I'm hoping someone has a idea on what to do to fix this.

My YL and I built the Bitx40 with the Raduino three nights ago. It was working fine till today I?
unplugged the Radunio to mount it in a case. When I hooked it back up the display will not light up and only a few clicks in the speaker. The unit will still key with no output power. I checked the voltage and it still has 12.58 volts at the Radunio. I also hooked the Radunio to the PC to check if it was dead. It was able to be recognized and the ardunio software was able to talk to it.?

Any ideas what might have happened? All connections look ok.?

Thanks in advance,
Jamie Dean - KW4XR
Morganton, NC USA

Make sure the the 16-pin connector to the display is positioned correctly
(you can easily shift it one position by mistake)

73 Allard PE1NWL

I did check that. It was right.? When hooked to the PC the display lights up but on the bitx40 it seems dead. The red power light it not lighting up under the display either on the bitx but works when hooked to the PC. But like I said there is power at the Radunio... I'm totally stumped.

73,
Jamie - KW4XR

开云体育

Does LCD work when on USB power?

Mike

Make sure the the 16-pin connector to the display is positioned correctly
(you can easily shift it one position by mistake)

73 Allard PE1NWL

On Fri, March 2, 2018 14:55, Mvs Sarma wrote:

try replacing dispay

On 2 Mar 2018 19:22, "Jamie Dean - KW4XR" <jdean72985@...> wrote:

I'm hoping someone has a idea on what to do to fix this.

My YL and I built the Bitx40 with the Raduino three nights ago. It was
working fine till today I
unplugged the Radunio to mount it in a case. When I hooked it back up
the
display will not light up and only a few clicks in the speaker. The unit
will still key with no output power. I checked the voltage and it still
has
12.58 volts at the Radunio. I also hooked the Radunio to the PC to check
if
it was dead. It was able to be recognized and the ardunio software was
able
to talk to it.

Any ideas what might have happened? All connections look ok.

Thanks in advance,
Jamie Dean - KW4XR
Morganton, NC USA

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Yes it lights up but no text. Also the power and light under the display comes on. But not when attached to the bitx.

Jamie - KW4XR

When you connect the Raduino to your PC, it will get +5V power supply via the USB cable.

I checked the voltage and it still has 12.58 volts at the Radunio

This voltage goes to the input of the 7805 voltage regulator. What voltage do you see on the regulator output? (should be +5V).

73 Allard PE1NWL

On 20v range I'm getting 0.04 volts

--

Input is 12.58 volts output is 0.04 volts.
Checked multiple times. It seems it might have gone out?

73,
Jamie - KW4XR

Also check that your ground connection to the Raduino is correct.

If your GND to the Raduino is OK, but you're still getting only 0.04V out
of the regulator, then
- either the regulator output is somehow shorted. Inspect the Raduino
board, check for any shorts, check capacitor C3 (1 uF).
- or the regulator is defective (replace it)

--

If the LCD backlight is bright on USB (you got near 5V) then look for an open regulator.
If the regulator was shorted, it would kill the USB port on your computer?? They parallel up on Raduino?
Someone else this week had a bad 7805, hope that is not a trend?

73's
Mike, WA6ISP whose email is OUT this morning!? Verizon.net sold and now AOL handles it.? It figures!
So I am responding up at the Group Message site.

Yes, a shorted 5v rail on the Raduino would prevent the Nano from powering up from the USB port:
? ??
I assume the Nano clones are similar.


Not obvious what's going on there.? Here's more than you want to know:

Power from the USB port at J3 comes in through fuse F1 to node VUSB and then through schottky diode D1 to drive the 5v rail.
That 5v rail goes to J2 pin 4, which is the same as U1 pin 12 of the Raduino schematic, which is tied to the output of the LM7805 regulator.

So if the LM7805 is working, it powers the Nano through J2 pin 4,? and diode D1 prevents that power from going back up into the USB port.

If the USB port is powered, power can go through D1 to the Nano's 5v rail.
The FT232RL USB interface chip on the Nano (clones use the cheaper CH340 chip) includes a 5v to 3.3v linear regulator to power internal logic,
that 3.3v is available from IC1 pin 17 to power other stuff.? On the Nano, that 3.3v node only goes to J2 pin 14, which is U1 pin 2
on the Raduino, and powers the Si5351 chip on the Raduino.? So no need to include a 3.3v regulator on the Raduino.

If the 5v rail on the Raduino is shorted to ground, then the output of D1 on the Nano is shorted to ground and no logic
on the Nano gets any 5v for power.? However much current the USB host cares to feed us is pouring through F1 and D1 to ground,
this might fry F1 and/or D1, though probably nothing else.

Incidentally, if the Raduino is hooked up to an unpowered Bitx while USB power is supplied,
that 5v can go backwards through the LM7805 and power the Bitx (maybe enough to make the receiver sort of work) from the USB port.
I'd recommend a 1n4007 (or any 1n400* diode) between the Bitx's 12v rail and the LM7805 to prevent this, though have heard of no ill effects yet.
In addition to that 1n4007, perhaps add a 25 ohm 1/2 watt resistor in series to further drop that 12v so the LM7805 doesn't get so hot.
And add caps where the 12v leaves the Bitx and where it enters the Raduino to avoid tuning clicks from the LCD from getting into the receiver.
?
Jerry, KE7ER