Recently I have acquired some faulty Mikrotik Routerboards (RB 433 etc.). After few minutes of inspection it was clear all ethernet ports are broken on the board. One ethernet port connector has also been physically damaged. I have removed the broken connector to be 100% sure it doesn't cause short circuit. Other ports were in partially working condition, but they produced heavy packet loss (50-80%). The conclusion was the ethernet controller chip is broken. The manufacturer is IC+, part type is IP 175 (C/D).
|A broken routerboard|
So I have desoldered the broken chip from the faulty board and the good chip from the donor board (which was also hit by a thunder, but fortunately only the PSU module has been damaged).
|Donor board: the ethernet controller chip has been removed|
|Ethernet controller chip IP 175|
The next step was to solder the good chip to the board to get repaired.
|Mounted chip on the "better" board|
After powering up the system all ethernet ports worked immediately. The packet loss has disappeared.
|Repaired RB 433|
|No more packet loss|
This was a short description of the steps to do in order to repair a such board. Required tools and parts are:
- Broken board to get repaired
- A donor board
- Temperature controlled soldering station (Weller WTCP 50 or similar)
- Desoldering wire
- Good quality flux
- Isopropyl alcohol for cleaning up the board after desoldering and soldering the components
SMD soldering is a tricky thing, it requires lots of experience to complete it successfully. Do it on your own risk!