Crack help

[patm]

Crack build not going so well. For info, I amusing a locking jack and a Goldpoint Attentuator. The resistance checks all look good except for 13. Instead of climbing to 270k, it's falling from 6m. The voltage checks are as follows (I have checked the orientation of the caps and diodes at least 10 times and all is as it should be and I also have gone through the instructions and determined that everything is wired correctly)

1    BH.                ME
2      90.                  -1.2
3      170.                -1.2
4        0.                    0
5      170.                -1.2
6.      0.                      0
7.    100.                  0
8.      0.                      0
9.    100.                  0
10.    0.                    0
11.    0.                    0
12.    0.                    0
13.    170.                -1.2
14.    0.                    0
15.    185.                240
20.    0.                    0
21.    206.                240
A1.    90.                -1.2
A2.    0.                    0
A3.    1.5.                  .2
A4.      0.                  0
A5.      0.                  0
A6.      90.                -1.2
A7.      0.                  0
A8.    1.5.                .3
A9.      0.                  0
B1.      90.              -1.2
B2.    170.              -1.2
B3.    100.                0
B4.      90.              -1.2
B5.      170.            -1.2
B6.      100.              0
B7.        0.                0
B8.        0.                0

 

[jrebman]

Pat,

These readings, on the surface, look pretty similar to the other guy who just had problems -- is your fuse ok?

-- Jim

 

[Doc B]

Power supply is working at 240V. It's not being pulled down because the tubes are not drawing current. Ergo, your heaters may not be hot...check the  heater voltage at the tube sockets

 

[patm]

Jim, I re-read the post and the numbers do look the same but my fuse shows .2 to .5 so it seems fine. I forgot to mention that I found two un- soldered wires and fixed them as I was going back through the manual. I also discovered this morning that I wired the Goldpoint backwards. The RCA's are wired to IN and the circuit is wired to out, I'm embarrassed.

Doc after I fix my Goldpoint mistake I will recheck voltages and note the heater readings. Thanks for the help. I have built three BH Kits and I guess I got over confident, I built this kit in 6 hours, I have always done better work when I go slower.

Pat

 

[patm]

Ok I'm through rewiring the Goldpoint, in to in and out to out. I just rechecked the voltage readings and nothing has changed from my original post.

Doc I get 0 vdc at pins 4&5 to pin 9 on the 9 pin and 0 vdc between 7 & 8 on the 8 pin and of course the LED's are not lit you were correct no power to the heaters.

 

[Doc B]

The heaters run on AC in the Crack. Set your meter to AC and measure the heater voltage at those same places again.

 

[patm]

I get 5.9 vac in both places.

 

[Doc B]

OK, the tubes may be heating up but you just can't see the filament glow. I don't have the terminals down like PB or Shawn does to be able to tell you which terminals to check, but it sounds like you need to trace the connections from the power supply filter on the strips around the power transformer over to the 6080 socket. It seems like the high voltage is not making it from power supply to tube

 

[Paul Birkeland]

Can you post a pic of the bottom side of your Crack?

Can you confirm that the 270k resistor is soldered across the last power supply cap? (that is laying down)

Also, check the red wire that leaves that last power supply cap and travels to the octal socket.  It looks like you are making your positive high voltage, which is good, but it's not leaving the area back by the power transformer and reaching any of the tubes. 

Do not worry about the heater voltages, you will get higher than normal voltages in more places if the tubes aren't heating up.

-PB

 

[patm]

First I think I need to say that the tubes glow, I forgot to mention that before and I think There may have been some confusion about that. PB, there are pictures of the areas you mentioned here http://photobucket.com/albums/q517/Patmcsween/Bottlehead Crack  I get continuity on that red wire from 13u to B5 to B2 to 2L

Pat

 

[patm]

Seems that the previous URL is bad, let's try this one http://s1161.photobucket.com/albums/q517/Patmcsween/Bottlehead%20Crack/

 

[Paul Birkeland]

Verify the connection of the 270 ohm resistor that feeds 13U.  I see you have voltage just before 13, but not at 13.  This resistor will connect between the two unstriped sides of the two black capacitors on that side of the chassis. 

-PB

 

[patm]

OK thanks so much Paul and Doc. It was the resistor. I missed the end at 13L probably the hardest place to get to on the entire build. That being said, THIS THING SOUNDS GOOD, dead quite. Using my brothers HD 650's. Now I have to decide which phones to get. Lovely Delma.

 

[Grainger49]

Pat,

Glad you found the problem.  This little amp is pretty simple so the jump from 240V to zero is a pretty good indicator of an open circuit. 

I'm amazed at guys who sweat over a checkout and come back with almost the identical statement, "This thing is... dead quiet."  This should give hope to those searching out an elusive noise problem.  There are so many Cracks out there that are Dead Quiet!

 

[patm]

Yes Granger, the only bad mistake is one you don't learn from. I learned to not push so hard and a tiny bit more about the circuit and trouble shooting. I have read posts where you offer advice on posting pictures directly to the Forem. Any chance you have that procedure in digital form that you could pm me?

 

[Grainger49]

Pat,

I will send you a PM.