New main board assembly but Zero VSS reading

[sy9dok]

Hello all
I have received a brand new main board kit from UpTech today and assembled it . The rf board is an older Low bands one .
I face some problems .
In the Power/ VSS screen the reading is always zero (0) for the VSS . Same for Usb power or my external 12v pack .Besides the zero VSS reading , RF power output on my external MFJ bridge shows exactly the same power as my trusdx. (4.9w)

Any suggestions please ?
TU 73 , Geo

[dl6sez]

Hello OM,

(tr)uSDX has no VSS reading!

73 de Chris

[wb9oqb]

HI Geo,

The Trusdx certainly does have a Power/VSS option in the menu.
The Power/VSS works on both my classic, and lo band Trusdx.
In fact that is what I used for checking my voltage when calculating my power into the unit.
If it is showing 0 volts when transmitting cw I would look for cold solder joints and or bridges.
If that doesn't fix it others on this forum will usually have helpful suggestions.

Mike

[rmoravcik]

Hello all,

Isn't VSS measured by INA219 over I2C?

Is efficency showing some value?

INA219 is measuring current consunption and supply voltage of PA stage. FW probably then use this value to calculate PA efficency.

Regards,
Roman

[dl6sez]

Hello OMs,

sorry you are right it has also PWR/Vss reading as last option in the menue
If it does not read anything like Vss or efficiency your INA219 U1 on RF board, as OM Roman said, could be damaged. I first would do a full reset by pressing tuning knob while connecting to power and if this doesn't help i would reload the firmware again before as a last step, try to replace the INA219.

73 de Chris

[sy9dok]

thank you all gentlemen. It was a cold solder joint as pointed in this thread. Everything fine now.
73!