First time builder - failed voltage check [resolved]

[shroomalistic]

got the new parts in,  things are still off

T01: 84
T02: 215
T03: 0
T04: 213
T05: 196
T06: 0
T07: 122
T08: 0
T09: 195
T10: 0

i replaces all the caps at the power supply side and both wirewound resistors

LED's are not lighting also

[Paul Birkeland]

You kind of have to have one LED lit to have 84V at terminal 1.

The 196V at terminal 5 means that either the solder joint at A4/A5 isn't well soldered (which will cause one side of the 12AU7 not to glow) or the LED is open (this can happen from too much heat during soldering/resoldering).  Posting your DC voltages at A3 and A8 can help clarify which problem you have. 

The voltage issue at terminal 9 is an odd one and has me wondering if the octal socket is oriented properly (looks good in your photo) or possibly if the plastic keyway is snapped off of the 6080 tube.  If they keyway isn't broken, it could still be shoved in really hard and be off two pins which would short pins 5 and 6 together on the octal socket and provide the voltage issue you're experiencing.

[shroomalistic]

i got 0v at A3 and A8

check the socket and tube,  both are in right.  Tried one of my old 6080's also and still same voltage.

[Paul Birkeland]

Pull the 6080 and recheck the voltage at terminal 9 to let us know if it changes with no 6080.

You can't have 0V at A3 and A8 and 84V at terminal 1.  If your meter isn't auto ranging and it only has a higher voltage DC ranges, then it may not be able to resolve the ~1.5V or so that should appear at both A3 and A8.

Still, the 0V would tend to indicate a soldering issue at A4/A5.

[shroomalistic]

With 6080 out,  i get 0v at terminal 9

I can try to reflow a4 and a5, but when i test them I get the same 3.2v at each

let me know if you need pictures of anything to help.

[shroomalistic]

redid a4 and a5 still same results.

my meter is a sperry dsa-500.  its about 25 years old,  used it in my old heating and ac days

[shroomalistic]

my brother dropped off his multimeter,

T01: 190
T02: 207
T03: 0
T04: 208
T05: 191
T06: 0
T07: 192
T08: 0
T09: 191
T10: 0

a3: 0
a4: 3.1v
a5: 3.1v
a8: 18v

[shroomalistic]

i double check the new wire resistors and they were grounded.  UPS says the package was damaged in transit. 

I had a couple more that ordered off ebay and they are working

T01: 144
T02: 160
T03: 0
T04: 160
T05: 145
T06: 0
T07: 144
T08: 0
T09: 145
T10: 0

a3: climbs slowly till it hits 200 then starts over
a4: 3.1v
a5: 3.1v
a8: 14.4

[shroomalistic]

i checked the 12au7 for resistance
saw in another post to check a9 to a4 and a9 to a5
a4 is 0
a5 is 7

[Paul Birkeland]

Your voltages have now gotten worse and neither side of the 12AU7 is conducting.  Can you verify that the 12AU7 tube itself is glowing?  You could also have loose wiring at B7/B8 or where the green wires land on the power transformer. 

The 14.4V at A8 suggest that the LED there is damaged, and this happens from excessive heat being applied to the LED during soldering.

A3 can't climb to 200V, as there isn't a source in the amp for 200V DC. 

Looking at your build photos again, A9 does not look particularly well soldered.

[shroomalistic]

looks like only one side of the 12au7 is glowing but im not sure what it would look like with both sides?

I bought a magnifying/light arm to help me threw the rest of this,  should have did that first.  I can actually see what im doing now.

I have another 12au7 on the way and ordered new leds from you guys.

i had to put everything up for now and only have a few hours window a day.  Cant have it laying out with 4 kids running around.

Ill resolder a9 first thing tomorrow.  Plus ill have a new multi meter here tomorrow also.

[shroomalistic]

Forgot to tell you guys, THANK YOU SO MUCH FOR HELP!

I really appreciate the time you are taking here.

[Paul Birkeland]

If one half of the 12AU7 is glowing, definitely recheck the joint at A4/A5.  If it's loose at one of those connections, that will cause half of the tube to not light up.

-PB

[shroomalistic]

i have checked that multiple time and reflowed it.

[Paul Birkeland]

You can pull the 12AU7 out and check the DC resistance between pins 9 and 4 and pins 9 and 5.  It should be a very low value.