Did I blow it? [solved]

[danox574]

I am assembling the BeePre and the BeeQuiet simultaneously.  I have completed the BeePre and the only thing left to do is install the BeeQuiet resistors on the switches, everything is up to the BeeQuiet terminals.  A quick glance at the circuit indicated to me that shouldn't matter, I decided to do my resistance and voltage checks now.

Resistance was good on 1-10 except 10 - which should be 20K+ but was 1.8M (so maybe that's right).

B side C4S LEDs are NOT lit up.  IB is 190V.  300B Tubes are not lighting up.

Voltages on 1-10 (3, 5, 7, 8, and 9 should be 0V and are).
1. Should be 5v - .77V
2. Should be 90-110V - 189V
4. Should be 9.85V - 1V
6. Should be 146V - 190V
10. Should be 186V - 192V
A2. Should be 0V - 190V
A3. Should be 90-110V - 0V

This is duplicated with a few volt variation on the terminal 11-20 side.

Is there a load in the volume controls that has to be there for this to work?  If that's the case, would I have damaged anything during this?  I didn't see how it would matter, but the fact that I have the exact behavior on both sides makes me wonder if I missed something.

I will wire in the volume resistors as soon as I get your feedback.

Thanks,
-Dan

[Paul Birkeland]

I am assembling the BeePre and the BeeQuiet simultaneously.

We specifically recommend against doing this whenever anybody asks.  Trying to do both at once leaves a lot of opportunity to make mistakes, as you have to skip some steps in one manual and substitute them with directions from another manual.  When it comes time to troubleshoot, you really have to remove the upgrades and go back to the stock kit to be able to debug the build.

Is there a load in the volume controls that has to be there for this to work?

Yes, this is one of the reasons why the kit should be built stock first.

  If that's the case, would I have damaged anything during this?

We won't know, it seems equally likely either way. 

Please complete the stock build without the BeeQuiet, then we will be better able to assist you with any issues that may have arisen during the build.

-PB

[danox574]

We specifically recommend against doing this.Yes, this is one of the reasons why the kit should be built stock first.We won't know, it seems equally likely either way. 

Please complete the stock build without the BeeQuiet, then we will be better able to assist you with any issues that may have arisen during the build.

-PB

Afraid I've been over the manuals a few times and don't see the recommendation, although it could qualify for common sense, I wanted to go straight to my final configuration rather than rework.  Wasn't in the box with the free BeeQuiet I got with the BeePre.  I guess for proof of concept we could just have put the volume pot in alone to determine what was going on, but hey, I need help and so I did exactly what you asked.  Rework is tough on some of these parts, so it was slow going, but it's done for you.

The PT-7 A side is glowing the 300B tube without a problem now, and all 4 lights on the C4S board come on.  The PT-7 B side, however, is still two lights only, no heater on the 300B on that side - it's behaving exactly like it did without the volume pot.  I've double checked my wiring on the pots and I think I have it right.  What would you suggest?  I could switch the C4S boards to see if the problem moves with it, indicating I've damaged something on the board, or the problem is elsewhere.  But maybe you have a more targeted idea?

(Doesn't the manual have the A2/A3 and B2/B3 suggested voltages reversed?)

[Paul Birkeland]

Can you post the voltages that you have that are out of the recommended range in the manual?

Thank you for putting the stock parts back in.  It makes a huge difference to know that a 300B grid isn't floating. 

I let the manual writer know about the pin2/3 voltages, pin 3 should be 0V and pin 2 will have something around 100V. 

-PB

[danox574]

Like I said, it's identical to the report in the first post, but here it is translated over to the B side on a fresh retest.  No LEDs on the B side of the C4S board, A side is dimmer and takes longer to come up than the working side.

It's behaving identically to when the volume pot was missing from the circuit.

11 - should be 146v - 194v
16 - should be 5v - .15v
17 - should be 90-110v - 194v
19 - should be 9.85v - .15v

The other 6 pins are in spec.

B2 - should be 90-110v - 190v
IB on the C4S board is 191v

Frustrating, because I figured when I wired the pots in, it would either WORK or NOT, but I ended up with one of each :/

[Paul Birkeland]

What do you see for a DC voltage between "neg out" and "pos out" on the filament regulator board on the offending channel?

[danox574]

.088V.  It's 9.85V on the good side.

[Paul Birkeland]

How about between neg in and pos in?

[danox574]

How about between neg in and pos in?

1.043V.  It's slightly over 10 on the good side.

[Paul Birkeland]

Try removing the POS in wire, then measure the voltage from neg in to the loose wire.

[danox574]

Try removing the POS in wire, then measure the voltage from neg in to the loose wire.

6.77V.  Started at 6.9V and settled to that.  It was as well before connected during the tests starting on page 33.

It bothers me so much that I wired in the controls and one side behaved normally and the other side didn't.  I keep checking my wiring on the pots over and over again thinking I haven't done something right, but I don't see anything.

[Paul Birkeland]

You have a wiring issue under the PC board, with the two shottky diodes and the two 10,000uF caps.

You can pull both boards, then check from side-to-side.  It may be that you don't have the jumper in place between the two 10,000uF caps.

-PB

[danox574]

Not exactly sure what to check besides what I'm showing you here.  Cap orientations are correct, I have a short from 29 to 30, cap measurement on 31 to 28 shows 4,000uF at the terminals and at the board Neg/Pos In.  Diode bridge is correct and shows no shorts.  I know this top view you can't tell if I have a short in crossing wires, but I can tell you for sure I do not.

(https://farm4.staticflickr.com/3926/15384793381_a336c4d985_c.jpg)Untitled by danox574, on Flickr

(https://farm4.staticflickr.com/3864/15201470027_c20ae280cf_c.jpg)Untitled by danox574, on Flickr

Do you see anything?

[Paul Birkeland]

Lift those 10,000uF 10V caps up and have a look underneath.  It's possible that one diode is backwards.

[danox574]

Actually, after I posted these photos I went back and reflowed the solder points on all four UF4007 rectifiers and BINGO, up and running.  Everything works, nothing appears to be damaged.  That was Terminal 6 and 7 on the PT-7 and terminal 39 and 40.  Don't have power amps yet so just ran the outputs through a Stereomour input and all was well.

I came back to post but I was shown as banned from the forum (probably admin stuff going on) and now just checked again, so I wanted to update the thread right away.

Thanks so much Paul, I really appreciate the time and assistance.

-Dan