# Solved: aliexpress 2 string passive adapter not working because Rpi connector was soldered on the wrong side of the board **URL:** \ **Category:** Uncategorized\ **Created:** [October 12, 2024, 10:15pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892 "2024-10-12T22:15:09Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![marcmerlin](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/marcmerlin/32/40_2.png) [@marcmerlin](https://rpi-rgb-led-matrix.discourse.group/u/marcmerlin)\ **Post date:** [November 19, 2024, 10:54pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/21 "2024-11-19T22:54:50Z")
I already did and suggest you do the same. Which seller did you get it from? ---
**Author:** ![marcmerlin](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/marcmerlin/32/40_2.png) [@marcmerlin](https://rpi-rgb-led-matrix.discourse.group/u/marcmerlin)\ **Post date:** [November 19, 2024, 11:15pm UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/22 "2024-11-19T23:15:38Z")
[https://www.aliexpress.us/item/3256806177226619.html](https://www.aliexpress.us/item/3256806177226619.html) is confirmed bad, waiting to hear from seller. [https://www.aliexpress.us/item/3256806254319466.html](https://www.aliexpress.us/item/3256806254319466.html) is in the mail and looks like it will also be bad ☹ They sell an “unwelded” version which would allow me to solder the rPi connector on the correct side, but of course I ordered the pre soldered one, because it’s not like I need more soldering jobs. Of course, now I have an unsoldering/resoldering job which is even worse :-/ Maybe it’s a good time to figure out if I can learn to use my heat gun to unsolder all those pins at once. ---
**Author:** ![Qxji](https://avatars.discourse-cdn.com/v4/letter/q/bbce88/32.png) [@Qxji](https://rpi-rgb-led-matrix.discourse.group/u/Qxji)\ **Post date:** [November 20, 2024, 12:49am UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/23 "2024-11-20T00:49:21Z")
I got mine refunded, they didnt even let me contact the seller. I got 2€ back tho so I guess yay? ---
**Author:** ![Qxji](https://avatars.discourse-cdn.com/v4/letter/q/bbce88/32.png) [@Qxji](https://rpi-rgb-led-matrix.discourse.group/u/Qxji)\ **Post date:** [November 20, 2024, 12:51am UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/24 "2024-11-20T00:51:44Z")
[https://aliexpress.com/item/1005006838274518.html](https://aliexpress.com/item/1005006838274518.html) is the one I got, I hope the link didnt break ---
**Author:** ![Qxji](https://avatars.discourse-cdn.com/v4/letter/q/bbce88/32.png) [@Qxji](https://rpi-rgb-led-matrix.discourse.group/u/Qxji)\ **Post date:** [November 20, 2024, 12:53am UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/25 "2024-11-20T00:53:18Z")
We should probably write some reviews warning folks with both the active passive thing which seems to be less of an issue and the solder issue which seems to affect all of these so thats (un)cool ---
**Author:** ![marcmerlin](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/marcmerlin/32/40_2.png) [@marcmerlin](https://rpi-rgb-led-matrix.discourse.group/u/marcmerlin)\ **Post date:** [November 29, 2024, 12:07am UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/26 "2024-11-29T00:07:54Z")
I replied to all 3 amazon sellers to give 1 star reviews and photos. Please rate your own seller on aliexpress with 1 star review too. In the meantime I received the blank board unsoldered, soldered it myself the correct way and it works fine. With root@DietPi:~# ~/rpi-rgb-led-matrix/examples-api-use/demo --led-slowdown-gpio=4 --led-panel-type=FM6126 --led-rows=64 --led-cols=128 --led-row-addr-type=3 --led-chain=1 --led-parallel=2 --led-show-refresh --led-scan-mode=1 --led-pwm-bits=4 --led-pwm-lsb-nanoseconds=50 -D0 --led-pwm-dither-bits=1 I get 350Hz on 2 ABC panels (128x128 total res) ![PXL_20241128_233330545](https://global.discourse-cdn.com/free1/uploads/rpi_rgb_led_matrix/original/1X/ff8fa11c014a9112cb31d6f0a60b53c70249452d.jpeg) ![PXL_20241128_233625566](https://global.discourse-cdn.com/free1/uploads/rpi_rgb_led_matrix/original/1X/654fafa05ddd79b6e4f945d07e99117ac685f101.jpeg) This shows the correctly soldered board on left, then the incorrect one, the incorrect one I tried to unsolder (oh boy, what a mess), and a blank board with the connectors put in the correct way (not soldered yet) ![PXL_20241128_225531760](https://global.discourse-cdn.com/free1/uploads/rpi_rgb_led_matrix/original/1X/8a584b59a1da068112905d3a37923521a756353e.jpeg) ---
**Author:** ![baicker.009](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/baicker.009/32/464_2.png) [@baicker.009](https://rpi-rgb-led-matrix.discourse.group/u/baicker.009)\ **Post date:** [March 20, 2025, 5:34am UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/28 "2025-03-20T05:34:54Z")
@marcmerlin could you share the link of this P1.87 128x64 pannel ? What type of chipes are? ---
**Author:** ![marcmerlin](https://yyz2.discourse-cdn.com/free1/user_avatar/rpi-rgb-led-matrix.discourse.group/marcmerlin/32/40_2.png) [@marcmerlin](https://rpi-rgb-led-matrix.discourse.group/u/marcmerlin)\ **Post date:** [March 23, 2025, 1:36am UTC](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892/29 "2025-03-23T01:36:41Z")
I got them from [https://www.aliexpress.us/item/2255801134833289.html](https://www.aliexpress.us/item/2255801134833289.html) sorry, can’t go find them and take chipset pictures for you now, but they are ABC and work with the lib [Previous page](https://rpi-rgb-led-matrix.discourse.group/t/solved-aliexpress-2-string-passive-adapter-not-working-because-rpi-connector-was-soldered-on-the-wrong-side-of-the-board/892.md?page=1)