All this information is under it is nice to know but how does it help the installer or home owner diagnose a problem with their system? It doesn’t! We need to discuss some troubleshooting techniques that help us in the real world. I try to keep it simple and get it down to two areas, signal problems or equipment. To test the signal here is what I do.
Get all the components next to each other and connect the system with DPL rated cables all under 2 meters or less. There are many inexpensive brands of cables that have passed DPL certification and worth it for an installer to have some at least for troubleshooting. Plus I’ll give a shameless plug for Brent’s Ethereal cables for all his help on the forum. I’m sure Brent and Jeff can tell you there are some short cables that are poorly made and can cause problems, so don’t assume any short cable will be fine.
If the system works with certified short cables but not with longer cables than it is a signal problem plain and simple. Do whatever you need to do to fix the signal, ie. Balun, signal restorer, etc.
If it doesn’t work with the certified short cables is where it gets interesting. Now, we have to figure out which device is causing the problem. First check and try all the device settings for each device. Simple things like turning off CEC, monitor check functions, set one resolution, make sure it is sending 8 bit by turning off deep color, Use video levels instead of RGB, etc. If this doesn’t fix the problem than it is time to swap equipment. I can tell you there is a big variance of cable/sat boxes even of the same model so changing sometimes solves the problem. I could check the voltage coming out of a device with my multi-meter but this might not be the problem but easy to do. I rarely take my oscilloscope to the field, and just not practical as I can only look at one channel at a time and don’t have the money to upgrade my equipment to do eye patterns. Even if done in the shop (my house) you won’t believe how much time you can use testing equipment. Like I said just not practical.
If you have a DAD or signal restorer put it at the output of a device. It will give some information like if the voltage and hot plug are OK. It also gives indications that data is moving between devices if placed in the middle but it can be difficult to know which device is causing the problem if you don’t get these indications. So it is not the best diagnostic tool. Hopefully, something will come out that we can test input and output of devices to diagnose the problem. I know Jeff is working on something like that. Quantum Data has a unit that will help and is ~$1500 which I have thought about buying. But still doesn’t do everything I would like, like number of device keys a source has. Also, I’d like something that can do HDMI 1.4 or I will be buying a another device in the near future.
Luckily we haven’t had many HDMI problems (knock on wood) but we use equipment we are familiar with and keep cables <20 feet unless it has corrective circuitry (ie restorer or balun). I’d love to hear what other people do to diagnose problems.
