---
title: "LED is not working for RB1-125BAG1A"
url: "https://maker.wiznet.io/forum/12913"
markdown_url: "https://maker.wiznet.io/forum/12913/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "ekazyam"
created: "2018-05-24T00:28:52+09:00"
last_activity: "2018-06-20T04:32:40+09:00"
language: "en"
views: 1216
replies: 3
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# LED is not working for RB1-125BAG1A

## Question

Asked by ekazyam on 2018-05-24 in Ethernet Chips.

Hello all,

I used the RB1-125BAG1A in my product , but it have the problem.
The green LED is not working, but the L3/L4 direction change , it work.
The datasheet is wrong ?

[datasheet in digikey](http://www.shopwiznet.com/lanotattachments/download/file/id/95/store/1/)

[![myproduct_pcb](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/c/cb91d2224d72d38a5afda677e885c52160e8105c.jpeg) myproduct_pcb1704×680 181 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/c/cb91d2224d72d38a5afda677e885c52160e8105c.jpeg)

## Replies

### Reply 1 by ekazyam, 2018-05-28

I bouth the it from other shop.

I checked the different point.
1720-> it’s not working and different the datasheet.
1730aa-> it’s working and same the datasheet.

[![Image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/6/69bfadc8e55fa2a3fb3b11c3b8ef849b82ca34d4.jpeg) Image330×570 61 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/6/69bfadc8e55fa2a3fb3b11c3b8ef849b82ca34d4.jpeg)

I think that 1720 is old model , and it changed the pinout.

### Reply 2 by Eugeny, 2018-06-19 (in reply to reply 1)

1730 and 1726 must be manufacture timestamp, both devices must relate to the same datasheet. It may happen that 1720 batch is just failty. Did you try measuring voltrop on the related pins using multimeter in both direction to see if it has any diode behavior?

### Reply 3 by ekazyam, 2018-06-20

Yes, I checked leds both directions, but it’s not working.(1720 lot numbered parts)
and I tryed reverse directions(this is not same the datasheet).
it’s working true.

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Source: https://maker.wiznet.io/forum/12913