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Join Date: Nov 1999
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I decided to start a new thread for this so it can be found more easily in a search.
My experience designing IC chips since the mid 70's leads me to suspect that there are defective ICS on the board in the Video generator circuit that cause the heat up blue sparkly problem. Any of the ICs could contribute to the problem, but the particular ones would be the Ram, DACs, or Decompression chips.
I have found a part number to order the Service Guide for the TUDST-50 and TU-DST51A. These are not full service manuals, but they are reported to have schematics and troubleshooting flowcharts including that magic number for the test pattern display, and be about 30 pages in length.
I ordered them and was told they are on back order for 6-8 weeks.
Here are the publication numbers, these aren't the order numbers, but with the model number and this publication number I've finally got Panasonic to cough up service literature for these beasties.
TU-DST50 publication number MTC9901791C1
TU-DST51A publication number MTC9906034C1
Maybe if enough of us order these, they will actually print them and ship them.
The phone number to order parts and manuals is 800 833 9626. The manual for the PV-HD1000 is now available.
Putting all the info in one place, the service menu with test patterns is accessed by selecting Display, and then highlighting Backdrop, and entering the magic number 728412 on the remote. While that number is entered there is no indication that it is being accepted.
After the entire string of numbers is entered, the video output stops for a few seconds and then the service selections appear. Of particular interest is the video check that is actually a test pattern diplay of a vertically split screen (on the TU-DST50) with color bars on the top and a multiburst on the bottom.
The multiburst was reported to extend out to about 2000 pixels resolution in the right most box. The box just to the left of that has 1000 pixels resolution. A true 1080i display would be able to display the 2000 pixels box with the same clarity (alternating white and black lines) as the other boxes. On my UM monitor, the 1000 pixels section is fairly clear and within the 2000 pixels area I can make out that there are about twice as many vertical lines as in the box before, but I am seeing color convergence and shadow mask artifacts there.
As I had suspected, the UM is certainly good for the 1280 pixels needed for 720p, and I am able to see that 1080i feeds have more horizontal resolution on my UM monitor even though the resolution is attenuated by the screen characteristics.
Someone with an YPrPb to RGB converter and hi res monitor (such as a computer monitor or 19" or 21" can probably see the 2000 line display clearly, even if they didn't have a larger true 1080i capable box.
It would be very interesting to hear which HDTV products have the capability to clearly display the doubling alternating white and black lines in each of the boxes.
As it was reported that the Panasonic STB's output is attenuated at the highest frequency box on the right side, it would be normal for a true 1080i display to have the white lines not be as white and the black lines not quite as black as the box immediately to the left, but the lines should be clearly visible and there should be twice as many as in the box immediately to the left.
I can confirm that the value displayed by the IEEE1394 test in the service menu does in fact display the unit's bus address that it reports to other IEEE1394 devices when queried electronically. I have access to equipment that can display those electronic IEEE1394 bus queries.
There is no reason for the user to modify this number. It is most likely that this provision was included in the service menu so that after the STB was manufactured, Panasonic could enter a unique number into each box.
About the Blue Sparkly problem- Panasonic knows of this defect. Even if the unit is out of warranty or second hand I'd complain if they charge very much to fix this.
I talked to the Digital Products and Projection TV group that handles the STB support, at telephone number 888-843-9788.
For an out of warranty repair the typical repair charge is $50.00 according to Panasonic. Ship the unit to:
Panasonic Factory Service
1705 N. Randall Road
Elgin, IL 60123
direct phone numbers:
Include a check for $25.00 with the out of warranty unit for their evaluation fee that will apply to the repair charge.
Call the 888 toll free number above to verify that this information is current before sending.
After I get the service guide and schematics, I will probably be able to identify which IC(s) are potentially bad causing the blue sparkly problem. It may turn out that these chips are custom to Panasonic, especially the MPEG decoder, and it may be cheaper to let Panasonic fix the box.
In any installation that uses that Panasonic STB, it is important to provide adequate circulation around the unit, and not block the air holes. In my own cabinet, I mounted a small muffin fan through the back and a suspend the TUDST-50 with 1/2" wood strips under its feet. There is a clear air space of 1.5" above the unit, but my added fan keeps the enclosure cool.
There is an audio playback problem when the Toslink output of the TU-DST5x is connected to many brands of Dolby Digital decoders / amps particularly when tapes are played with the PV-HD1000. The problem manifests itself as random muting or clicks and buzzes occuring during tape playback while there is no corresponding visible video dropout. The problem occurs at random places and is not associated with an actual dropout on the tape, but is likely a problem in the firmware or toslink chips inside the STB. The solution involves the use of a Pansonic / Techniques brand outboard decoder or integrated decoder / amp, or a high end decoder that is able to mask the glitches. The glitches do not occur when the tape is played through the DTC100 with the 169time.com DVHS option 1 or 2 that permits such playback. However, the 169time.com equipped DTC100 is not a drop in replacement for the Panasonic STB since the DTC100 has RGB outputs, and can only record to the PV-HD1000 when an option 2 equipped unit is used.
"With Liberty, HDTV and Justice for all."
"With Liberty, HDTV and Justice for all."