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

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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…

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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.

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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!

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