[scartail]

Hi all,

While I was fiddling around trying to get the inj leds to work, I blew C16 on v0.4.3.c board. Now I have some questions.

1. What is it's function? While searching the info on C16, some wrote that it was a "transient protection" and another referred to as a "filter cap."

2. Does it have to be a polarized cap? ref. https://cdn.hackaday.io/files/441318880 ... _schem.png I've read that a non-polarized cap can replace a polarized cap, but not the other way around. I can bastardized something a used cap from old electronics, and only have non-polarized caps.

3. Can I jump it? No cap... and have minimal risk?

Bottom line, I want to troubleshoot a little more before ordering parts; save on shipping and all. Instead of just buying the one damage component I see, and later find something else wrong.

Thanks in advance.

[pazi88]

You can test the board without C16. No problem. Just remember to add it before start actually using the speeduino.

[scartail]

thanks for the response.

so i can apply 12v directly to the inj and ign circuit without any issues?

[Dagaz_Psi]

Yes you can apply power to +12v to the power post on the speeduino. the cap is there to smooth out voltage spikes so if u are using just a battery there should not be an issue.

[scartail]

Hey guys,

I found some caps on amazon and was able to get power back to the board (v0.4.3). However, I'm faced with another problem.

I only get ~3.6v out of pin 3 of the voltage regulator (LM2940T-5.0). How should I interpret this? Is this a fault of the regulator itself or the components in the circuit? Here's a ref diagram. https://cdn.hackaday.io/files/441318880 ... _schem.png

[Dagaz_Psi]

Whats your voltage reading after the varisistor (14D220K) i think its named u2 on the board?

[scartail]

Whats your voltage reading after the varisistor (14D220K) i think its named u2 on the board?

Dagaz_Psi, I get 14v. My 12vraw is 14v too. And at the regulator pin 1, I get 13.7v. What do you think?

[Dagaz_Psi]

I had a board laying around so i desolderd cap16 and still had 5v. I also did some mesaruing on a new lm2940 5v and i got 8 volts out off that one without any caps or diodes.
can you desolder the ldo?

[scartail]

I had a board laying around so i desolderd cap16 and still had 5v. I also did some mesaruing on a new lm2940 5v and i got 8 volts out off that one without any caps or diodes.
can you desolder the ldo?

Do you mean remove lm2940? and test it out off board?

[Dagaz_Psi]

Yes