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Submitted By |
Kevin
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Date Posted |
6/27/2003 10:56:47 PM |
Title |
SONY KP-41T25 Projection TV - Erroneous video on screen. |
Message |
| On power-up, the video sometimes appears to be larger than the screen, sometimes is smaller than the screen, sometimes shows nothing. The red standby/timer LED on the power button often blinks....and then the TV simply turns off. Any idea where to start??
Thanks,
Kevin |
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Submitted By |
Stephen
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Date Posted |
6/28/2003 12:13:44 AM |
Title |
RE: SONY KP-41T25 Projection TV - Erroneous video on screen. |
Message |
| sounds like you have a prob in the power supply which is going over voltage. You can start by replacing all small electros in the power supply but after that a circuit will be required. |
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Submitted By |
Kevin
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Date Posted |
7/15/2003 1:42:20 PM |
Title |
RE: SONY KP-41T25 Projection TV - Erroneous video on screen. |
Message |
| I measured only 160V out of the 200V source from the transformer to the CRTs. I did find a shorted cap at the other secondary of the transformer output (heater regulator circuit -H+/H-) but this should not affect the other transformer output. Any other ideas? |
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Submitted By |
GC
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Date Posted |
9/16/2003 9:17:07 PM |
Title |
SONY KP-41T25 Projection TV - intermittent video "pops" |
Message |
| The blue gun and power supply were replaced on this unit to correct other problems, but the video now sometimes "pops" blank for a split second and resets. This happens only at 5-15 minute intervals. The audio is not affected. Everything else is fine with the set. What could be the problem here? |
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Submitted By |
Kevin
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Date Posted |
9/18/2003 6:02:11 PM |
Title |
SOLVED! RE: SONY KP-41T25 Projection TV - Erroneous video on screen. |
Message |
| Your problem is either IK blanking....or Vertical blanking. You need schematics.....and knowledge of the CRT protection circuits. Good luck!
BTW....I solved MY problem with the low Video Amp voltage and Filament Heater voltages. The 7.5V reference for the HV regulation cicuit was only 0.5V. It was an open 18K chip resistor at the output of the +135V (B+) divider. Replaced that baby...and watch all the voltages regulate to nominal. |
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Submitted By |
Kevin
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Date Posted |
9/22/2003 1:36:39 PM |
Title |
SOLVED RE: SONY KP-41T25 Projection TV - Erroneous video on screen. |
Message |
| Note that the previous "solved " post I placed ONLY repaired a secondary fault found in the power section of the unit. The HV Block was also replaced due to arcing, and was not specified earlier.
The original screen symptoms were actually caused by a faulty IC301 "Jungle IC". The symptoms were observed as follows:
On power-up, the screen comes up randomly, sometimes appears to be larger (vert. & horiz.)than the screen, sometimes is smaller vertically than the screen, sometimes 2 lines each for RGB, sometimes a small screen (Not PIP), and sometimes shows nothing. The red standby/timer LED on the power button blinks 1/sec.
It is likely that a faulty HV Block....caused the failure to both the HV regulation circuit and the "Jungle IC". The "Jungle IC" is an extremely sensitive device.
The vertical and pincushion outputs of the "Jungle IC" were not correct. Replacing the IC fixed the problem. Ordered it from MCM for $29. Make sure it is ORIGINAL SONY....and in original SONY factory-sealed bag. |
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Submitted By |
jim
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Date Posted |
1/24/2004 10:31:52 PM |
Title |
RE: SONY KP-41T25 Projection TV - red and blue on screen. |
Message |
| the screen has red and blue outline of picture it looks like it has a 3-d effect. |
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Submitted By |
wayne
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Date Posted |
6/2/2004 7:51:38 AM |
Title |
RE: SONY KP-46s25 no power |
Message |
sony kp - 46s25 when plugged in there are two clicks , the red standby led flashes and goes out when power button is pressed , set doesn't power up.two transistors[Q 601 and Q602 ] in the power supply were replaced also R607 but nothing happens, any suggestions? |
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