Check the PTH as I mentioned..

Joel,

If the TX track is burnt there it is likely that a plated through hole (PTH) has also burnt.
Check along the burnt line from top to bottom connections.

Check the RX/TX supply voltages everywhere.. you could have welded the relay contacts !!

Raj

The receiver would not work until I changed the relay. I was wondering about that myself, why would the absence of TX voltage cause the receiver not to work unless a RX voltage was missing also. I checked all that I saw on the schematic and they were all there. Don’t know.

Joel
N6ALT

Cool!
It does pay to just dive in and try.? Sometimes.

I am curious though, what was wrong with the receiver?
Perhaps trouble around C50?

Jerry

Sounds like a defective Nano.? But could still be a shorted Nano IO pin.?
Might check all of those IO pins with an ohmmeter to ground, +3.3v, and +5.5v with power off,
and look again (I know you already did) for a possible short somewhere.

Maybe a bit of solder or a metal filing fell into the works?
Wash it all with alcohol (which dries fast), see if that helps?

But I think you are on the right track.
The Nano is only $3, but difficult to remove.
If you do wind up removing it, consider installing a socket when putting the new Nano in place.
This worked well:??/g/BITX20/message/49986

Here's a datasheet for the CH340:??
And a schematic for the Nano:??

Jerry, KE7ER

7805 Input is direct battery=12.55V (if it’s going ?hot, IT me and IT HAS power to dissipate due to current x deltaV)
0,23A is a problem when :
- it’s going to heat too ?Much ?the 7805
- at least 2 om measured the third on their board
- it’s going to sink battery?
- the processor is also heating too much
73

开云体育

Remi,

What do you read on the input pin of the 7805?

Still sounds "fishy"? ??? 7805 does .23A OK?? Should be no problems if not hot?

Yes climbing temp is a problem?

Mike

Mike (and others), the 7805 output is (only) 4.79V, with input at 12.55V (see picture) (Pb battery), I assume the low voltage is due to high current/power drain (0.23A = not far 2W), I don't think the low voltage could be the origin of the high consumption (the Atmega328 is given for 1.8-5.5V, downgrading clock with low voltage, but 4.79V is normal to +-5%)
I've also found Atmega328 temp is climbing very Hot (not as the 7805 but too hot for this kind of circuit), that might be the original problem, is it a defective nano board ? (despite this it start to work fine)
73 - Remi

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

Mike (and others), the 7805 output is (only) 4.79V, with input at 12.55V (see picture) (Pb battery), I assume the low voltage is due to high current/power drain (0.23A = not far 2W), I don't think the low voltage could be the origin of the high consumption (the Atmega328 is given for 1.8-5.5V, downgrading clock with low voltage, but 4.79V is normal to +-5%)
I've also found Atmega328 temp is climbing very Hot (not as the 7805 but too hot for this kind of circuit), that might be the original problem, is it a defective nano board ? (despite this it start to work fine)
73 - Remi

开云体育

You must have low voltage into the 7805 or it is bad.? That seems to low?

Sounds like it is dropping out because of low input voltage.? Should be about a minimum of 8V input, depending on the part?

I have made a lot (>50) of my "Better Raduinos", the 5 volts is good to +/- .05V or so?? I use a 47 Ohm 1W resistor in front of the regulator.? I would not go over 47 Ohms.

Mike, WA6ISP

Don,
Ohmmeter is not signifiant (which seems normal): 165K on 2M, 20K on 200Kohms, 2.59K on 20K, 640ohms on 2K,
The 7805 output is 4.79V
Don could you send me a pic to see how the nano socket is mounted to allow the display board to be put onto it ? perhaps longer display connector
-remi

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

Jerry (and others), my finger says that nano's processor is also heating (that sound that the problem is on the nano or raduino board)
I looked at the board, no extra coper or solder which could make short circuit
73
Remi

I also found 3.5V on the 3V3 output of the Nano (that's in the range for FT232 or PL2303 : 3-3.6V, high but in the range -no datasheet for CH340)

Hi all,

?I want to thank you all who held my hand through this, I am now back up and running. The low power was because I had my power supply in current limiting mode, I now have full power out and worked a field day station a 1000 miles away. I will install a fuse in the primary radio path now that I've learned a important lesson. Some people just need to learn the hard way:-)

Joel
N6ALT

sorry, no.

Vince.

--
Michigan VHF Corp.

Thanks Vince, that's often on nano clones, do you have any current consumption data on your side ? (with details (genuine firmware, v3 or v4)
73 - Remi

Yay! K1 was indeed bad, I now have a working receiver and transmitter, however the output power is only 500mw compared to the 12 watts before. Do we think the IRF510's are shot? What would be the best way to check them or should I just replace them, I have plenty in stock.

Joel
N6ALT

Thanks Vince, mine is totally unlabeled on the top. Unusual.
Thanks Remi. Please keep us posted.
73,
Don

It's the CH340.

Vince - K8ZW.

--
Michigan VHF Corp.

Thanks Don your description is fine, i understand what have been made
do you know what serial board is under the nano ? (FT232, PL2303, CH340 ?) (with the new mount it's probably more easy to see than on solders'one)
(for what i've seen it might be FT232, but nano boards exists with thes 3 chips, if i plan to exchange nano board, i 'll try the same)
73 - Remi

It seems to be a problem with my raduino board (or nano but as it's soldered, its hard to test further), i'm going to ask for warranty to get raduino replacment, does someone know how i can ask that ? (teamhfsigs@..., paypal, ...)
73 - Remi - F1MQJ