I have a Acer win7 laptop with ATI HD5650 graphics and an HDMI output. For 2 nights I connected this to my new PAnasonic VT42 Plasma TV via HDMI and watched movies. The 3rd night, without any changes being made to laptop or TV, the TV did not see any signal. Neither will the TV see any VGA signal from this laptop. I have tried everything to solve this problem: alternative HDMI cables, tried all the HDMI ports, the bluray player works with both HDMI cables tried. I took the laptop into Dick Smiths and it works through all HDMI cables on other TVs, but, when tried on other new Panasonics it does not! The laptop has 3 ways to change the output between displays; win button + P, Func + F5, and via the ATI Catalyst Control Centre. I have tried all these and also returned the card to its default settings a couple of times. Another laptop I have has a S-vid and VGA output, these work on the TV. The only thing I haven't tried is another HDMI laptop, I do not have another. So, The TV will show some outputs from laptops but not HDMI (now) or VGA from mine. The Laptop will output via HDMI to other TVs but not to at least 3 other Panasonics in the local store. Any ideas?
I'll go out a subject a bit to explain something very similar. I got a PlayStation 3 that's doing basically the same thing:
When using any other cable than HDMI it don't show anything on tv. when using an HDMI cable it may show nothing OR it shows horizontal lines OR the screen is shaking absurdly OR it's wiping from bottom to top endlessly. Using HDMI it works on select LCD only. I don't have access to any Plasma to try it on. I'd say it works on 1 tv set on 3 by using HDMI... After been on that case for long enough, I guess the graphic card inside it is doomed.
Hope that your graphic card is not at the end of it's life cycle. You should try another graphic card if you can just to see how it will act. Also you should use that software:
and uninstall with it any display driver you see, then install the latest driver. It shall correct the problem if it was driver-related.
If it was my computer, I would try all of these in this order: the latest driver from ATI, latest driver from ACER, then the driver that came originally with the laptop (since it is supposed to have been tested by ACER for compatibility between graphic chip and the select driver before being sold out, doesn't it make sense ^^). Using Driver Sweeper between each install is mandatory.
If softwares don't resolve that, it could be a hardware failure in which case there isn't much to do. You could always try a reinstall of Windows (that suppose that the windows installation present on the backup partition isn't corrupted at all for it to work properly).
Also since I don't use HDMI on my computer (which means I don't know much that technology other than having a xbox360 and PS3 at home using HDMI only when going at friends house on their LCDs) I'm wondering: do you have to have both the graphic card HDMI and the tv set HDMI to be the same revision to work ? if anyone could give a little info on that, maybe that is the black sheep that's preventing us from using HDMI peripherials on some tv sets.
Thanks. I will have a look at drivesweeper. Re the HDMI revisions, I just can't see why it worked for 2 nights then stopped... I called Panasonic service company locally and they didn't have much help to give other than to suggest that the new HDMI versions are supposed to be capable of modifying/switching off your connected hardware if it detects non-copyrighted material being played. I think he's dreaming, surely that'd be illegal to allow remote software to make decisions and disable your owned hardware and software in some way.... I've held off updating the TV HDMI until I find out what the newest version is capable of. My laptop is only 12mths old so hope the graphics card is ok. Maybe someone will know of a definite acer/panasonic compatibility issue..