News: Not receiving your account activation email? Contact [email protected]
November 24, 2020, 02:45:45 PM

Author Topic: Help troubleshooting - Smashup - C side two leds do not light [resolved]  (Read 658 times)

0 Members and 1 Guest are viewing this topic.

Offline notphilip

  • Jr. Member
  • **
  • Posts: 10
I recently completed the smash and decided to do the smashup upgrade.

Upon completing it and powering it on, I found that both tubes light up but the two leds on the B side of the C-tube PCB do not light up.

The voltages on the A-tube are measuring perfectly, and all voltages on the B tube are correct except for B5-B6 (which are downstream from the C-tube PCB).
It appears that the C-tube PCB is taking 210V in, but then outputting 5V instead of 150V.

Any ideas?
At this point, I'm not sure what to do.

I've continuity tested all the wires to the PCB, removed the PCB to check/reflow solder on all the joints, and reinstalled all connections to the PCB.
I particularly ensured that the center leg of the transistors passes a continuity test with points that are downstream of the trace - and made sure that every point passed a pairwise continuity check with another point downstream of the trace.
I've also verified that the board layout is exactly the same as the A-tube and triple-checked/reinstalled all connections to the PCB board.

Pics can be found here: https://1drv.ms/f/s!AuxARZLrKSc6s80g55lE-_NMqWROnQ
Below are some measurements:
Terminal   Target   Trial 3
IA   180-220   207
OA   150+-1%   150
reg+ (a side)   2.5   2.51
IB   150+-1%   150
OB   45-75   61
KREG (B)   3 - 5   4.5
BREG (B)   150 +- 1%   150
Reg+ (b side)   150 +- 1%   150
      
IA   180-220   207
OA   150+-1%   5
reg+ (a side)   2.5   2.5
IB   150+-1%   5
OB   45-75   3.76
KREG (B)   3 :- 5    1.6
BREG (B)   150 +- 1%   5
Reg+ (b side)   150 +- 1%   5
      
B1   0   0
B2   150   150
B3   3 - 5   4.5
B4   0   0
B5   150   5
B6   3 - 5   1.7

« Last Edit: December 14, 2016, 07:45:31 AM by Caucasian Blackplate »

Offline notphilip

  • Jr. Member
  • **
  • Posts: 10
Re: Help troubleshooting - Smashup - C side two leds do not light
« Reply #1 on: December 14, 2016, 06:07:57 AM »
Got it fixed this morning. For posterity, this was due to the .1 uF capacitor having been grazed by the soldering iron. I replaced it with the capacitor removed from the stock kit and everything measured perfectly. It sounds great! Background hum is still a bit loud unfortunately but I think that's something I'll just need to fix with attenuators.