Why does one HDMI cable work but not another?

[AJL308]

Someone gave me an Optoma HD projector the other week - love it.

Anyway, when setting it up to operate from my laptop I discovered a strange anomaly; I have two essentially identical HDMI cables. This is the one...

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2...

....but only one will drive the projector. The first cable I've had about a year and I use to run from the laptop to the TV so I can watch movies from the hard-drive. This one works fine with the projector and is 10m long.

The second cable is new today and is identical to the first (same specs and everything) but is 5m long. This cable won't drive the projector. The projector just gives a "no signal" message.

These cables are identical apart from length. I'd be less surprised if it were the longer one which didn't work but it isn't. Anyone know what's going on here

[NorthDave]

I'd say that the 5m lead is faulty and has a physical break. I'd return it.

[AJL308]

The 5m one feeds the TV from the laptop no problem.

I tried another HDMI cable last week which didn't work the projector either but assumed that one might have been an older spec or something.

[anonymous-user]

Some cables dont' fully function over longer distances. So what you get from one 2m cable, might not be the same from a 5m version of the same cable.

It's all down to quality. I have a 10m HDMI running my projector fine.

I have 2m HDMI cables that make my NVidia shield flicker, and 2m HDMI cables (more expensive and thicker) that don't. The cheapo 2m cables work just fine for all my other (1080p) devices, but no the Nvidia (4k) device.

[AJL308]

RogerDodger said:

Some cables dont' fully function over longer distances. So what you get from one 2m cable, might not be the same from a 5m version of the same cable.

It's all down to quality. I have a 10m HDMI running my projector fine.

I have 2m HDMI cables that make my NVidia shield flicker, and 2m HDMI cables (more expensive and thicker) that don't. The cheapo 2m cables work just fine for all my other (1080p) devices, but no the Nvidia (4k) device.

Thing is though is that it's the shorter one of the two "identical" cables which doesn't work. The 5m one won't work but the 10m one will. Same make, same model, same quality but only the long one will work. As I say, the shorter one works to my TV no problem but not to the projector.

The cable IS doing something because I have my laptop set to only display on one screen (in this case the projector) not on the laptop screen as well. When you plug in the cable the laptop recognises the projector as it turns its own screen off but the projector gives a "No signal" message.

[Brother D]

Had this recently - two HDMI cables went faulty within 3 weeks of one another. They were working fine for 6 months running from a PC to the monitors then both went bad. TBF they were amazon basic ones, but still amused that a cable can 'wear out'.

Must have worn out the electrons.