I am sure you still have soldering problem somewhere in your board.
Once I experienced the TUNE LED flushing when
I wrongly soldered an external EEPROM to the KT0936.

73

JL1KRA/AA3ZT Junichi

Have you used flux while soldering? Some flux is a bit conductive. Please clean especially in the oscillator area.

Thanks,

Adam

在 2024年3月26日，16:12，haim.jamer@... 写道：

?Just to update, this morning the kit oscillates again even with the regulated power supply at 3.3V

Thanks for the test. More electrolytic caps will make the power on slower and it is more problematic. Power on reset problem could also relate to a slow oscillator. Check if you have installed both 24pF in the oscillator circuit. The crystal could be damaged somehow during the shipping.

Thanks,

Adam

On 2024/3/25 22:15, haim.jamer@... wrote:

That has already been tested and was only 0.04 Ohms.

Those switches are not very reliable and may be erratic. I added an electrolytic? cap across the battery connections at the board but that did not solve the problem.

I think that the issue?is indeed related to the power on reset, since when I shorted accidentally the power connections on the board, the flashing stopped and the radio resumed working.

??

On Mon, Mar 25, 2024 at 3:49?PM Adam Rong <rongxh@...> wrote:

The problem might be related to the power on switch of the battery holder. You can test the resistance when it is switched on. It should be less than 0.1 ohm and it should be stable.

Thanks,

Adam

在 2024年3月25日，21:41，haim.jamer@... 写道：

?

Right now I am testing it with my regulated benchtop power supply and it works properly. However, since the problem is intermittent, I will have to test it for some time.

I will report later on on my findings.

Thanks for your?help.

On Mon, Mar 25, 2024 at 2:45?PM Adam Rong <rongxh@...> wrote:

Hi Haim,

There is a MCU inside the chip. 14 mA current indicates that the receiver portion is not working, but MCU is up since the LED is flashing. Can you change the power supply to a regulated DC power supply of 3.0-3.3V? I suspect the power on reset is not working properly.

Thanks,

Adam

On 2024/3/25 18:12, haim.jamer@... wrote:

It is supplied by 2 fresh alkaline cells. when it flashes it draws approximately 14 mA. When it works properly it draws almost twice that..

On Mon, Mar 25, 2024 at 12:07?PM Adam Rong <rongxh@...> wrote:

What is your power supply? What is the total current when it flashes?

Thanks,

Adam

在 2024年3月25日，17:36，haim.jamer@... 写道：

?

The red led is the tuning led. There is no sound when the led flashes.

On Mon, Mar 25, 2024 at 11:17?AM Adam Rong <rongxh@...> wrote:

Red = Tuning LED?

When it flashes, can you still hear noise?

Thanks,

Adam

在 2024年3月25日，17:03，haim.jamer@... 写道：

?Hello,?
I assembled the kit I purchased and it works sometimes and sometimes the red led flashes on and off at approximately 0.5 of a second.
I checked all connections and solder points but found no culprit.
Has anyone encountered such issue?
Any suggestions?

--

?????

???? ???

--

?????

???? ???

--

?????

???? ???

--

?????

???? ???

The problem might be related to the power on switch of the battery holder. You can test the resistance when it is switched on. It should be less than 0.1 ohm and it should be stable.

Thanks,

Adam

在 2024年3月25日，21:41，haim.jamer@... 写道：

?

Right now I am testing it with my regulated benchtop power supply and it works properly. However, since the problem is intermittent, I will have to test it for some time.

I will report later on on my findings.

Thanks for your?help.

On Mon, Mar 25, 2024 at 2:45?PM Adam Rong <rongxh@...> wrote:

Hi Haim,

There is a MCU inside the chip. 14 mA current indicates that the receiver portion is not working, but MCU is up since the LED is flashing. Can you change the power supply to a regulated DC power supply of 3.0-3.3V? I suspect the power on reset is not working properly.

Thanks,

Adam

On 2024/3/25 18:12, haim.jamer@... wrote:

It is supplied by 2 fresh alkaline cells. when it flashes it draws approximately 14 mA. When it works properly it draws almost twice that..

On Mon, Mar 25, 2024 at 12:07?PM Adam Rong <rongxh@...> wrote:

What is your power supply? What is the total current when it flashes?

Thanks,

Adam

在 2024年3月25日，17:36，haim.jamer@... 写道：

?

The red led is the tuning led. There is no sound when the led flashes.

On Mon, Mar 25, 2024 at 11:17?AM Adam Rong <rongxh@...> wrote:

Red = Tuning LED?

When it flashes, can you still hear noise?

Thanks,

Adam

在 2024年3月25日，17:03，haim.jamer@... 写道：

?Hello,?
I assembled the kit I purchased and it works sometimes and sometimes the red led flashes on and off at approximately 0.5 of a second.
I checked all connections and solder points but found no culprit.
Has anyone encountered such issue?
Any suggestions?

--

?????

???? ???

--

?????

???? ???

--

?????

???? ???

Hi Haim,

There is a MCU inside the chip. 14 mA current indicates that the receiver portion is not working, but MCU is up since the LED is flashing. Can you change the power supply to a regulated DC power supply of 3.0-3.3V? I suspect the power on reset is not working properly.

Thanks,

Adam

On 2024/3/25 18:12, haim.jamer@... wrote:

It is supplied by 2 fresh alkaline cells. when it flashes it draws approximately 14 mA. When it works properly it draws almost twice that..

On Mon, Mar 25, 2024 at 12:07?PM Adam Rong <rongxh@...> wrote:

What is your power supply? What is the total current when it flashes?

Thanks,

Adam

在 2024年3月25日，17:36，haim.jamer@... 写道：

?

The red led is the tuning led. There is no sound when the led flashes.

On Mon, Mar 25, 2024 at 11:17?AM Adam Rong <rongxh@...> wrote:

Red = Tuning LED?

When it flashes, can you still hear noise?

Thanks,

Adam

在 2024年3月25日，17:03，haim.jamer@... 写道：

?Hello,?
I assembled the kit I purchased and it works sometimes and sometimes the red led flashes on and off at approximately 0.5 of a second.
I checked all connections and solder points but found no culprit.
Has anyone encountered such issue?
Any suggestions?

--

?????

???? ???

--

?????

???? ???

What is your power supply? What is the total current when it flashes?

Thanks,

Adam

在 2024年3月25日，17:36，haim.jamer@... 写道：

?

The red led is the tuning led. There is no sound when the led flashes.

On Mon, Mar 25, 2024 at 11:17?AM Adam Rong <rongxh@...> wrote:

Red = Tuning LED?

When it flashes, can you still hear noise?

Thanks,

Adam

在 2024年3月25日，17:03，haim.jamer@... 写道：

?Hello,?
I assembled the kit I purchased and it works sometimes and sometimes the red led flashes on and off at approximately 0.5 of a second.
I checked all connections and solder points but found no culprit.
Has anyone encountered such issue?
Any suggestions?

--

?????

???? ???

Red = Tuning LED?

When it flashes, can you still hear noise?

Thanks,

Adam

在 2024年3月25日，17:03，haim.jamer@... 写道：

?Hello,?
I assembled the kit I purchased and it works sometimes and sometimes the red led flashes on and off at approximately 0.5 of a second.
I checked all connections and solder points but found no culprit.
Has anyone encountered such issue?
Any suggestions?