Question PMS lite not suppling 5v
- Thread starter void
- Start date
Fully charged 4.2v
That's odd
Maybe someone else can step in and help identify this component, also I would inspect the full board to make sure there’s no shorts or excess solder where it shouldn’t be.
Oops i forgot to mention for him to check for shorts in the ones circled red and someone help identify this one here. It’s from his earlier post he made
Yeah that component is a bit trickier to identify because of the SMD marking. I couldn't find any spec sheets online for it.
Silly question for @void; have you tried disconnecting all batteries from PMS and turning it on and off half a dozen times?
At one point when I was building my first ashida it just stopped booting entirely. I was getting weird voltage readings across all my rails, I pulled the batteries out of it and power cycled it quite a few times. Put the batteries back in and it has worked without issue since then.
It's very rare but sometimes the circuits on a board need to be entirely discharged before the circuit behaves normally again.
Remove the batteries, and check your voltage from 5v/3.3v to GND. If you read anything higher than 0, cycle the power switch until you read 0.
It could be saturation, yeah. A full drain is absolutely worth a shot
Do you have continuity between the 5v pad and the B+ pad on the PMS? The 5v reg might be shorted
void
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I do have continuity between b+ and 5v
I just checked B+ against 5v on a spare PMS LITE I have and got OL (no continuity)
You've got a short somewhere that's creating either a voltage drop, or causing one of the voltage regulators to not function properly.
The PMS LITE is closed source so there are no schematics available to help you troubleshoot this down an SMD component level.
Last thing I can think of would be to unsolder every wire from it, and basically bathe that puppy in 99% IPA and SCRUB SCRUB SCRUB. Half a dozen times at least. If that doesn't resolve your issue I think at this point you're better off buying a new board.
Sorry buddy );
You've got a short somewhere that's creating either a voltage drop, or causing one of the voltage regulators to not function properly.
The PMS LITE is closed source so there are no schematics available to help you troubleshoot this down an SMD component level.
Last thing I can think of would be to unsolder every wire from it, and basically bathe that puppy in 99% IPA and SCRUB SCRUB SCRUB. Half a dozen times at least. If that doesn't resolve your issue I think at this point you're better off buying a new board.
Sorry buddy );
Removing and replacing the 5v regulator is an option as well, but yeah I'd give it a good clean first and inspect the 5v reg for a visible short between VIN and VOUT