Value keeps jumping around

[Synapsis]

I put in a new heat bedbecause the last one had a couple of defects.
I did the setup as always from David Crocker's Solutions blog

Now when I try at the end G30 S-1 it stops where I had calabrated it, but instead of giving me 534 as before it starts flashing and
the value jumps from 999 768 000. Tried different spots and dfifferent materials it always stops at 2.41.
If i move the bed cloeser by Z-0.1 it stops flashing and reads 534.

Any ideas as to why??

[dc42]

If you are getting values higher than about 535 then that usually means either you have a bad ground connection to the sensor, or you have direct bright sunlight reflecting off the bed into the phototransistor. If the cause is direct bright sunlight, then the LED will blink at a constant (fast) rate.

[Synapsis]

Thanks David probaly the ground connection as it was dark and to be honest I redid the wiring.

Now without doing anything its working but I ill check the connection.