Anet A8 bed temp issue

My first mistake was telling my grandchild I could print a giant rainbow unicorn.

Halfway through the print it errored out and shut it down. I look at the com window and the bed temp suddenly went to -55. I’ve seen that usually i reseat the connectors and its fine. This time it wouldn’t clear. So on the main board i swapped the hot end and bed thermistor plugs, restarted and the problem moved. So definitely the thermocouple path.

Id had enough of this so i decided to solder the tc cables down. Which was nearly a good idea.

To be honest id have done it sooner but im lazy. I didnt jive with the look of that though. So i took off the connector and cleaned it up a bit

When I started into that i noticed my first soldering was while the system was powered. Once it was reassembled it now gives me a constant temp of 99.

Which I assure you its not. Swapping the TC cables does NOT move the problem. So now the issue i think is in the main board. But the connection just has a current limiting resistor and a cap

So Im thinking i may have blown the pin? On the uC

Also, T56 is at 4.79V and t54 is at 2.7v no matter which tc is in there.
Something is dragging that voltage down

Confirmed there is a short to ground on that test point even without a tc plugged in.

Sounds like the pin on the uC to me. Is there anyone else with an idea or…

Hey, I’ve robbed a few parts off of my (now unused) A8, but I do have a working heated bed and control board, if that will get you to happy rainbow unicorn land faster.

Could potentially be the capacitor. I’d remove it and see if it is still shorted. But yeah, likely the pin is fried.

Well I was running the 1.5v so I have a 1.7v board on the way. It has a replaceable fuse!

Did the 1.7v board come in yet? Wondering minds want to know. 8^)