HL2 unable to power up (+1V2 and GND = 86.5 ohms)

[Philip Lai]

Hi Steve, All,

Greetings, I assist in HL2 FB group moderation and was in touch with Kenneth Brandon (His email available) who is unable to join this IO.

He has done some detailed checks based on schematics (all good) except when we suggested to check power supply short.

Result of PS short check:

All points produced 0 value except (+1V2 and ground) shows 86.5 ohms.

As his unit is >60 days (1yr odd), who can he send to for repairs/further checks?

73,

Phil 9V1PL

[Steve Haynal]

Hi Phil,

First posts to this group must be approved, but I don't remember seeing any posts from Kenneth Brandon.

If he sees 0 resistance for most power supplies to ground and only 86.5 Ohms for +1V2 then it sound like something major has gone wrong. Ask him to:

1. Remove the HL2 from the enclosure
2. Only apply power to the HL2 (disconnect any N2ADR or IO board)
3. Measure voltages at the test points seen here https://github.com/softerhardware/Hermes-Lite2/wiki/Hardware
4. Report the measured voltages
5. While doing this, use fingers to see if any components are getting very hot. Remove power if something is getting very hot and report what becomes hot.

There is no support beyond the initial 60 day limited warranty except for some limited help on this official Hermes-Lite group. Sometimes you might find a volunteer willing to attempt a repair. At the HL2 price point, people should not expect full service repair or support. The HL2 is primarily a unit for DIY and homebrew types who are comfortable with making their own repairs or the risks with purchasing such a product. Interest has exploded in the HL2, partly due to the FB group, and I worry many new HL2 users don't understand this.

73,

Steve

kf7o

 

[Philip Lai]

Hi Steve,

Yes sometimes my response offended some when we comment this is not a PnP radio off the rack lol!

Here are the readings Kenneth got from his unit.

Anything glaring here?

·  +3V3 and GND =3.30v

·  +2V5 and GND =2.50v

·  +1V2 and GND =1.2v

·  Vbias and GND =0.0v

·  Vsupply and GND =13.88

·  Vop and GND = 0.0v

·  Vpa and GND =0.0v

·  +3V3 and +2V5 =.79v

·  +3V3 and +1V2 =2.0v

·  +2V5 and +1V2 =1.3v

Thank you once again for looking into this for Kenneth.

73,

Phil 9V1PL

[kbcanbe]

Gentlemen,

Thank you very much for the troubleshooting assistance. The tested values as requested and per instructions are as follows.

• +3V3 and GND =3.30v
• +2V5 and GND =2.50v
• +1V2 and GND =1.2v
• Vbias and GND =0.0v
• Vsupply and GND =13.88
• Vop and GND = 0.0v
• Vpa and GND =0.0v

• +3V3 and +2V5 =0.0v

• +3V3 and +1V2 =2.0v
• +2V5 and +1V2 =1.3v

Any Feedback is greatly appreciated

Kind Regards

Ken

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[Steve Haynal]

Hi Ken,

Thanks for the measurements. All measurements relative to ground look correct. The measurements from one power supply to another are not really needed as ground is common for all power supplies.

Did anything get hot? Do you have a current limiting power supply which shows the current draw? What is the current draw?

With the HL2 removed from the enclosure and no ethernet cable or antenna connected (no other boards too), just power, what is the state of all 4 LEDs immediately after powering on and after 2-3 minutes?

Please post high resolution photos of the top and bottom of your HL2. Modern phone cameras take decent photos.

73,

Steve Haynal

[Philip Lai]

On behalf of Kenneth Brandon:

Steve,

I have no real way to measure current draw. Nothing getting hot on the board. I left Hermes plugged up to the power supply for 5 min with no lights lighting up. I have attached IMages of both the Top and BOttom of the Board as requested. Again, thank you very much for your assistance.

Kind Regards

Ken Brandon

[Philip Lai]

[Philip Lai]

[Steve Haynal]

Hi Phil,

Kenneth is able to post to this group as seen in this post:

https://groups.google.com/g/hermes-lite/c/tqb6980MLgU/m/ob2qSBKpBwAJ

Why isn't he posting this information directly?

73,

Steve

kf7o

[Philip Lai]

Hi Steve,

I thought so too.

Not sure why he contacted you directly too.

Will advise him to just reply all in his email. It will be posted that way too.

73,

Phil 9V1PL

Sent from my iPhone

On 11 Jul 2025, at 12:44 PM, Steve Haynal <softerh...@gmail.com> wrote:



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[Steve Haynal]

Hi Kenneth,

I don't see anything alarming in the photos.

Since no LEDs light or blink, this points to a problem with the FPGA. There are two clocks connected to the FPGA. One for the ethernet and the other for the ADC. One clock causes the left most LED to blink. The other clock causes the right most LED to light solid. It is unlikely that both clocks are not functioning and more likely that there is a problem with your FPGA. A good indication that the FPGA is running the correct gateware is HL2 current consumption which should be ~160mA with no ethernet or N2ADR board. This is a basic measurement and since you said you have no way of doing this, I don't have much hope for more debug or repair. Beyond the current measurement, the next steps I would recommend are:

1. Force a factory image boot. Maybe your FPGA image is corrupted. https://github.com/softerhardware/Hermes-Lite2/wiki/Updating-Gateware#force-factory-image-boot

2. Check if the FPGA is alive using a USB blaster. https://github.com/softerhardware/Hermes-Lite2/wiki/Updating-Gateware#usb-blaster-clone

Further debug and repair will likely require an oscilloscope and surface mount component replacement skills.

[Tim Thorson]

I've only cursually been following this thread and do believe there was confirmation of correct voltages on board..(?)

It looks as if to me, a soldering iron accidentally rested on the Jack body (damaged?) lower right hand corner of the photo...

Tim KD6HOF

On Thu, Jul 10, 2025 at 9:35 PM Philip Lai <phil...@gmail.com> wrote:

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[Philip Lai]

I noticed that as well, Tim.

Kenneth informed that his HL2 wouldn’t power up after he came back from out of town. He also informed that everything was unplugged during his absence except for UTP cable to RJ45 port.

Sent from my iPhone

On 12 Jul 2025, at 1:32 AM, Tim Thorson <9165r...@gmail.com> wrote: