HDMI Switch teardown

29 Jan 2017

Something different this week, a teardown of a cheap HDMI switch. To be honest there’s not much inside, as you can see from the picture.

HDMI Switch PCB

On the left (in orange) there’s a 3.3V regulator.

The top left (in blue) is an unmarked part, but as it’s connected to the IR sensor, has a programming header and is wired to the I2C input of the HDMI switch it’s probably a generic 8-bit microcontroller.

The main part, in the middle (in red), is a PI3HDMI2410. It’s a dedicated HDMI switch that does everything you need. However, the specs don’t match what is claimed in the products manual and on Amazon’s page.

The manufacturer states that the chip supports HDMI 1.3, but also say that it’s ‘HDMI 1.4 data rate ready’. As the datasheet for the part is dated late 2009, around the time the HDMI 1.4 spec was released, this isn’t too surprising as certification probably hadn’t started yet. This means that while the part might be able to cope with 4K it’s not guaranteed. Stranger still is where they say that ‘The maximum data rate support is up to 5Gbps which can meet HDMI 1.3a standard’, but 10Gbps seems to be the starting point for 1.3 not 5.

As I’ve just brought this so I can share a HDMI port between the living room PC and the Nintendo Switch when it turns up 1080p is fine by me, but anyone buying this hoping for more might be disappointed.

As there’s so little inside the switch I thought I’d pull apart the power supply as well.

HDMI Switch Power supply

It’s pretty much what you expect from a cheap chinese supply, a transformer with a generic and impossible to find controller chip. On the up-side, they’ve made some attempt at isolation between the high and low voltage sides, but I think there was supposed to be a suppression capacitor across the transformer which they’ve helpfully left out.