[werk_ag]

Hi Russell,


Since your displays isn't work nor with the RX nor with the WD units, try this:

* Download the latest WeatherDuino Pro2 PLUS software again.
* Completely remove the TFT_ILI9341 library, and copy the TFT_ILI9341 library supplied with on the software package.

Lets us know if that solves the problem.

[russellb]

Well, some developments, probably not very positive.

I went over the Rx board and reheated most, if not all of the solder joints, as some looked marginal
No change on reloading the software, 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
I took C5 out to check it wasn't short circuiting, and on reconnecting the voltage is now only 0.44v. I've hunted carefully for solder bridges, and no signs.

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,
From the 3.3v line to ground measures about 250 ohms. Does that sound reasonable? It would represent a current of about 130 mA which seems fair.
It certainly doesn't seem there is a major short circuit dragging the voltage down.

The absence (for practical purposes) of 3.3v would explain the wi-fi not starting, and I presume the BME280 and RTC would also fail,and hence the software would not run?

FWIW the 3.3v terminal on the Arduino board produces 3.3V.

Regards

Russell

[werk_ag]

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...

...
If you have a multimeter, try measure the output voltage of the 3.3V regulator.

...
I had already checked voltages, and 3.3 v seems OK.

...
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

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).

[russellb]

Thanks for the prompt response. I hadn't really considered using the Arduino 3.3v supply.
The 250 ohms was from 3.3v rail to ground, but of course with the regulator in circuit.

OK, so I've ordered  replacement AMS1117-3.3 regulators and some extra 100μF capacitors.
More news later in the week, I hope

[russellb]

Well, back after life getting in the way a little.

I replaced the AMS1117 and the C5 electro.
Voltage is now 3.32v, but  I notice the 3.3v regulator is quite warm after it has been running for a few minutes.

Display, with the "new" TFT is still blank white. The wi-fi is connecting and time is being set from NTP

Where to now, please?

[JT118]

Could I suggest you check the output from the power supply. I have had an original Davis power supply (rated at 9v) put out 17v and damage one of my boards, and I had symptoms similar to yours. The best power supplies I have found are off old routers / modems (available from ebay) or those from XP Power.

[werk_ag]

Well, back after life getting in the way a little.

I replaced the AMS1117 and the C5 electro.
Voltage is now 3.32v, but  I notice the 3.3v regulator is quite warm after it has been running for a few minutes.

Display, with the "new" TFT is still blank white. The wi-fi is connecting and time is being set from NTP

Where to now, please?

Something is not right, the regulator shouldn't get very hot.
Have you checked for any short between the 3.3V rail and GND before the installation of the new regulator?
Well, my best guess is that due to some reason IC1 becomes damaged, this IC is very sensitive to static.

If you wish, I can try to check what is happening with the board and eventually repair it (if necessary I will replace the IC1 at no cost). Just send it to me, together with the Meduino board and the TFT display. Let me know if this is good for you.