HP97 The journey begins

[teenix]

(05-04-2019 09:16 AM)Harald Wrote:  Hi Tony,

That is good news indeed!
I doubt the shielded coil will improve things a lot. It Is more likely to be a layout issue. If you like you can post the schematic and layout of the power supply section, maybe we can spot a problem.

Cheers,
Harald

Attached is the relevant part of the PCB for the PSU. Under the board is just signal paths.

GND comes in from the far left of the PCB direct to the LP2950 GND pin.

The marked 5V and GND points feed each circuit chip in a serial fashion with decoupling caps placed just prior to reaching the respective chip.

The LP2950 Vin is under the PCB from the yellow tracks.


cheers

Tony