Shunt Regulator Upgrade Voltage Checks [resolved]

[duman]

Hi,

My Steremour II has been happily running for almost 3 years, including the last 6 months with the DC Filament Supply upgrade.

I just installed the Shunt Regulator upgrade and the voltage checks don't match the manual.  In particular:

IA: fluctuates during measurement between 382-388 VDC
OA: fluctuates during measurement between 304-320 VDC
KregA: fluctuates during measurement between 368-373 VDC
IB: fluctuates during measurement between 385-387 VDC
OB: fluctuates during measurement between 140-205 VDC
KregB: fluctuates during measurement between 6.3-7.2 VDC

None of the LEDs on the big board are lit.  On the small board, the B-side LEDs are lit and the A-side LEDs are flashing.

I've triple-checked the wiring and solder joints.  Any thoughts appreciated!

 

[Paul Birkeland]

KregA: fluctuates during measurement between 368-373 VDC

That is a very improbable result.  Can you take the board off and show some photos of the bottom and the 9 pin socket wiring under the board?

Also there's no need to bend the wires passing through the board, and doing that can make them very hard to remove.

 

[duman]

Thanks Paul, will do.  And thanks also for the wiring tip!

 

[duman]

Here are pics of the underside of the board and the two small tube sockets.  Thanks very much for any assistance!

 

[Paul Birkeland]

Leaded solder and a very hot iron are required to get good results with our kits. 
https://www.youtube.com/watch?v=EN16Pi7pcfk

 

[duman]

Success!!  I reflowed all the joints at a higher heat and am listening to sweet music once again.

IA: 376 VDC
OA: 297 VDC
KregA: 4.18 VDC
IB: 376 VDC
OB: 299 VDC
KregB: 4.75 VDC

Thank you Paul!