Repair of Accurite Indoor/Outdoor Wireless Thermometer

[xrunner]

This small post isn't so much for the regulars here, it's more for a consumer to find Googling some day, wishing to repair a fault such as this one had. This is an Accurite Model 00782.

The problem was that the outdoor temp was displaying ~106 F in a room that was nowhere near that temperature (should have been near 80 F). I have had this for years and I noticed it gradual displaying too high a temp for the outdoor sensor.

After changing the batteries, and not changing the results, I decided to take apart the outdoor sensor. Upon inspection I found that some compound had "grown" between some unused SMD jumper pads, probably causing an error in the reading. I scrubbed the area with alcohol and removed the chemical growth. That fixed the problem. It's certainly back within specifications for such a consumer device which is probably +/- 10% or so.

So, for you out there that aren't familiar with trying to fix electronics, you might consider taking apart the item you are about to throw away, and simply inspect it. Stick to small battery powered items like this one and other things such as toys. Hey it's worth a try isn't it? 

[onesixright]

Upon inspection I found that some compound had "grown" between some unused SMD jumper pads, probably causing an error in the reading. I scrubbed the area with alcohol and removed the chemical growth.

Interesting 😀 Any idea what that is and what caused it?

[NiHaoMike]

Looks like it was caused by moisture since it's the outdoor sensor. Add a coat of paint or super glue to seal them up.

[xrunner]

Any idea what that is and what caused it?

No idea at all. I've used it here and there for years. The odd thing is that the area where the "growth" occurred is no different than the rest of the board as far as I can tell. No idea why the growth was only in that area.

Looks like it was caused by moisture since it's the outdoor sensor. Add a coat of paint or super glue to seal them up.

Possibly, I used to have it in the attic, so at least high humidity. I went ahead and opened up the indoor sensor to inspect - no issues. So, good to go for a few more years. 

[onesixright]

Any idea what that is and what caused it?

No idea at all. I've used it here and there for years. The odd thing is that the area where the "growth" occurred is no different than the rest of the board as far as I can tell. No idea why the growth was only in that area.

But it looks like a chemical reaction, just on moist? 

[SeanB]

Probably an area with flux residue that attracted moisture from the air. Cleaned the board and got rid of it, though it really should have a small bit of masking applied to the LCD pads and then conformal coat the rest of the board with a few light coats of spray lacquer.