STC 1000 Display Issue

[blk84]

I'm having an issue with my STC1000 display. It was working perfectly in my chest freezer as a temperature controller for both fermentation control and keg serving temps. I turned it off when I didn't need it a couple weeks ago and when I plugged it back in and turned it on Saturday for a fermentation I noticed the bottom left part of the LED for the ones place was missing. In fact, there is a new LED line to the left of the tens place-so it looks like it's out of place. Also, the tenth's place is missing the bottom horizontal LED. I confirmed these are missing by trying to reprogram the set temp. The actual temp of the chamber is 18.3C but as you can see from the picture below it looks like 19.7.

The compressor is kicking on when needed, the display is just wrong. I took the unit apart and checked all of the connections and everything seems to be tight. Anybody have any ideas? Is the controller just going bad?

Sorry for the sideways pic- it's
Thanks for any thoughts or leads!

 

[number40fan]

Mine did the same thing for a short time, but started working correctly shortly after and hasn't messed up since. But, I only had one leg of the second number that was messed up. Give it some time and see what happens.

 

[mattd2]

DId you just unplug it from the wall to turn it off? Maybe try turning it off/on by holding the off button for 3 seconds.
Seems like the microcontroller on the borard is either sending the wrong message to the display, or there is some damage to the traces on the board.

 

[blk84]

Thanks for your thoughts guys. I turned off the unit with the power button and I also unplugged it from the outlet without any change. One thing I found interesting was when I powered down/ unplugged the whole setup and waited 15 minutes before powering it up again the F1 set point (18.3C) did not reset. I'm far from fluent in electronics but that seems odd- is there some sort of memory/power storage area in the controller?

 

[alphaomega]

Yes. The settings are stored in EEPROM, so that they should be retained.
My $0.05 would be to yank power without turning it off first.
Also, go through the menus, try adjusting setpoint (change the value, like a lot), what happens? Is display messed up when changing SP and showing menus as well?

 

[blk84]

Tried unplugging without powering down- no change

Went through menus and changed the values as you suggested and it now looks like those two rogue LEDs are brighter than yesterday however When I get to a number that requires the rogue position to be lit it is the same intensity as the rest of the number. The whole issue seems to have started when I was programming the set point up from refrigeration temp to fermentation temp.

I have a new controller on order but it still seems to be controlling temperature correctly, just a display issue.

 

[alphaomega]

Tried unplugging without powering down- no change

Went through menus and changed the values as you suggested and it now looks like those two rogue LEDs are brighter than yesterday however When I get to a number that requires the rogue position to be lit it is the same intensity as the rest of the number. The whole issue seems to have started when I was programming the set point up from refrigeration temp to fermentation temp.

I have a new controller on order but it still seems to be controlling temperature correctly, just a display issue.

Yes, it most likely is an display issue. And a weird one.
Looking at your pic, I'd say it is trying to display '18.7'. I've been lookong at the schematic, and what is interesting is that it is LED number 5 that is wrong on all four positions. The weird thing to me is the '8' being displayed as '9'. That means the led is not constant on, but rather inverted. This suggests that it is not hardware failure, but rather software.

Cheers!

 

[william_shakes_beer]

what you need to do is walk over to the cotnroller and very softly whisper " if you don't start working again I'll replace you with something that does"

 

[mattd2]

what you need to do is walk over to the cotnroller and very softly whisper " if you don't start working again I'll flash you"

FTFY
But seriously if it is a software issue and it is a STC1000+ compatable unit then this would be an option right.