XXV Sampson power up issues

[beatnbronco]

👍

 

[beatnbronco]

I cleaned the board up very good around the PS drivers and installed new one's. I have a shark fin sign wave on 4/5/6 PS Fet of each group. 1/2/3 PS Fets only show very little signal at all. Checking schematics to find out what could be causing the same PS Fets of each group to have the same issue

 

[Perry Babin]

I'm not sure what the scope is telling us. The overall shape of the waveform is what I'd expect.

Where is ground? What is the yellow line?

With exactly the same settings, post the waveforms on the output pins of the driver IC.

 

[beatnbronco]

That's OK.

Connect it across the gate and source terminals and while it's connected, check the gate signal .Confirm that all are the same.

If you mount it on a piece of header (or similar) and put a small amount of back force on the header, it will make a good enough connection to check them without soldering.

The waveform should look something like the attached waveform. Use the scope in the same settings, and DC coupling. Align the trace to the reference line before starting.

I was performing this test we were trying before I was chasing a possible short in the PS drivers. Using a 0.1uF capacitor between gate and source pads. The yellow line is Trigger from my understanding and ground is amp ground input coming from power supply. I'll get the next pics and testing done as soon as I can. Gall bladder is coming out in the morning. Thanks for the help