29-07-2018, 02:57
russellb Wrote:FWIW the 3.3v terminal on the Arduino board produces 3.3V.
Starting by the end. Don't even think in connecting the Meduino 3.3V pin to the board 3.3V rail, the Meduino will be damaged in seconds.
From post #20 some days ago...
(13-07-2018, 16:49)Werk_AG Wrote: ...
If you have a multimeter, try measure the output voltage of the 3.3V regulator.
(14-07-2018, 09:55)russellb Wrote: ...
I had already checked voltages, and 3.3 v seems OK.
(14-07-2018, 09:55)russellb Wrote: ...
so I decided to check voltages, and found that while the 9v and 5v lines were OK, the 3.3v was showing only 1.4v
(14-07-2018, 09:55)russellb Wrote: I presume this means that IC3 is cooked? I had noticed it hot earlier. Is it practicable to replace it? I can get an AMS1117-3.3v for $1,
Even without a hot air gun IC3 can easily be removed, but don't try doing it just by applying heat on all legs at the same time. Instead follow this procedure:
With and appropriate tool, cut the three small legs (IC3) as close to the chip as you can, then aptly heat to the large leg on the top and remove the IC, then gently apply heat to each of the three pads and remove the remaining of the IC legs.
Before welding the new IC3, check and double check if there isn't any short on the 3.3V rail. If there is a short, which I hope there isn't, then must probably the IC1 is damaged (this IC is very sensitive).