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Discussion Starter · #1 ·
Not for SD/HD images, since my NYC TWC is QAM/analog, but as a test to "trigger" my set's ATSC mode. Using a year-2000 Philips 64PH9905 1080i CRT RPTV with built-in NTSC and ATSC tuners. At the moment, switching into ATSC OTA mode only displays "ATSC" on the screen momentarily, then a black screen. A few years back, with my Silver Sensor plugged into DTV ANTENNA, the set would display "ATSC" then immediately try tuning some local OTA channels; (reception in mid-town NYC is very poor). But at the same time, when it worked properly, ATSC mode also provided access to two DTV menus (setup, picture, etc), plus the ability to enter the service menu with a number code. Now, again, it's a brief ATSC screen logo, a black screen, and no menu access.


Yesterday a Philips phone rep suggested trying a different, stronger signal input. Don't want to possibly overload the DTV tuner input with a cable TV signal. But, come to think of it while writing this, my NYC TWC system, back in ~2000-01, used to feed CBS/HBO as RF-modulated ATSC channels--just like OTA--that I tuned via a cable splitter to the set's DTV ANTENNA input.


Lost normal operation with ATSC mode a few years back after removing the rear cover to clean the optics. Besides the ATSC logo display, for a while a few years back there was a fuzzy red horizontal line flashing briefly on the middle of the screen. Now, with the exception of one brief red-line flash this weekend, it's only "ATSC" momentarily then a black screen.


Any suggestions for troubleshooting? I have the CDROM service manual, but schematics aren't that much help. Can't see any loose/broken wires, although a ~2"-wide thin-copper strip linking the metal-cased NTSC/ATSC tuner section to another nearby section is almost completely severed--with other apparent ground wires still okay along the same path. This tuner box has its own power supply and a hidden fan that often runs when the set's in standby.(Don't think I damaged this copper link, but ~2001 a local Philips-service tech changed two nearby boards to fix a poor-sync problem.) Thanks for any advice. (Having CRT coolant fluids replaced soon, so getting into service mode for possible grayscale tweaking becomes more important.) -- John
 

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The cable output is just RF and should not hurt an antenna input. People do it all the time when the plug their cable into their TV with no box. I don't know if it will help your problem, but plugging cable into an antenna port should not hurt anything.
 

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Discussion Starter · #3 ·
Shifted the splitter input for the analog NTSC tuner into the DTV antenna jack. No difference, just an momentary "ATSC" logo with no menu access, which also appears with no input. (As mentioned earlier, of course there's no ATSC signal over the cable, only QAM/analog-NTSC.) Forgot to mention originally, the NTSC tuner operation with menus, setup, etc. works normally with the cable splitter input. -- John
 

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John,

I am not sure exactly what your current problem is.

Is it that with an antenna connected to your TVs digital tuner whcih only supports OTA digital broadcasts and not QAM that you no longer are able to receive any local channels?
 

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Discussion Starter · #5 ·
^^^Basically, yes, although I only watch via component inputs from cable TV these days. Rarely ever used OTA. Problem is I can't enter HD service mode (sm) because I can't first display any ATSC-mode menus or enter the sm number code. Pressing DTV on my remote only briefly displays "ATSC," then a black screen with no menu or sm access. Formerly, before this malfunction, the set tuned--or tried to--the last OTA HD channel watched and let me access HD menus or SM. SM access, not possible or that important for ~2years, may be much more important after an upcoming CRT coolant change. Troubleshooting suggestions welcome from all. -- John

EDIT: Digging further with my service CDROM, found I could enter service mode for NTSC. The service code number for HD differs by one digit, but I didn't try that because exiting SM improperly can screw up factory settings. But the CDROM says I can enter HD service mode while in NTSC mode. So, to prevent a mishap, guess I'll leave any tinkering to the service person changing the CRT coolant. The lack of OTA H/DTV tuning, since I don't use OTA anymore, may not be a problem then for coolant replacement and possible SM touchups.


Edit 2: Viisited andrewselectronics.com, now handling Philips parts, and see they'll sell me an ATSC tuning module for a mere $4758.14.
 
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