Don't see U4 on the schematics

[Jean-Pierre FERLAY]

Hello, I don't see U4 and the Ethernet port on the schematics. Is it on a extra drawing ?

Thank you for help

Jean-Pierre F5LOL

[Marc OLANIE]

Hi Jean Pierre

 

U4 is the KSZ9031RN, Ethernet PHY IC

 

The schematic is in the « Ethernet » sub-hierarchical template when you open the Hermeslite.pro or hermeslite.kicad.pro. You can also directly open the Ethernet.pro file

 

Drop me a line if you have any other kind of trouble with the schematic and/or kicad

 

73’

Marc f6itu

 

 

 

De : 'Jean-Pierre FERLAY' via Hermes-Lite <herme...@googlegroups.com>
Envoyé : mercredi 28 janvier 2026 15:09
À : Hermes-Lite <herme...@googlegroups.com>
Objet : Don't see U4 on the schematics

 

Hello, I don't see U4 and the Ethernet port on the schematics. Is it on a extra drawing ?

Thank you for help

Jean-Pierre F5LOL

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[Jean-Pierre FERLAY]

Hello Marc, 

Thank you very much, I will try to find the right documentation. Could you contact me on my email  please ?

73 JP

[Steve Haynal]

Are you looking at the Hermes-Lite 2 schematic (not Hermes-Lite 1) on this page?

http://hermeslite.com/

73,

Steve

kf7o

[Jean-Pierre FERLAY]

Hi Steve,

No, I was looking on my papers, and I didn't print the Ethernet page ! It is ok for me now.

Have a nice sunday.

73,

Jean-Pierre

F5LOL

[Jean-Pierre FERLAY]

Hi Steve,
My board has a short circuit between 1.2V and 2.5V. It no longer works. Steve suggested removing FB28. The board works again, but I'm wondering. What is the long-term reliability impact of the short circuit, and what functions are disabled after removing FB28? Thank you for help and advice.

73,

Jean-Pierre 

F5LOL

[Steve Haynal]

Hi Jean-Pierre,

Removing FB28 disconnects the Vlvds bank 5 (IO voltage for FPGA pins) from 2.5V. A voltage of 2.5V or 3.3V is required on bank 5 for many of the FPGA pins connected to the DB1 header. See any FPGA pin on the schematic ending with 5. I don't know how your HL2 is now working. I suspect maybe you have some voltage being fed in through on the bank 5 pins. This can still be a problem. Can you report what the voltage is on each pad of the footprint where FB28 was relative to ground?

73,

Steve

kf7o

[Jean-Pierre FERLAY]

Hi Steve,

Thank you for your reply. The voltages measured while HL2 is active are:

Vlvds = 1.13V

DB1 pin 2 = 1.09V; pin3 = 1.07V; pin4 = 10mV; pin5 = 80mV; pin6 = 1.13V; no activity on the scope for previous pins

DB12 pin1 = 6mV; pin2 = 6mV; pin5 = 70mV; pin6 = 80mV; no activity on the scope for previous pins

What do you think ?

73,

Jean-Pierre

F5LOL

[Steve Haynal]

Hi Jean-Pierre,

I am requesting the voltages at both pads where FB28 was removed.

73,

Steve

kf7o

[Jean-Pierre FERLAY]

Hi Steve,

The voltages at FB28 pads when removed  are: 1.134V and 2.505V

73,

Jean-Pierre 

F5LOL

[Jean-Pierre FERLAY]

Hi Steve,

You have now all the information regarding my short issue. I'm still waiting to find out if the board in my HL2 can be repaired or replaced under warranty. Give me a clear answer please.

Br

Jean-Pierre

F5LOL

[Steve Haynal]

Hi Jean-Pierre,

In your initial post about this problem you said your HL2 has been working for 2 months:

https://groups.google.com/g/hermes-lite/c/yQLRp_DhQEw/m/I_YeXZWEAgAJ

There is a clear repair policy linked from the Makerfabs site and on the wiki. The limited warranty offered by Makerfabs is 60 days.

https://github.com/softerhardware/Hermes-Lite2/wiki/Repair

I help filter out if a defect is due to manufacturing (usually exhibits very early) or user misuse. In your case, I can't clearly determine this and since your initial post was at or beyond 60 days, I can't vouch for a warranty exchange. You can contact Makerfabs directly and see if they are flexibile with their warranty.

We can still look at possible repair of your HL2 in thsi group. Your last message is unclear:

The voltages at FB28 pads when removed  are: 1.134V and 2.505V

Which pad had which voltage?

In another thread, you appear to indicate that the short is on the DB1 side of LVDS. So, with FB28 still removed and now power applied to the HL2, what resistance do you measure between DB1 pin7 (Vlvds) and DB9 pin 4 (+1v2)? I measure about 1.4 KOhm.

If you measure near 0 ohms, then this portion of the Vlvds routing comes nearest to +1v2 on the bottom of the PCB shown below near B22 and B29. Please inspect that area carefully for any possible solder bridge or trace short in the PCB.

73,

Steve

kf7o

[Steve Haynal]

There is a typo below. It should be:

with FB28 still removed and *no* power applied to the HL2,

[Jean-Pierre FERLAY]

Hi Steve, thank you for your reply. 

My HL2 was delivered on December 4, 2025, and my first message on the Group is dated January 27, 2026, exactly 55 days after; I am in the warranty period of 60days.

In my last message regarding the voltages at FB28,  I wrote "FB28pads" exactly where FB28 was soldered. Today the resistance between DB1/7 and DB9/4 is exactly 0.0 Ohm.

I checked carefully the PCB according your recommendation and I see no short or solder bridge.  

For my opinion, the board must be repaired or replaced by Makerfabs. Could you help me  contact  them to arrange this replacement please ?

Best regards,

Jean-Pierre

F5LOL

[Steve Haynal]

Hi Jean-Pierre,

Please contact Makerfabs directly. See the warranty information at the bottom of www.makerfabs.com. They have all shipping and order details which will be required. I am not involved with that. Provide them with links to these Google Group threads if you need proof of when the problem first occurred. Makerfabs does want to make customers happy. According to the repair wiki, you should have already contacted makerfabs since your problem occurred more than 45 days after shipment:

https://www.makerfabs.com/warranty-and-return

Again, my role is to make sure no hardware problems are due to use issues or obvious manufacturing errors. I only recommend warranty replacement to Makefabs when I am quite certain there was an obvious original issue with the board. In your case, I can't say for certain. From my experience, problems with shorts between 1.2V and 2.5V appear because the user has incorrectly used IO pins or connections to the HL2, but in your case I don't know what happened.

73,

Steve

kf7o

[Jean-Pierre FERLAY]

Hi Steve,

I understand what you explain, but I didn't use the IO pins of DB1. For your information, I remember my HL2 freezing at a point where there was a simultaneous PTT operation between the microHAM CW Keyer connected to CN4 and the PTT performed by N1MM via the CAT link. I use Thetis. I don't use the PA, only the low power output and a 47dB gain linear amplifier. I tried a reset using the procedure indicated in the manual, which said to be patient, but the HL2 remained unresponsive. I hope Makerfabs will understand my problem. 

73,

Jean-Pierre

F5LOL