USB ok but battery plug not working!

[W3SI]

Long story BUT here is short version. I bought my (tr)uSDX KIT from QRPHAMRADIOKITS.COM and built it carefully. It worked great on 40M, 20M and 15M...I didn't try the other bands yet. I was having a great time using it for several weeks on CW, but I wanted better efficiency... so I watched a few videos from Manuel and read a bunch of forum posts and figured that I could handle this task. I began by adjusting RF Board using NanoVNA (20M) and when I assembled 14 pin header...I did not notice that I was one pin off location. Upon applying 12v POP, C8 blew into pcs and smoke was in the air. I said a few magic words about how smart I was, ordered the replacement part and supplies (along with a replacement radio KIT) and I waited and read this forum more! I replaced C8 and carefully applied power, nothing "on display". I figured that my radio was dead!

After chatting with Manuel, I decided to try to troubleshoot the radio. Tonight I used DVM and checked many points for voltages, not knowing what I was really doing. After a while I quit and was reviewing my data compared to Schematic and did not really make any headway. I did note that the USB (5V) connector used a different route thru radio than the 12v plug. So I tried the USB connector and voila!!! Power to Display!

Now before I brick this radio, which would not make me a happy person AGAIN..... does anyone have voltage readings 'test points' that would help me continue to trouble shoot the main board ?

Thanks Manuel for such a great product, it is not idiot proof. LOL Thank you for your encouragement to look at Vcc for troubles, even though I know not what the results should be, I do have some readings. and finally thanks to all of you for taking time to read this and assisting .

73, Bill W3SI

[DL2MAN]

Hi Bill,

Most likely your 7805 died. If you´re lucky, that´s it.
If you´re not lucky, dying 7805 took some other parts with it.

On USB Power: Does it Receive and Transmit ?

73 Manuel; DL2MAN

[W3SI]

It does not power up today using either method !!!

In testing yesterday I measured 7805 to have 12.83v and 1.83v on each outside leg.
I don't know what the 'normal' reading should be on this VR.

I will start troubleshooting again soon. I have a kit from Ali on the way and I will be more careful with 14 pin header alignment.

[AC9YY]

It does not power up today using either method !!!

In testing yesterday I measured 7805 to have 12.83v and 1.83v on each outside leg.
I don't know what the 'normal' reading should be on this VR.

I will start troubleshooting again soon. I have a kit from Ali on the way and I will be more careful with 14 pin header alignment.

With 12.83 volts in it should have very close to 5 volts out, 1.83 is way off. Could be a bad 78L05 or something loading down the 5 volt rail.

[Ohwenzelph]

“ when I assembled 14 pin header...I did not notice that I was one pin off location. Upon applying 12v POP, C8 blew into pcs and smoke “

Than you for the warning, actually I am amazed I have not done that to mine!

[DL2MAN]

“ when I assembled 14 pin header...I did not notice that I was one pin off location. Upon applying 12v POP, C8 blew into pcs and smoke “

Than you for the warning, actually I am amazed I have not done that to mine!

Actually, this cannot happen, when you follow my advise from that Video:
https://youtu.be/qN7hHsvcNMM?t=144
and always use at least lower housing wall before putting power in... Because Housing will not fit if you put it together shifted sideways.

@W3SI:
Yes, your 7805 is definately bad. This is the starting point. Remove it, and test with USB Power Supply if something else has gone south...

73 Manuel; DL2MAN

[W3SI]

I had only enough time to triple check the board for visually bad components and to clean it up a bit so that it looked better under magnification. I will pull t the 7805 and source a replacement. If all else fails I still have a new kit coming from Sunny @ AliExpress

[W3SI]

Tonight I was able to get power to the OLED again and the 20M freq lit up, my call sign, Mode, Filter But no button/knob presses made any difference. No output no transmit and could not change bands.

I have yet to order 7805 and since Thursday, Friday, Saturday nights are date nights with the XYL... this weekend is FL QSO PARTY SO I need to be nice to her. LOL

I did triple check voltages on 7805, input 12.83 output is 1.83 ; I will pull the 7805 soon and try again with 5v USB to see what happens.

Where can I find pin out voltages?
Bill - W3SI