Had a Hitachi 42HDS69 for 4 months. The OTA digitals channels tuned in at first and worked. Ultimately I connected it to my cable signal and the unencrypted digital channels on the cable tuned in and worked great for 4 months.

Last week the cable digital channels all started displayed as a blank black screen - no channel info or anything. All analog channels were ok. I redid the autotune and as it worked through the process the set found all the same digital channels (and their channel ID NBC-HD etc etc) as had been there before but once the scan was complete the channels still display as a blank screen.

I then decided to reconnect it to the rooftop ariel which had definitely worked when I first got the TV. Same thing - during channel scan it found all the expected digital channels (2-1, 5-1, 5-2 etc) but selecting these channels gives only a blank screen. Analog OTA channels also work normally - just no digital.

Hitachi claim this is a cable provider issue - though they have no explanation for the apparent simultaneous loss of OTA digital channels. They are sending a firmware upgrade but I don't expect this to fix the problem. Does anyone have any ideas?

:( :(

I'm confused as to what currently works for you and what does not.
If you are using your antenna and not your cable connection get you get the OTA digital channels? If yes why would Hitachi say it is a cable issue since you are not using cable.
Or are you saying that you can no longer get the unencrypted digital channels from your cable provider using your QAM tuner.
Or are you trying to connect the cable signal and the antenna signal in parallel and feed that to your TV? If yes this will not work since the the OTA UHF digial channels often use the same UHF channel for a totally differnt analog program on cable.

Do a scan with nothing connected to the input to clear out anything in memory. Then do another scan. The issue on cable could be complicated by the fact that the cable co moved/encrypted some chs. The OTA issue is a bit more worrisome.

Also, let people know where you live. A visit to the local OTA forum will often give you some better info, as well.

Ok, thanks all for the comments. This is zip code 60056, NW Chicago Suburbs IL. I am using only the Cable signal OR the Antennae signal at any one time. Last September I could get digital channels on both cable (Comcast expanded basic analog) and antennae. From September through February I watched the digital channels from the cable signal then they stopped working in early February - just a blank black screen on all digital channels. I then reverted to the antennae and found I no longer got digital channels on that either. I get all analog channels on both sources.

Clearing the memory and doing a channel scan with nothing connected the TV finds no channels. With the cable connected the channel scan finds many digital channels BUT they are all sub-channel -1 and none of them display a picture once the channel scan is complete. What I mean here is that it finds channels 92-1 93-1 94-1 99-1 100-1 101-1 102-1 103-1 all the way up to 126-1; everything it finds ends in -1 whereas previously many of the digital channels had been -4, -5 etc. All of the channels it does find give a signal strength in the 87's with SNR of 76 - numbers much the same as when the digital channels actually worked. But they all now give a black screen.

With the antennae connected the TV finds a few digital channels. These also all end in -1, there are no sub-channels (-2, -3 etc) like I had back in September 2006. The channels it does find on the antennae are unusual higher up numbers, not the local NBC, CBS, FOX channels that I had originally from the antennae. Like the cable signal, the channels it does find display a black screen once the channel scan is complete.

Hitachi have yet to send the firmware upgrade but I'm doubtful that will make a difference. They have suggested getting a local engineer out under warranty but I'm concerned that I really don't have digital channels coming in any more and I end up paying for the visit. I'm not sure how the OTA signals could go away but I suppose the answer would be to find a way to prove I definitely get OTA digital TV. Buy another TV with an ATSC or QAM tuner perhaps?

I am a fairly thorough technical person but this issue has me really confused. I will be very interested in any comments anyone has.

You already know the antenna worked for local HD. Assuming the antenna still works properly, the HDTV should receive the same local HD channels it did before.

Since both sources (cable & antenna) are having the same problem (tunes but has black screen), it sounds like the HDTV tuner is having problems. Is there a way to reboot the tuner; e.g. disconnect the power, etc.?

[QUOTE=ronmcrae]
The channels it does find on the antennae are unusual higher up numbers, not the local NBC, CBS, FOX channels that I had originally from the antennae. Like the cable signal, the channels it does find display a black screen once the channel scan is complete.

QUOTE]
The digital channels are in almost every location be broadcast over a UHF channel.
And the standard analog channels for the Networks, 2, 4, 5, 7 etc are still broadcasting SD analog in NTSC format.
The networks do not always also transmit over their digitalk sub-channels -2, -3, -4 etc since it requires more bandwidth and more transmitter power to do so especially when they are tharsmitting using ATSC HD resolutions over their -1 channel.
Check TitanTV.Com to find out what digital channels are currently available OTA in your location.

Sure sounds like the digital tuner went bad. OTA should not have changed.

The networks do not always also transmit over their digitalk sub-channels -2, -3, -4 etc since it requires more bandwidth and more transmitter power to do so especially when they are tharsmitting using ATSC HD resolutions over their -1 channel.
Check TitanTV.Com to find out what digital channels are currently available OTA in your location.

It doesn't take any more power to broadcast additional channels and the bandwidth is always 19.39 Mbs regardless of how many sub channels. You are correct that HDTV does take up a much larger portion of this bandwidth than an SDTV channel would.

Back to the tuner problem:
Your tuner may have selections for AIR or CABLE which would have to be set appropriately. The cable option may also offer sub-options of STD, IRC and HRC for which you would most likely want to select STD. If your setup for the tuner has already been checked as being correct then it is quite possible you have a problem with the sets digital decoder.

Thanks to all who commented. I wanted to give a follow-up. After about 3 weeks Hitachi sent the 119 firmware upgrade which they insisted was done before they would authorize any warranty repair. The upgrade made no difference. The repair center ordered up a replacement digital tuner, came and fitted the card and lo and behold everything worked again.

This all took place after about 6 months of daily use.