Sony mfm-ht75w no speaker sound when in computer mode

Press the volume + or - key from TV local control Panel

Please clarify whether the entire tv powers off or only the screen turns off and you can hear the sound so that we can continue with the diagnosis. Sony LCDs are notorious for backlight inverter failures.

Your laptop may very well have a function key that turns the VGA socket on at the back of the laptop.
Also you will need to check in display properties that the secondary monitor is enabled.
If you need more help post a comment with the make a model of your laptop.

You don't write which operating system you use, but generally you should be able to choose where the sound output goes in the Sound Properties in Control Panel.
If however Sony decided to put some special software that does the thinking for you, and directs the sound output via the HDMI when connected, then you have to dig deeper...

here is a link to Operating Instructions

Hi Leonardzap

Can you advise if you found a solution to this problem as I too have this screen and it is cracked

thanks

Sony style has an e-support system that provided the information I needed. It was obviously FREE!

Hi,

I am assuming that you are referring to the same monitor working only if the PC is in Safe Mode but not in Regular Mode.

This is possibly due to the Screen Resolution and/or the Refresh Rate Settings of your Video Card to way too high for the monitor. While in Safe Mode lower these settings in your Display Properties.

.Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.

SONY MFM HT75W

Hi, I was able to fix my set by changing only three out of the six capacitors between the heat sinks opposite the plug on the board. I noticed under a microscope the caps looked a little puffy, but not much, and I checked them with a capacitance meter, but they were in tolerance, but decided to change the three closes to the edge of the board with a 1000uf, 50v, 1000uf 25v and 1000uf, 50v with the one that is 25v going in the middle, I didn't have another 1000uf,50v for the middle one. (sometimes you gotta use what you got to get what you want) So I powered my set up and it stays on . I hope this helps. I may go back and replace all six with 1000uf, 50v, but the space in there is limited and those are some large caps. I will wait until the set acts up again before i do that. I am satisfied with it for now. Again I hope this will help with what you've got going on with yours.