---
title: "Custom W5500 design, W5500 chip is detected but the LEDs are not working Link/ACT"
url: "https://maker.wiznet.io/forum/16024"
markdown_url: "https://maker.wiznet.io/forum/16024/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "WahyuStroomer"
created: "2026-03-30T18:55:52+09:00"
last_activity: "2026-03-30T19:00:50+09:00"
language: "en"
tags: ["W5500", "Arduino IDE"]
views: 5
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Custom W5500 design, W5500 chip is detected but the LEDs are not working Link/ACT

## Question

Asked by WahyuStroomer on 2026-03-30 in Ethernet Chips.

I'm using an ESP32 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.

1. W5500 connected via SPI to ESP32 WROOM 32U

2. 25 MHz crystal working correctly

3. RJ45 connector: HR911105A (magnetics integrated, with LEDs)

4. 3.3V supply to W5500

5. I am designed the schematic using wiznet reference schematic

6. LINKLED (pin 25)

7. ACTLED (pin 27)

I have done testing by removing the 33R resistor, but it still doesn''''''''t work.

please help me to review my design, Thankyou

![](https://maker.wiznet.io/upload/ckeditor5/221219568%5F1774897202%2Ejpg)

![](https://maker.wiznet.io/upload/ckeditor5/221219568%5F1774897158%2Epng)

Attachments:

- [W5500 design.png](https://maker.wiznet.io/forum/getAttach.asp?aidx=343)
- [W5500 IO.pdf](https://maker.wiznet.io/forum/getAttach.asp?aidx=344)

---

Source: https://maker.wiznet.io/forum/16024