How do i scan for channels on my hitachi RC A48105. I do not have a manual

Yes, connect external antenna to your tv.

The main system control memory IC to this set is faulty. Check and replace it. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/

try the following website:

http://www.manualagent.com/hitachi/57s700/owners-manual

then see pages 51 thru 54 regarding channel scan

Unfortunately, you need a set-top box. The Hitachi 65F59 has an ATSC (digital OTA) and NTSC (analog) tuner. It doesn't have a clear-QAM (unencrypted digital cable) tuner.

There are a few DVR set-top boxes with QAM tuners that you can buy separately. (You will need to make sure a given model is compatible with your service. FIOS uses a different option on the Cable Card than other providers.) Alternatively, you can get a cable box from your company.

Retrevo has the manual for this Hitachi TV here: http://www.retrevo.com/support/Hitachi-65F59-TVs-manual/id/371ci977/t/2/ . You will need to enter a code to access the PDF.

If you want OTA HD, you will need to determine the correct antenna for your area and the direction to the transmitters. (External antennas pick up more stations. In some areas amplification may be needed to get a good signal.) See antennaweb.org or tvfool.com for searches on the appropriate antenna to get a signal and where to point the antenna. Antennaweb assumes an external antenna but is very conservative in the received channel list. You would need to set the TV signal input to Air and rescan for channels if you choose to go with the OTA signal.

I wish that I had better news for you.

Cindy Wells

are you sure it is a 2856? I've narrowed your manual down to this page http://www.retrevo.com/samples/Hitachi-TV-manuals.html#a
If you're trying to get channels from the air, switch the input to air/tv (varries depending on brand) Then in the general settings, should be an option for 'run auto scan'
wish i could be of more assistance

[PDF] 32LD30UB 32LD30UA - Hitachi European Service Sitewww.hitachiserviceeu.com/scripts/userguide.php/32LD30UB_EN.pdfFile Format: PDF/Adobe Acrobat - View as HTML
32LD30UB. GB. Instructions for use .... Electronic Programme Guide (EPG) .................... 20 .... Manual Channel Scan ............................29. Clear Service List (*) .THIS LINK ABOUT IS ALL YOUL NEED TO GET A FULL 58 PAGE INSTRUCTION MANUAL FOR YOUR SET, IV JUST AN HOUR AGO PRINTED THE SAME DOCUMENT MYSELF, HOPE YOU CAN GET YOUR PROBLEM SORTED NOW. X

that is the way that model is supposed to work it is an early HD model You will just have to write down what your favorite channels fall on

Do you have the tuner locked out for use of HDMI input only?
Most of the time when a selection is not able to be hi-lited it is
because a feature that is activated locks out other selections.
Hope this helps,
Skyassoc

Have you checked your aerial is connected? It may be necessary to do a manual re-scan. Make sure you choose the option to 'replace' current channels.