Inconsistent build plate temps

not expecting perfect heating across the build plate but i seem to have uncovered a “dead spot”;
PLA printing , heat plate 60 degrees C; about non-stop printing for the past two months;
printer is a Delta (FLSUN V400);
build plate 300 mm around ;
all of a sudden my prints were failing , tried a number of print g-codes that were all working fine before;
then i noticed that the prints that were failing had large xy footprints and were failing in about the same place on the build plate;seems adhesion issue;
so i tried moving the model in Cura to the far edge of the build plate away from the failing spot ;
presto, print succeeded;
then i touched the suspect area and it was indeed cooler than the other build plate spots;
it appears to be around 2 inches in diameter;
i can continue to move the models in Cura away from that spot realizing that i have effectively shrunk my build plate and taken some models off the table
OR i can try to address the problem physically;
here is where the drama might start;
i have no idea where to start to fix this nor what is under that hot plate;
ideas ?
TIA

What sort of heat element does it have?

This certainly seems odd,

All of my delta printers have a silicone heating pad that they use, so it seems odd that one section would kick the bucket like that. Have you tried contacting FLSUNN directly, even if you don’t end up getting replacement bed from them they may have further suggestions for you as to what kind of stuff you could try.

Thanks,
Matthew

If only one area is affected there must be a segmented heat element. Could be a broken or burned out wire in the element or in the connecting wire bundle.

If you are using the stock bed heater, use a laser thermometer to check your bed temps. I have an Ender 5 Plus that was doing the same thing as what you described. I found that I was having temperature differences by at least 10 degrees C. I replaced the stock bed heater with a Keenovo bed heater and their AC power source so the printer doesn’t have to heat it up. I am reaching 60 degrees in a small fraction of the time, and I also have consistent temps all across the build plate. If you feel like Keenovo is too high priced for you, there are other similar heaters out there, but I cannot speak on their dependability, accuracy, or reliability.

hmmm, i appreciate your response; i found that heater bed on amazon:
https://www.amazon.com/approx-KEENOVO-Universal-Flexible-Silicone/dp/B00V81ZI70

for the moment i am just moving the models in cura away from the problem area;
in doing so i usually move the models off the origin (xy 0,0) to -25, 25 ( an inch toward 2 o’clock);
it in general has worked as my models tend to be more vertical than x-y intensive;
BUT i did encounter ‘rough edges’ brim and model on first layers on that new far edge
so there seems to be another spot on the build plate not being consistently heated by the heater bed;
i will use your option if the base issue gets worse or i just of it ;
the amazon unit i referenced is the exact size i need 300 mm x 300 mm and have added it to my amazon cart (specs say 750 watts ! if my printer is rated at 450 watts that just means mating it with a new heater bed will just heat slower than a full 750, right ?)
oopsi, just noticed that heater pad is rectangular, my delta printer has round beds;
speculate with me here please, my printer (FLSUN V400) came with an extra thermistor (but not a spare nozzle !) is it possible that the manufacturer knows this consistent bed heating is a knownn issue with this printer , thus sending a spare ?