I have had my multiwii 328p board running for a few weeks, but today it has developed a fault with the 3.3v regulator.. seems like its fried, i have checked the pad just above it for 3.3v and its no longer present, and the 3.3v led no longer lights, the board boots up ,and connects to multiwii.conf. anyone like to advise on how to repair it i have a soldering iron and can remove it no problem, is this a common problem with the boards ?
thanks Al...
multiwii 328p hobbyking loss of 3.3v
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handsomejackuk
- Posts: 97
- Joined: Mon Sep 08, 2014 12:25 am
Re: multiwii 328p hobbyking loss of 3.3v
First- is there a short on the 3.3V line? Caps can short internally and the regulator will shut down.
Use your Ohmmeter across the 3.3 to common (ground) to check. Should be a few kiloOhms.
If NO shorts then try replacing the 3.3V regulator.
If you see a short then start lifting caps until the short is removed.
Yes, the Atmega will boot since its power from 5V but you'll not get any sensors since they are powered from 3.3V.
In the mean time get another board on order in case this one is not repairable and to have a spare (also good to make measurements on for comparing to the bad board).
Use your Ohmmeter across the 3.3 to common (ground) to check. Should be a few kiloOhms.
If NO shorts then try replacing the 3.3V regulator.
If you see a short then start lifting caps until the short is removed.
Yes, the Atmega will boot since its power from 5V but you'll not get any sensors since they are powered from 3.3V.
In the mean time get another board on order in case this one is not repairable and to have a spare (also good to make measurements on for comparing to the bad board).
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handsomejackuk
- Posts: 97
- Joined: Mon Sep 08, 2014 12:25 am
Re: multiwii 328p hobbyking loss of 3.3v
Waltr...
looks like there is a short across the 3.3v line to Gnd....
It did occur to me whether i could cut the output track from the regulator, and supply an external 3.3v regualted source from the I2c pins...if this then works, I can lift the said faulty regulator... looks like all the sensors are fed from the 3.3v line.. I have been in touch with hobbyking for a refund, so dont want to remove any components yet they may need the board back...
looks like there is a short across the 3.3v line to Gnd....
It did occur to me whether i could cut the output track from the regulator, and supply an external 3.3v regualted source from the I2c pins...if this then works, I can lift the said faulty regulator... looks like all the sensors are fed from the 3.3v line.. I have been in touch with hobbyking for a refund, so dont want to remove any components yet they may need the board back...
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handsomejackuk
- Posts: 97
- Joined: Mon Sep 08, 2014 12:25 am
Re: multiwii 328p hobbyking loss of 3.3v
the regulator feels very hot to the touch too.. so suspect its at fault... would you know what regulator it is as i could always replace it for an equivalent..
thanks
Al.
thanks
Al.
Re: multiwii 328p hobbyking loss of 3.3v
If you found a Short I said to:
If you see a short then start lifting caps until the short is removed.
Probably it is one of the Tantalum caps (the yellow ones).
Unsolder the ones you measure a short across until the short goes away. The last cap you un-soldered is the bad one. Replace it and solder all the other caps back. Re-test the regulator output.
It is probably NOT the regulator. It is getting hot since its output is shorted.
If you see a short then start lifting caps until the short is removed.
Probably it is one of the Tantalum caps (the yellow ones).
Unsolder the ones you measure a short across until the short goes away. The last cap you un-soldered is the bad one. Replace it and solder all the other caps back. Re-test the regulator output.
It is probably NOT the regulator. It is getting hot since its output is shorted.