Hisense Model DH-35K1SJE5 does not switch on | Diagnostic Help Sought

Hi @drillbit

Is there also a power board in the unit?

No display is either a faulty control board or no power getting to the control board.

From the images you posted I can only see a step down power transformer (see 4th image you posted) where it shows 115V AC input and 10.5V AC output.

Check when power is connected that there's the correct voltage into the transformer and out of it.

If there are the correct input and output voltages measured at the transformer, then disconnect the power to the unit and check where the transformer output wires connect to, so that you can start checking what happened to it at that point e.g. if the cables end up on the power board then the board may be faulty, although I couldn't see any obviously visible component damage on the board. Faulty Power button idk?

If there is no input voltage at the transformer, then disconnect the power to the unit and check where the input cables to the transformer connect to. It may be a faulty power cord for example

If there's an input voltage at the transformer and no output voltage, then the transformer is faulty.

Bit roundabout way of testing, but without a wiring diagram or a service manual (I couldn't find either one) it's about the best that I can think to do.