---
title: "custom W5500 + RJ45 (HR911105A) – Link/ACT LEDs not lighting up"
url: "https://maker.wiznet.io/forum/15758"
markdown_url: "https://maker.wiznet.io/forum/15758/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "aravi_iot"
created: "2025-06-12T15:54:53+09:00"
last_activity: "2025-06-13T17:49:57+09:00"
language: "en"
tags: ["MicroPython", "ESP32", "W5500"]
views: 7
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# custom W5500 + RJ45 (HR911105A) – Link/ACT LEDs not lighting up

## Question

Asked by aravi_iot on 2025-06-12 in Ethernet Chips.

I'm using an ESP32-S3 with MicroPython and a custom W5500 Ethernet module connected via SPI. I can successfully communicate with the W5500 — reading the version register returns 0x04, so SPI works fine.

But... when I plug in an Ethernet cable (connected to a router or PC), the RJ45 Link and Activity LEDs do not turn on at all.

**My Setup:**

- W5500 connected via SPI to ESP32-S3

- 25 MHz crystal working correctly

- RJ45 connector: HR911105A (magnetics integrated, with LEDs)

- 3.3V supply to W5500

- I am designed the schematic using wiznet reference schematic

- LINKLED (pin 25)

- ACTLED (pin 26)

LED Wiring (Current Plan):

| **RJ45 Pin** | **Description** | **Connected To** |
| --- | --- | --- |
| 9 | GRN+ (Link LED anode) | +3.3V |
| 10 | GRN− (Link LED cathode) | W5500 pin 25 (LINKLED) via 330Ω |
| 12 | YLW+ (ACT LED anode) | +3.3V |
| 11 | YLW− (ACT LED cathode) | W5500 pin 26 (ACTLED) via 330Ω |

Is this the correct configuration?

❓ Questions:

- Any differential errors in this PCB design

- what is the reason of link/ACT LEDs not lighting up when ethernet cable is connecting?

- Can you reverify the schematic diagram

Any help or examples from people who got W5500 working with ESP32 would be greatly appreciated.

Attachments:

- [w5500_sch_v110_use_mag_-19e2939c3f018e5d72f1b957f990f96d (1).png](https://maker.wiznet.io/forum/getAttach.asp?aidx=242)
- [Screenshot 2025-06-11 200441.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=243)
- [Screenshot 2025-06-11 200502.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=244)
- [Screenshot 2025-06-11 200545.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=245)
- [Screenshot 2025-06-11 201043.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=246)
- [Screenshot 2025-06-12 110928.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=247)
- [Screenshot 2025-06-13 114414.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=249)
- [Screenshot 2025-06-13 114428.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=250)

## Replies

### Reply 1 by Alan, 2025-06-13

Hello, How are 3.3VD and 3.3VA connected?

### Reply 2 by aravi_iot, 2025-06-13 (in reply to reply 1)

3.3VD (digital) and 3.3VA (analog) are not directly connected together. Instead, they are connected through a ferrite bead, specifically:

Acts as a high-frequency filter between digital and analog domains.
Any issue with this schematic?

---

Source: https://maker.wiznet.io/forum/15758