Bed jumps from 82-95* every time... misses the whole range

Hey all, i am having an issue with my temperature reading on my bed, it jumps from 87* to 97* every time it warms up, i think its either a problem with the melzi board, or a firmware setting because i changed my bed heater entirely, new thermistor and everything, and its the same symptoms, seems to read relatively accurately except that range... any suggestions?

I have tried 2 different beds, happened with my old PCB and my new Silicone heat pad.

i also tried changing the thermistor values and doing a PID, nothing helps... i wouldn't be surprised if this crappy melzi board is the cause... but i'd rather not spend $100+ (and a week to try to figure it all out) for a ramps setup.

Never worked with the melzi board. what printer is it on? and could you post the firmware to pastebin, then copy the address and post it here?

Dueling wrote:Never worked with the melzi board. what printer is it on? and could you post the firmware to pastebin, then copy the address and post it here?

its an aliexpress acrylic, i don't have a full firmware, i just use Gcodes to update it because i am afraid to wipe out any changes if i start with a fresh firmware. TBH the firmware scares the crap out of me, i hate coding.

this is the printer
paste this in the aliexpress search box 32357171936  (it wont let me post links for 7 days, forum limitation?...)

And as mentiond i changed the heated bed, i also printed a new x carriage and put an e3d lite6 on

well it looks like you may have a bad capacitor as stated here 3/4 way down the page

here is how to test it.

and it looks like its based in merlin, so it is quite easy to mod. you just have to know which tab to go to, and read everything on the page.
Nice thing about firmware is, you can't cook your board (if you stay in the right tab). And as long as you save a previous copy, reverting is just a flash away.

so basically save my pennies and buy a ramps, that's more or less what i expected.

found a whole ramps setup on aliexpress for like $45.. so i ordered that, so i guess the ole printer goes under the knife yet again, the only original part left will be the frame, and the motors. But I've learned a lot, which s why i bought a cheap one, wanted to learn how they actually work before investing in a decent one... one of my pet peeves is people who go out and buy expensive equipment that drives its self but they don't really understand how it works, they just throw money at it and have someone else fix it every time its not working properly.