Remi,
Will do when I get some time. Meanwhile, the Nano is inverted, the USB connector on the display side. The headers pins on the Nano are on the USB connector side of the board. That maintains the previous orientation while moving it to the other side of the board. -Don

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

No, looks like TX to one of the many ground connections on the kit board. Quite solid, thus the smoked trace. There is something else going on, too. Probably minor. -Don

Possible, I don't really know what would happen if both sides of a bidi amp were turned on.
But his burnt trace probably saw amps, and not obvious to me how the bidi amps could pull that kind of current.
DC paths from TX to ground are hundreds of ohms, AC out has a series 50 ohm resistor.

Remi, this is the new V4 board and I am pleased to report that the Nano is now socketed . Without removing anything soldered, with the display still not connected, I measure 1,590 ohms from the +5 output of the 7805 to ground reference (the 7805 tab). Both polarities, indicating that my ohmmeter has low enough applied voltage not to cause any junctions to conduct. Did you measure to see if the +5 volts was actually what was expected? -Don

Oh, one more thing Jerry, The mods I had done was the cutting of the traces per the instructions on Don ND6T's site. I bridged them back to factory and checked with a MM to make sure the path was back. There is no visible damage to the top side of the PCB as looked at with my USB Microscope, (a good one).

Joel
N6ALT

Don, Jerry, thank you for trials and excanges,
unpluging the display (after power off Of course) i got still 210mA?
don i assume you have ashan genuine firmware, do you have v3 or v4 board (i’ve not seen difference on Raduino board)
3 more power consomption than your’s i might have a problem or a very bad nano board
I’l Check voltage after diner, and Also put the firmware inside another ?nano board i have (not easy to Check the nano board on ?the raduino because There us a lot Of solders to remove)

Thanks for all the great replies, I'm really embarrassed to admit I did this. Jerry, you are right about what caused this. It didn't work at all when I tried it the first time, after looking at everything I thought I had the wire going to C50 on the click board on the wrong pad, so I swapped them, (big mistake), now at least I had bad receive, then I pushed the PTT, that's when the magic smoke got let out. I checked the raduino outputs with my frequency counter and the outputs were all what they should be for the frequency I was on.

C50 and C63 are replaced with new caps and are fine. I will check the other things you mentioned as well. Thanks for the offers to buy my board, but that doesn't really help me with my problem. I will try to repair before I think about selling it. Thanks again for all your help. I will post on this thread and let you all know how things turn out. Picture of top side of PCB below.

Joel
N6ALT

I repeated the test using my highly accurate Harbor Freight meter.? ;-)
Not the needle on my old linear power supply.
My figures now agree with Don's measurements to within a couple ma.
?
Voltage should not affect the current draw by much at all.
Should be the same current with 8v as it is at 15v into the Raduino, within a couple ma.

Joel,
Since it did not go poof until you activated the PTT, then it might have been an incomplete cut of the TX trace. With both TX and RX voltages active then both sets of IF amps will be active (truly bidirectional) and will likely form a full-on oscillation! Check Q12, Q21, Q32, and Q40 as a start. Like Mike says, look for discoloration. Sniff the areas. -Don

On Sat, Jun 23, 2018 at 11:09 am, Don, ND6T wrote:

OK, I just did the same test. Brand new, just out of the box, 12.5 volt source. I get 61.5 milliamps. De-power. Unplug the display. I get 40.8 milliamps when repowered. -Don

No worries, Joel! Although I am sorry that it happened. The trace appears at first glance to be the TX trace. If it were cut in the wrong place and jumpered to the +12 volt bus then you were probably transmitting. Look at the PA finals. Best to check resistances in several places in the TX areas. No, it can be repaired. Just a bit of an adventure.
I advocate using a current limited supply to avoid that. I dial the maximum current down to just over what I would expect to be normal before applying power. In this case a 0.2 amp current fold-back would be appropriate. By observing the voltage with your finger on the switch you can usually avoid most unpleasantries. Drop me a line on my regular email if you want. 73,
Don

Easy enough to foul up like that, I've done worse.
More than once.

Well worth an hour or two of trying to chase this down.
I'd expect it to be repairable.

The trace you burned is the TX +12v rail.
My best guess is it somehow got wired up to ground during your mods.
Look hard for other burn spots where the TX rail might have been damaged.
And look hard at wherever it had been shorted, may be some damage there too.

Verify that your RX rail is 12v during receive and TX is 12v during transmit.
Sounds like that is probably the case.

Exactly what list of mods were you trying to follow?
Exactly what was the mis-wire?

Where do you hear 60hz hum when probing around the audio during RX?
Do you get noise when touching T7 pins 3 and 5?

Did you restore C50 and C63?
Perhaps C63 got cracked when working with it, perhaps receive audio is?
not making it through C63.? Perhaps try replacing C63 with some other cap of 0.1 to 1 uF.
Maybe the traces got ripped up a bit around C63 when it was removed?

You can continue? touching stuff back through the receiver all the way to the antenna,
should hear increasing noise as you continue further back.?
Just touch it with 3 feet or so of wire connected to nothing, that's enough of an antenna
to pick up household QRM and inject it into the circuitry.
The further back you go, the more amplification it gets before arriving at your speaker.
When you get to a spot where touching stuff no longer makes an audible difference,
you have gone past the fault in the receiver.

If there's loss of noise at or immediately beyond a mixer (other side of the filter that's in front of the mixer)
then check the si5351 clock going into the mixer.? You can check the si5351 clocks by monitoring them in some
other shortwave receiver.? ?With stock firmware, Clk0 is around 11.9965 mhz, Clk1 is at 32.995mhz (LSB) or 56.995 (USB),
and Clk2 is at the 44.995mhz+OperatingFreq.? So if you are tuned to 7mhz, then clk2 should be within a few khz of 44.995+7=51.995mhz

Jerry, KE7ER

开云体育

I forgot to mention that the board smoked when I pushed the PTT, it was working sort of until I did that.

Joel
N6ALT

Remi,

OK, I just did the same test. Brand new, just out of the box, 12.5 volt source. I get 61.5 milliamps. De-power. Unplug the display. I get 40.8 milliamps when repowered. -Don

Unplug the display.
Then how much does the main Raduino board draw?
I measured mine (crudely though, at the bottom end of my power supply's ammeter) at 60ma.

Verify that the voltage out of the LM7805 is 5 volts.

Is something other than the LM7805 also getting hot?

I debated on whether I would admit to being this stupid to the group, but while fitting the click fix board to my perfectly working uBitx all mounted in a custom enclosure, I vaporized a trace on the bottom of my board. Obviously I did something wrong, although I don't know what. I reversed the mods to the PCB and replaced the vaporized trace with a piece of wire and fired it up. I have no RX or TX however the Raduino is working and outputting the correct clock signals on the three pins. It does switch to TX when pressing the PTT, and believe it or not, the whole audio section seems to work fine. I can touch parts in the audio section and hear a loud 60 cycle hum out of the speaker. I can hear a slight hiss in the speaker that does not change when removing the antenna. So this brings me to the part where I ask if it would be worth trying to trouble shoot this board, (any idea where to start?) or just replace it. Does anybody have just a Ubitx PCB they would sell me (cheap) as my raduino works fine. This radio worked good, I should have left it alone:-( Picture of burnt trace below.

Joel
N6ALT

tnx don, larry, jerry
My raduino alone (now, it was more yesterday) consume 230mA on a 12V battery