Repair LAN ports on router - Page 1
Forum section: electronics / repair

author: Doppler
author_rank: Newbie
timestamp: September 29, 2015, 10:13:59 pm
content: Hello,I'm not willing to give up on this device. The problem started after power outage. Router works fine (sort of). It boots. I can see its wireless networks. I connected it to serial port and I can see booting process.LAN ports are problem!! Their LED's are always on and I cannot connect PC to it.What part of hardware I need to inspect to solve my problem? PLS help. I'm willing to provide any information you need.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 29, 2015, 10:27:24 pm
content: It helps if you provide the make and model number. After that, see if there are any instructions on the Internet to do a software reset to default settings or a way to upload/reflash firmware.

author: MAS3
author_rank: Regular Contributor
timestamp: September 29, 2015, 10:50:17 pm
content: The sticker on the yellow plastic RJ45 array cover tells it is an Archer C7, and Google tells that that would be a TP-Link product.In the centre of the picture you can see a smaller square chip, from which lots of leads lead to the LAN transformers G4812CQ, which then go to the RJ 45 connectors.It will be hard to repair, and i have no doubt that part need to have firmware installed for it to work in that product.There could also be a problem with the power supply to that chip.I'd say that is the part below that chip and at its right, with the 3 capacitors in a row on that picture, but that might as well be the supply to the USB ports next to that.

author: Doppler
author_rank: Newbie
timestamp: September 29, 2015, 10:58:57 pm
content: Quote from: MAS3 on September 29, 2015, 10:50:17 pmYou are right it is Archer C7 AC1750 TP-Link routerSpecifications:UPC: 845973070601 (UPC DB, On eBay)Power: 12 VDC, 2.5 ACPU1: Qualcomm Atheros QCA9558 (720 MHz)FLA1: 16 MiB (Winbond W25Q128FV)RAM1: 128 MiB (Winbond W9751G6KB-25 x 2)Serial: yes, internal, 4-pin header, 3.3V TTLRouter works, I can see its wireless networks. I connected routers serial interface, and with Hypertherminal I can see boot process. There is nothing wrong with processor or firmware, I'm sure. Problem are LAN ports. How can I inspect them?Quote from: MAS3 on September 29, 2015, 10:50:17 pmHow can I check this?

author: Rasz
author_rank: Super Contributor
timestamp: September 30, 2015, 11:51:46 am
content: gigabit switch chip is blownQuote from: Doppler on September 29, 2015, 10:58:57 pmIm affraid asking this question indicates this repair is beyond your abilitiesyou need hot air to swaphttp://www.ebay.com/itm/1x-AR8327-BL1A-AR8327-B-AR8327-BL-AR8327-BL1-AR8327-BLIA-AR8327-BL1A-QFN148-IC-/400970910341?hash=item5d5bba8a85

author: Doppler
author_rank: Newbie
timestamp: September 30, 2015, 01:43:34 pm
content: Quote from: Rasz on September 30, 2015, 11:51:46 amThis chip is very hot.I have hot air rework station, I can replace it... I need to be sure that power supply to that chip is ok!

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: September 30, 2015, 05:50:28 pm
content: Quote from: Doppler on September 30, 2015, 01:43:34 pmMake sure you pre-heat the board for a few minutes, or use a pre-heater, so you don't warp the board, when you use the hot air rework station. It more likely the AR8327-BL1A1 gigabit chip.