Home Theater Questions? Ask a Technician for Answers ASAP
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, the described symptom almost always point to an internal hardware issue.
Are you then considering a DIY (do-it-yourself) repair approach? If yes, do you have access to and familiar with a multi-meter and even a soldering iron?
Great on the DIY!
For starters, can you try re-soldering (if have not been done) the HDMI pins particularly "...Two of the HDMI inputs..." ?
Please click HERE.
The re-soldering would be a preliminary step both as an attempt of a fix and as a test by process of elimination or even just to rule these pin solders are a potential suspect.
Thereafter voltage checks would have to be made after the connections have passed re-soldering/checks.
And yes please; when able.
For these type of soldering requirements, a hot air solder station is preferably used. Something like the product shown HERE.
And yes, the PCB (printed circuit board) would have to be dismantled/removed to gain access to the trace /solder side.
Would you need dis-assembly instructions?
Another potential suspect to check would be failed capacitors.
Incidentally, are both audio and video non functional if using the above HDMI ports?
Yes, the SMD (surface mounted devices) capacitors would have to be de-soldered to enable checking out-of-circuit and soldering it back in or its replacement.
I realize that the above information may perhaps be not what was expected. Unfortunately, there is no quick-n-easy fix and neither is there a workaround; sorry for having to be the bearer of bad news.