WTB: Ubiquiti PoE Edgeswitch 48 flash chip MX25L25645G - Page 1
Forum section: electronics / general

author: vk2amv
author_rank: Unknown
timestamp: June 01, 2025, 01:05:13 pm
content: Hi,I am hoping someone can help me out here.I have a Ubiquiti Edgeswitch 48 500w PoE model that suffered a lightning strike.Luckily less damage than expected.I managed to repair it, and it is booting up again and actually mostly works.However one of the parts that required replacement was the main flash chip, and this is my problem.What happens is the switch boots up fine, however it shows error A12 and drops its config and PoE stops working after 45 minutes.After a bunch of research and screwing around, it turns out the switch thinks it is non genuine.The reason I believe is the required factory serial number is not set in the replacement flash chip, so the switch is erroring as non-genuine.This is a serial number that can only be set and locked by the factory so I cannot just clone a chip from a working Edgeswitch.I need an original flash chip from another 48 port PoE Edgeswitch. (I am actually reallly annoyed at myself as I recently threw out 2 dead Edgeswitches, and one of the few useful parts I didn't save was their flash chips)I am hoping someone out there has an Edgeswitch that has a dead CPU or network chip or some other fault that they have been ratting for parts, but still has a working MX25L25645G flash chip I could buy as I would be very appreciative.The flash chip I need is on the bottom of the motherboard BTW.TLDR:If someone out there has a faulty 48 port PoE Edgeswitch (As long as the fault is NOT error A12) that still has a working Macronix MX25L25645G flash chip I can buy it would save a perfectly fine Edgeswitch from turning into a parts unit.

author: thm_w
author_rank: Super Contributor
timestamp: June 04, 2025, 10:18:04 pm
content: Probably too expensive to ship:https://www.ebay.com/itm/335853361782But looks like there are quite a few failed units with various motherboard problems.

author: vk2amv
author_rank: Unknown
timestamp: June 06, 2025, 12:21:09 pm
content: Thanks for that.I actually did see that one.Unfortunately shipping to Australia is over USD$100.Not worth me spending that much money on a switch that I am not in desperate need to repair it to service, but purely for the benefit of saving it from the spare parts pile.

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 06, 2025, 03:50:41 pm
content: Quote from: vk2amv on June 01, 2025, 01:05:13 pmyou are right, I try to clone the chip, and even all the OTP area copied, but stiil A12 error, are you sure the main program check the SN of the chip ? BTW, if you need the UBNT swith, I can help you buy it, then get the chip, main to you. for the UBNT POE, I can replace any part except the flash eprom, the HW design of UBNT is poor.

author: sigsauer
author_rank: Newbie
timestamp: September 02, 2025, 08:21:22 am
content: Hello!The SMPS has blown. TEA, Q5, and R5 have already been replaced, but I can’t see the values for these components as they got burnt. I’d be grateful if someone could provide them.As for the diode, I assume it’s an A4 C. Could BAT54C be used instead?Thanks in advance!

author: dizzyadam
author_rank: Newbie
timestamp: October 14, 2025, 06:02:07 pm
content: Quote from: testpoint1 on June 06, 2025, 03:50:41 pmI had an experiment with UniFi APs which also suffer from the same A12 error with a bad BIOS.Issue:A12 Error when SSHd into the device.Tried:1:1 cloning dump from "Bad" bios to new chip from Aliexpress = A12Modded dump from working bios to new chip with corresponding MACs and checksum code (6 characters after MAC on the label) = A12Transferring working bios chip from the same model UniFi AP = Working but showing the MAC of the unit that I transplanted from - This was surprising as I thought it would cross check with what the radio's physical MAC was.Cloned the working bios chip to a new chip from Aliexpress = A12Conclusion:It's given me hope that I can transfer a bios chip with no modification from a known working unit with no issues. However, there must be something missing during the modification of a bios dump, maybe another checksum or there could possibly be a hardware identifier of the chip that needs to be changed within the dump.Or maybe I got a bad batch (I tried new chips each time I did written modded dumps) or fake BIOS chips from Aliexpress - unlikely since I can read and identify all as that model in my programmer software.Hoping someone has more time to look into this and give us hope.

author: aeg
author_rank: Regular Contributor
timestamp: October 14, 2025, 10:53:42 pm
content: Is bit 0 of the MX25L25645G's security register set on the UBNT part? Only Macronix can set that bit.