No Power out

[Fabio Bertolotti]

hello all, i have a problem with my HL2.

immediately the adc lights didn't turn on even with the gain set to maximum, still receive "normally"... in transmission instead I had no power, pressing U7 and other parts of the PCB I saw power on the instrument, about 3watt in 10mt.

so I tried to redo the soldering on U7 and other integrated .... moral, the ADC LEDs turn on and off according to the gain adjustment, while as regards the output power nothing to do, now even by pressing the PCB nothing changes...

do you have any idea about it? the pins of U7 have no short circuits, I was wondering if the lower pad of the same chip was soldered on the pcb or not, obviously I didn't unsolder everything, I just re-soldered the pins...

thanks everyone for the help.

IZ4DPW

[Steve Haynal]

Hi IZ4DPW,

When did you purchase your HL2 and when was the ship date from Makerfabs?

Is it a correct understanding that receive works but transmit no longer produces any power? Did transmit work in the past, then became intermittent, and now stopped?

1. Please report if there is any transmit power into a dummy load for either the ANT or RF1 connectors when running Quisk or SparkSDR and pressing a CW straight key connected to the front panel. Ground tip to shield of the CW connector.

1a. Also, if you have an oscilloscope, please measure and report any signal seen on DB3 pins 3 and 4 while trying the above CW key experiment.

2. Since you reworked the AD9866, please send a high resolution photo (phone photo is okay) of the AD9866.

3. Please solder the hole on the bottom of the PCB underneath the AD9866. It can take some time for an iron to heat this pad up.

73,

Steve

kf7o

[Fabio Bertolotti]

hello and thank you very much for the reply.

the hl2 exactly I don't know when it was bought, I bought it used and for a while it worked correctly both in rx and tx.

then for a period it was used only in rx and when I resumed transmitting after a while it gave that defect that I described before.

I have already tried to transmit in cw directly from the external key, but no output power (with a receiver you can hear the cw note and also the modulation but without signal).

I have an oscilloscope, I will try to make the measurement.

on dummy load 0watt...

can you confirm that the base of the ad9688 wants to be welded? I only redid the soldering of the "external" pins. looking at the pcb from the opposite side through the hole, you can't see tin and I wonder if it's not tin-plated.

however I do the tests and the photos you suggested. I can take pictures with a microscope.

thanks a lot for the support

Fabio

IZ4DPW

[Steve Haynal]

Hi Fabio,

Yes, I recommend soldering the base of the ad9866 through the hole. The thermal pad is soldered by Makerfabs, but sometimes I think that hole actually causes problems. 

If it still doesn't work, I think you need to replace the ad9866. You can order one from Mouser or DigiKey and replace it yourself or hire a local phone repair company to replace it. If you want to gamble a little, you can find the ad9866 on aliexpress.com for under $20 but beware. The quality can vary widely. I have bought some ad9866 from aliexpress which are still working. I have also bought some which a professional assembly house told me had microscopic cracks and water damage. From my small sample set (under 20), maybe ~66% will work?

73,

Steve

kf7o

[Fabio Bertolotti]

Ciao,

Pictures of AD9866

[Fabio Bertolotti]

Il giorno mercoledì 19 luglio 2023 alle 22:36:31 UTC+2 Fabio Bertolotti ha scritto:

Ciao,

Pictures of AD9866

[Fabio Bertolotti]

[Fabio Bertolotti]

[Fabio Bertolotti]

[Steve Haynal]

Hi Fabio,

Thanks for the pictures. I didn't see any problems, but it is a little hard to tell given the angle of the pictures. You can see more if the angle is more from the side.

Please see my last post. If resoldering the thermal pad of the ad9866 does not help, then I think you will have to replace the ad9866.

73,

Steve

kf7o