Help with Seduction with C4S

[JKay]

Hi Guys,

It's been a long time since my last post and am looking for some help.  I just got a new Fluance table and had it running through the Seduction fine for a about an hour.  I came back the following day and no sound out of the Seduction.  I did all sorts of troubleshooting and even swapped it out for the Eros in my main system.  Still no sound.

I went though all the resistance checks and voltage checks.  The only ones that look wrong are A8, B8.  These are supposed to read 1 Meg ohm+.  My reading was OL.  I double checked this.  All the LEDs on the board and near the tube sockets are lit.

Any ideas on what this could be?  There's a chance that the input and/or output RCA's were unplugged by accident while the Seduction was on, but I really can't be sure. 

Thanks,

John

[Paul Birkeland]

Pin 8 on each tube socket is the cathode, which goes to ground through an LED and isn't going to show much as far as resistances go.  Pin 2 on each 9 pin socket would show a 1 meg resistance.

On the old Seduction C4S boards there are four wires that leave the board and go to the area around the 9 pin sockets. what DC voltages do you get at each of those pads? 

If you lost both channels, I would bet that your tubes aren't glowing, can you have a look to see if they are?  If they aren't, that's a pretty easy problem to debug on its own.

[JKay]

Thanks for the fast response!

Pin 8 on each socket is showing 0.L on my meter, which is infinite resistance, right?  Pin 2 on both sockets show 1 meg.

Here's my voltage readings:

From lower C4S board

A7/B7  0V, 0V
A8/B8  1.5V, 1.5V
A9/B9  0V, 0V

From upper board

27/37  70V, 66V
34  125V
42  61V
32  65V
42  61V
'
I rechecked my resistances and found a few changes.  A3/B3 read 0.L.  Pins 12, 15, and 25 all read 0.L (these are the positive terminals on the 3 large electrolytics).  I did drain these caps before taking any resistance measurements.

The tubes are lit.  These are new tubes that I put in after I started having issues.

[JKay]

Paul,

I decided to throw it back in my system to try and it's making music again.  Maybe I have a loose connection somewhere.  I'm open to suggestions as to any particular points where I need to reflow some solder.

Thanks for your help!

John

[Paul Birkeland]

These are the points where you want to measure DC voltage.

[JKay]

Measured:

42  Black  61V
37  Yellow  66V
32  Blue  65V
27  Red  70V

[Paul Birkeland]

Those are working voltages.  You likely do have a loose connection.

[JKay]

Thanks Paul; appreciate it buddy!

[kgh]

Any ideas on what this could be?  There's a chance that the input and/or output RCA's were unplugged by accident while the Seduction was on, but I really can't be sure. 

Is this bad if you unplug the inputs and outputs while it is on?  What will happen?

[Doc B.]

It will stop playing music until you plug the cables back in.

[kgh]

Hahaha, and here I thought it would produce catastrophic damage from the way I read it! Guilty as charged for unplugging RCA jacks while it's running. Now I can rest easy.