It is not good when I get this error on one of my power supplies.
It is related to the network interface and I sort of need that.
It is not a bad connection in the wires connecting it.
The main chip on the interface card is a BGA, this is not easy to measure one. I wonder it it is worth heating the chip.
That was something I did really early on. It started on this maybe a week ago, but only occasionally. It is used when I test USB or 12V powered chargers and it meant a lot of failed tests. My first idea was a bad connection inside the power supply, but opening it up and reseating all connectors did not fix, it made it permanent.
I tried another interface card (I have another power supply in the same series, but with different output voltages) and it worked partially, it obvious was not programmed to match this supply.
The network card:
As I see it there is not much I can do on that card, maybe checking the optocouplers (IC6 & IC7) and maybe heating IC2 up to 250°C (That is a last try). It may also be possible to buy a spare part from TTI.
The power supply works fine with the network interface disconnected, but I do not have much use for a standalone supply.
The main processor card:
There are 3 more cards in the supply, but I did not take pictures of them.
Look like a happy ending. I was looking in the wrong place, even though the network interface was the only part that failed, it was not the problem.
The network interface is powered from this board:
That blue capacitor looks like it has a convex top (That is a very bad sign), at check with an oscilloscope on the regulator input:
The regulator is supposed to deliver 5V out, but that is a bit difficult with below 4V input.
After taking it out I checked it, it had 1000uF as it is supposed to have, but ESR was 22ohm, it was supposed to be below 1ohm.
After replacing that capacitor the network interface worked again. Regular USB charger testing will resume tomorrow.