News: Not receiving your account activation email? Contact [email protected]
November 30, 2020, 11:52:14 AM

Author Topic: Voltages are off after smashup upgrade [solved]  (Read 1322 times)

0 Members and 1 Guest are viewing this topic.

Offline RW

  • Full Member
  • ***
  • Posts: 83
Voltages are off after smashup upgrade [solved]
« on: October 17, 2015, 12:02:36 PM »
Hey Bottleheads,

Unfortunately I'm back with another issue. After my smashup install, some of my voltages are way off. My kit is fully stock, and I will post photos shortly.
Here are some of my measurements. Thanks for taking a look :)

Location/Socket A voltage/socket C voltage/voltage in the manual 
The locations that were way off were noted with ********

IA/209.5/209.3/180-220

OA/207/207/150  ******

+regA/2.5/2.5/2.5

IB/207/206.7/150 *****

OB/64.9/65.3/45-75

KRegB/13.6/12.88/3-5 *****

BRegB/0/0/150 ******

+RegB/207.3/206/150 *****

Location/My measurement/Manuals measurement

B1/0/0

B2/207.2/150 ******

B3/13.6/3-5 *****

B4/0/0

B5/206.9/210

B6/12.9/3-5 *****
« Last Edit: October 17, 2015, 03:47:56 PM by RW »

Offline RW

  • Full Member
  • ***
  • Posts: 83
Re: Voltages are off after smashup upgrade
« Reply #1 on: October 17, 2015, 12:25:28 PM »
Please let me know if any more photos or measurements need to be posted. I also have a bunch of replacement parts incase anything needs to be swapped for testing. Thanks for taking a look.

Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 13893
Re: Voltages are off after smashup upgrade
« Reply #2 on: October 17, 2015, 01:53:41 PM »
How are pins 1 and 4 in terms of DC voltage on the octal socket?  With the bottom panel painted, you may have an issue where those are not being properly grounded.

Also, photos of the tops of the two PC boards could help, just to check the parts themselves.

From what I see, the C4S loads on each 4P1L are working OK, and it appears that the TL431 is receiving power, but not regulating.  The high voltage at each Kreg makes me wonder about swapped R1 resistors or a grounding issue at the octal socket.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline RW

  • Full Member
  • ***
  • Posts: 83
Re: Voltages are off after smashup upgrade
« Reply #3 on: October 17, 2015, 02:46:17 PM »
Hey CB,
At B1&B4 I have 0V. All contact points on the top plate were ground down to metal before the install. I did a continuity test and it all checked out. I just checked the resistors and they're in the right locations, as per the manual.
Thanks for lookin, your help is always appreciated.

Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 13893
Re: Voltages are off after smashup upgrade
« Reply #4 on: October 17, 2015, 02:51:40 PM »
Last step at the bottom of page 15.

-PB
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline RW

  • Full Member
  • ***
  • Posts: 83
Re: Voltages are off after smashup upgrade
« Reply #5 on: October 17, 2015, 03:47:07 PM »
Well, that was definitely it. Thank you very much for your help, and patience :)