Gas Gauge Circuit Issue

[BigD_ca]

I have a gas gauge that is identical to the following old post (the cct posted by chemelec):

https://www.electro-tech-online.com/threads/help-me-build-a-gas-gauge.34321/

The gauge works well but I can't get LED from the LM3914 to light up for some reason. Either I'm not changing the right resistors or I'm total off on what the issue is.

If anyone has a suggestion I'd appreciate your help.

Thanks!

 

[user_88]

... just something to check

I read someplace that tantalum capacitors are easily damaged ... due to the thin tantalum oxide film, or something of that nature.

Is your 1µ tantalum cap new or used?
Polarity must be correct ... apparently no second guesses. That would be + to terminal 3, and - to terminal 2.

 

[BigD_ca]

everything is new and i've checked all the connections...

 

[user_88]

How are you proto-typing?
Do you have a breadboard ... or are you using a pcb?
If breadboard ... can you post a picture? Sometimes the holes that look connected are not.

 

[BigD_ca]

I'm using a breadboard. I'll try shifting the LEDs or LM3914 on the board and see if that makes a difference. I'll post a pic later.