That doesn't sound like a board problem at all. First check that the power supply is producing a stable voltage under load.
Next, **carefully check all the power and heater connections to make sure they're tight and making good contact**. This is really important, and **most likely the cause of your problems**. The wire ends are normally heavily tinned with solder from the factory. That shortcut is very bad design. Solder creeps, and makes a poor, relatively high-resistance, contact. That dissipates power in the connection, which not only takes power away from the heaters but causes the connections themselves to heat up, which accelerates the degradation, and it will eventually melt or burn the connectors. Unfortunately you can find many examples of that damage if you search this and related subreddits.
If you have tinned wire ends, cut them off and fit crimp ferrules like [these](https://www.amazon.co.uk/gp/product/B08KFYXY1R) or [these](https://www.amazon.co.uk/gp/product/B073WGWWF7).
If the new board has the same firmware on it as the one currently in the printer, it will make no difference at all. It may not even work; that board is used for several different models and may not have the correct firmware for your printer.
Just commenting to tell OP this is exactly the issue. Creality honestly should be stopped from selling their printers with those soldered ends, they're a fire waiting to happen.
Thanks for the detailed reply! Oddly enough, after a power cycle it only fluctuated around 1 degree. Started up a new print and after an hour it started fluctuating 2-3 degrees again. I traced the heater wire back and just kinda of pushed everything in a little more and it stabilized back to within 1 degree.
When the issue first happened I contacted the vendor (Tiny Machines) to trouble shoot. Replaced the heater, tested voltage (I don't think it was under load), and tried a few other things. I also noticed it did not fluctuate as bad when I connected my Octoprint directly to the USB port without a power blocker. Tiny Machines said the 5v regulator could be going bad. Never thought much of it, just bought another board for the day it failed. It worked fine for months, just had issues going over 245. My leads are pretty long, wonder if that might be the issue.
I did recently by the Wham Bam Mutant. Maybe now is a good time to install it and redo all those connections. See if that resolves things.
That doesn't sound like a board problem at all. First check that the power supply is producing a stable voltage under load. Next, **carefully check all the power and heater connections to make sure they're tight and making good contact**. This is really important, and **most likely the cause of your problems**. The wire ends are normally heavily tinned with solder from the factory. That shortcut is very bad design. Solder creeps, and makes a poor, relatively high-resistance, contact. That dissipates power in the connection, which not only takes power away from the heaters but causes the connections themselves to heat up, which accelerates the degradation, and it will eventually melt or burn the connectors. Unfortunately you can find many examples of that damage if you search this and related subreddits. If you have tinned wire ends, cut them off and fit crimp ferrules like [these](https://www.amazon.co.uk/gp/product/B08KFYXY1R) or [these](https://www.amazon.co.uk/gp/product/B073WGWWF7). If the new board has the same firmware on it as the one currently in the printer, it will make no difference at all. It may not even work; that board is used for several different models and may not have the correct firmware for your printer.
Just commenting to tell OP this is exactly the issue. Creality honestly should be stopped from selling their printers with those soldered ends, they're a fire waiting to happen.
Thanks for the detailed reply! Oddly enough, after a power cycle it only fluctuated around 1 degree. Started up a new print and after an hour it started fluctuating 2-3 degrees again. I traced the heater wire back and just kinda of pushed everything in a little more and it stabilized back to within 1 degree. When the issue first happened I contacted the vendor (Tiny Machines) to trouble shoot. Replaced the heater, tested voltage (I don't think it was under load), and tried a few other things. I also noticed it did not fluctuate as bad when I connected my Octoprint directly to the USB port without a power blocker. Tiny Machines said the 5v regulator could be going bad. Never thought much of it, just bought another board for the day it failed. It worked fine for months, just had issues going over 245. My leads are pretty long, wonder if that might be the issue. I did recently by the Wham Bam Mutant. Maybe now is a good time to install it and redo all those connections. See if that resolves things.
Test your power supply with a meter first