Quantcast

Eggtimer LCD not working

The Rocketry Forum

Help Support The Rocketry Forum:

askrob

Active Member
Joined
Jul 24, 2020
Messages
26
Reaction score
13
Hi all,
I have an Eggtimer LCD receiver kit. I had it working, but somehow, still not sure how, the battery terminals shorted. Before the short, I measured the power regulators and they were at 5v and 3.3v. Which should be correct. After the short, I noticed that the 3.3v regulator was now measuring 0.5v. I replaced the 3.3v regulator and the associated capacitor, and there was no change. I assume I'm measuring them correctly.

Also, I noticed that the capacitor connection that is next to the power regulator has continuity between the two holes. This seems odd to me, as the other 2 capacitors don't do the same thing. I am not an electrical engineer, and I am very perplexed what's going on.

5 volt regulator
PXL_20201016_011701450.jpg

3.3v regulator
PXL_20201016_011718740.jpg

Continuity between holes for capacitor.
PXL_20201014_192228959.jpg
 

cerving

Owner, Eggtimer Rocketry
TRF Sponsor
TRF Supporter
Joined
Feb 3, 2012
Messages
3,887
Reaction score
1,084
That's the 3.3V output... you have a dead short, which is why the regulator isn't reading correctly. It's undoubtedly blown... which would make sense, since the previous 3.3V regulator was blown too, and the source of the short was not corrected. At this point it's going to be difficult to troubleshoot... you could keep removing active components (RF module, processor) and possibly replacing regulators until you find the problem.
 
Top