[TechAssist] Re: Sony KDP57XBR2 Picture shrinking all 4 sides
- From: "Gemini Computer & TV" <geminitv@xxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Fri, 2 Apr 2004 12:32:53 -0500
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.
Bob Waterman, CET® #RI-28
Master Technician License #9109
Service Manager / Parts Manager
Gemini Computer, TV, & Security Alarms
(508)695-7302
(508)695-7769 FAX
geminitv@xxxxxxxxxxx
geminitv@xxxxxxx
www.geminicomputertvsecurityalarms.com
----- Original Message -----
From: "Shoreline Electronics" <jstielau@xxxxxxxx>
To: "Tech Assist" <techassist@xxxxxxxxxxxxx>
Sent: Friday, April 02, 2004 11:23 AM
Subject: [TechAssist] Sony KDP57XBR2 Picture shrinking all 4 sides
>
> Make : Sony
> Model : KDP57XBR2
> Serial # 9001388
> Problem : Customer states that picture is shrinking from all 4 sides.
>
> We are going out work on this one in a couple hours from now........any
> bulletins that may apply. Planning on looking for cracked/loose
connections
> in power supply and sweep circuits.
>
> Is this a light box or does the top section remove in case we need to
> transport it back to the shop?
>
> =================================
> Jeff Stielau
> Shoreline Electronics Repair
> 344 East Main Street
> Clinton,CT 06413
> (860)399-1861
> (860)664-3535 FAX
> jstielau@xxxxxxxx
> =================================
>
>
> --------------------------------------------------------------------------
---
> Lost Password:
> http://www.tech-assist.org and select "Login Problems?".
> Email Archives:
> //www.freelists.org/archives/techassist/
>
-----------------------------------------------------------------------------
Lost Password:
http://www.tech-assist.org and select "Login Problems?".
Email Archives:
//www.freelists.org/archives/techassist/
Other related posts:
