Just a quick teardown today, we’ll be looking at the Tenda 8 Port Fast Ethernet Switch – I’ve never heard of this manufacturer before.
2 screws later and we’re in.
There’s not much to it as you would expect but it has an IC+ IP178D which is similar to the IC+ part we saw on the last teardown, it’s just an 8 port switch controller.
Also the “diodes” close to the power supply input don’t seem to be diodes at all since there was no voltage drop, probably just some input protection. There is also a DC-DC converter (MC34063A) on the right of the board.
The diode-shaped parts next to the power plug are most likely ferrite beads. Those are used to filter high-frequency noise from the voltage rails. I suspect they planed on using a AC PSU, but later on decided to get a DC plug instead – maybe because it was cheaper at the time.
There is one nice detail about the buck-converter based on the MC34063 (U3), as they didn’t use the integrated BJP for switching but added a MOSFET (U2) with a discrete gate-driver circuit (Q2, Q3, D14).
Ah that makes sense about the ferrite beards and thanks for the extra information 🙂
I’ve got one of these as well. But mine had “7.5VAC” printed on the case. I seem to have misplaced it…. so when I opened mine up and saw the diode bridge, cap rating, and a DC-DC converter, I supplied it with 12VDC and moved on with my life. Still working….
Glad I stumbled upon this discussion. Thanks for the tear-down shots.
In a re-org of my patch panel the power supply got separated from the unit. After matching everything else up, I’m left with this 12V one branded Delta Electronics (Thailand). The label on the base of my Tenda G1008D switch says 9V power. Steve’s comment suggests I’d be fine using it, or it might even be the right one – interested to know brand power pack yours came with, if only to solve the mystery!
I actually don’t know what the power supply that originally came with it either, but I have powered it up with a 12V one and it turns on fine.