Last Update
9/5/2003 Event ID E08914573 

Model
GENTVP, KD34XBR2, KDP51WS550, KDP57WS550, KDP57WV710, KDP57XBR2, KDP57XBR2, KDP65WS550, KDP65WV710, KDP65XBR2, KDP65XBR2, KE32TS2U, KE42TS2U, KE42XBR900, KE50XBR900, KF50XBR800, KF60DX100, KF60XBR800, KLV30XBR900, KP43HT20, KP43HT20, KP46WT500, KP46WT510, KP51HW40, KP51WS500, KP51WS510, KP53HS20, KP53HS30, KP53XBR300, KP57HW40, KP57WS500, KP57WV600, KP57WV700, KP57XBR10W, KP61HS10, KP61HS20, KP61HS30, KP61XBR300, KP65WS500, KP65WS510, KP65WV600, KP65WV700, KP65XBR10W, KV27FS100, KV27FS200, KV27FS210, KV27FV300, KV27FV310, KV30XBR910, KV32FS100, KV32FS200, KV32FS210, KV32FV300, KV32FV310, KV32HS500, KV32HS510, KV32HV600, KV32XBR400, KV32XBR450, KV34HS510, KV34XBR800, KV34XBR910, KV36FS100, KV36FS200, KV36FS210, KV36FV300, KV36FV310, KV36HS20, KV36HS500, KV36XBR400, KV36XBR450, KV36XBR800, KV40XBR700, KV40XBR800 

Subject
HDTV signal source causing a 3 inch border, on the top & bottom, and both sides as well.
 
 

SYMPTOMS

Customer believes he is not getting HDTV signal from HD cable box. No one was able to explain why a HDTV signal source was causing a 3 inch border, on the top & bottom, and both sides as well.

  

CAUSE
We need to look at this further. There are 1080i broadcasts with 4x3 aspect ratios. The 18 flavors of the ATSC spec for 1080i/720p states that the scan shall be 16x9, not necessarily the video. Some stations are broadcasting the signal as  1080i/4x3. Also, they can broadcast the signal in letterbox format plus some of our TV's as well as some cable/satellite boxes allow the signal to be formatted in letterbox.

When postage stamp displays have appeared in the past it has been caused  by upconverted 480i to 1080i with the aspect ratio set to 4x3 and letterbox set somewhere along the display lines (see above for possibilities).

What model of TV does the customer have?
What model of cable box? Some cable boxes and sat boxes will  have a variable out setting to allow for 480i/1080i signals.
What cable provider?
What channels? Are the channels upconverted 1080i or true HD? Are they over the air ATSC signals being remodulated via the cable company or are they coming from the  cable companies own carousal?

  

RESOLUTION

During the conversation with the customer, I was able to make the determination that the HD cable box was hooked up to the tuner input (not the HD input for this set), and also Video 5. When the customer views the image from the tuner on channel three,  he receives a good picture, but not HD. When he switches to the correct input for a HD signal, video 5, the image then has a black border all the way around. The problem was this with Video 5. The HD cable box continually outputs a 1080i format signal to  video 5, and the TV properly responds to this signal by reducing the vertical width to a 16:9 format, thus causing the letterbox effect with black borders on the top and the bottom. The cable company is taking this one step further when they convert a  4:3 standard analog signal to 1080i, (1080i only runs in a 16:9 format), the 4:3 standard image cannot fully fill the 16:9 1080i format, so the left and right sides are left blank. I described this over the phone to the customer, and he fully understood  what was taking place. (It is much easier to explain this verbally than it is to put in writing).

Solution:
Customer is now fully aware of the two different formats of video. If the signal is a standard definition 4:3 image, the customer will view  this through the tuner on channel 3. Only with a true HD program did I advise the customer to switch to video 5. The customer is aware that a black border will occur on the top and the bottom with true HD video fed to Video 5, but with a true HD  program, it will fill the screen fully left and right. I also advised the customer to contact his cable company and see if they can supply a converter box that will switch the source to input 5 automatically between standard analog, on a 4:3 non HD  program, and full 1080i, when a true HD signal becomes available. 
