how did the regulator board check out before you hooked it back up to the front C4S board?

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 03, 2019, 06:01:20 AM

A Side MJE5731A   220VDC
B Side                   177VDC-off by 15%

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 03, 2019, 06:08:59 AM

OK, I would leave the IA/IB wires off the smaller C4S board and debug the shunt regulator.  What are its Kreg voltages?

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 03, 2019, 06:29:59 AM

kreg A   3.21

kreg B    .625

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 03, 2019, 06:40:55 AM

What's the voltage at the X terminal on the B side?

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 03, 2019, 06:48:27 AM

175 vDC

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 03, 2019, 07:04:14 AM

The one that's closer to the center of the long edge on the board, not the one by +reg.

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 03, 2019, 07:11:53 AM

I don't see an X on that part of the board
.

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 03, 2019, 07:12:52 AM

This?

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 03, 2019, 07:23:10 AM

Sorry, it was obscured by the cap.

2.48 vDC

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 03, 2019, 07:26:40 AM

If you have 2.5V (2.48 is close enough) on that X terminal on the B side but Kreg is 0.6V on the same half of the board, you most likely have a miswire from the Kreg terminal to the D socket, or an ungrounded grid (D2 and D7 are the grids).

When you said before that you got "good readings" in your shunt regulator test, what were those readings exactly? 

You seem to have about the same problem you had previously.  It might be a good idea to go over the solder joints on the board above the D socket again.

Title: Re: Eros 2 Help 2
Post by: adeep42 on July 03, 2019, 08:15:15 AM

Hi Paul,

Think it's time to send this puppy to you.

Please advise.

Alan

Title: Re: Eros 2 Help 2
Post by: Paul Birkeland on July 03, 2019, 09:42:26 AM

https://bottlehead.com/product/repair-service/ (https://bottlehead.com/product/repair-service/)