Question PMS lite not suppling 5v

[void]

My Pms Lite will not supply 5v on the 5v line but all the other lines are correct. Instead the 5v line is suppling 3.9v

 

[atkfromabove]

My Pms Lite will not supply 5v on the 5v line but all the other lines are correct. Instead the 5v line is suppling 3.9v

Do you have the 5v hooked up to a screen? Is the screen not coming on?

 

[void]

With or without a screen connected is supplies the same 3.9v

 

[Retro95]

I ran into a similar issue myself when building my first ashida. All voltage rails worked except for 5v.

Your board looks pretty caked in flux from soldering. Have you tried deep cleaning the board with toothbrush and 99% IPA?

Flux is partially conductive and can cause partial shorts if the flux puddle connects to a via or component that is on a different voltage rail, or even ground. This can cause voltage drops and unwanted device functionality.

 

[void]

I clean up the board and the problem is still there. I checked the voltages again and the 5v line is showing about 3.64V, which is the same voltage that i get from checking the fan+. I checked on the back side of the board and it is not bridging.

 

[void]

I think this chip is not working

The two pins circled in red are giving the same voltage. Im pretty sure that the pin on the right should be giving 5 volts, but instead its giving the same 3.64v

 

[Retro95]

What temperature is your soldering iron set to?

 

[void]

345 C

 

[Retro95]

Are you using a standard 5v fan?

Try unsoldering the fan wires, cleaning that section of the board with IPA and see if your voltage stabilizes.

 

[void]

Yes i am using a 5v fan, I unsoldered the fan and cleaned it with IPA and the voltage is still 3.64

 

[Customledmods]

Can you upload a full clear picture

 

[void]

 

[Customledmods]

Disconnect everything only leave charge ,gnd, button and the batteries. Then make sure the batteries are charged power it up and test the voltages on each of the pads.

 

[void]

3.3v is 3.3v, 1v is 1v, 1.15v is 1.16v, 1.8v is 1.06v, 5v is 3.63v

 

[Customledmods]

what voltage the batteries ?

 

[void]

3.46v

 

[Customledmods]

Charge them do you have 2 connected ?

 

[atkfromabove]

This looks a little funky. Not sure if it could be causing the issue or not

 

[void]

I have 4 batteries connected

 

[Customledmods]

I have 4 batteries connected

You can use 1 or 2 just for testing make sure they are charged tho.