@Hugo Holden Thanks for the input man. But I still belive my measument is fine. Here is why...
I have now tested the other 7805 Voltage regulator and it gives me 5V with @daver2 resistor trick. This is the Voltage regulator locacated in the middle. So I guess this regulator is good!
The regulator I suspect is bad still gives med those -0,9V witch @daver2 says is impossible. I have notice the regulator getting a bit warm and draws 2.5amps. So Im still voting for a shooted regulator.
Thanks for posting man. Yeah l will try that. Iĺl report back.
In your post #15 you measured little voltage out of both of the 5V regulators.
Now you are saying that they are both disconnected, and the one in the middle has recovered a normal output voltage on testing (by implication it means that this one is overloaded by a short in the external circuitry). But is its output still normal when reconnected and powering the PCB ? because it was not when you first tested it.
The other regulator on the end has failed, it would appear, and needs to be replaced, but this is the one (from your previous photos) where you were experimenting connecting a power supply to it with incorrect connections that might have damaged it. So when you replace it , it may or may not be operational as it could be overloaded from an issue in the circuit it is powering. So you still have a few issues to sort out here. What I am saying is that while you are voting for a "shooted" regulator at this point, it may have been you who shooted it and the underlying initial faults possibly still remain. So be prepared for that.