Unwanted freeze frame during play back of DVD by Philips DVD-625 and various other

tiefbassuebertr · 09:52 AM

Unwanted alternating between moving images (normal function) and freeze frame (still image) by DVD625 - image about
http://srvimg08.aprod.hu/images_apro...esfehervar.jpg

By certain DVD's I observe sometimes an unwanted freeze frame and demolition of sound for 1-3 sec. After this "Play" function starts again and is normal for two until three minutes. Then occurs a new interrupt repeat with freeze frame on the screen.
This effect is only to observe by various DVD's, not by all. This effect occurs both at burned DVDs and pressed DVDs.
OTOH - by several but not all other models/brands this effect is to observe.
In the troubleshooting flow chart of this model this effect isn't mentioned.

How I can narrow the cause ?
Thank you for your advices.

Service Manual of this model you will find here for download:
Philips DVD 625 Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics
Download the Philips DVD-625 service manual for free - Hifi Manuals

Extreme_Boky · 3rd February 2012, 08:18 AM

It appears that DVD / CD mechanism has local RF amplifier (as part of the mechanism). The signal you want to check for pp value is labelled TP15, i.e. it is pin 96 on MT1336E.

Look for close to 4V pp RF signal here. Try different DVD or CD discs – each disc has different reflectivity. You have to make sure that with low reflectivity discs, this pp valu is at least around 3.5 V pp. If it is lower than that, adjust the lens output by turning the miniature trimpot located on the lens pick-up clockwise “just a bit”. Recheck with CRO and do not go above 4.2V pp with high reflectivity discs. Vcc is 5 volts, so 4.2V pp value should be ok. I am not familiar with MT1336E. Try to find its datasheet for exact maximum RF value at pin 96. (it could be even 4.5 V pp…)

Cheap mechanisms come pre-adjusted for “correct” lens output, but due to change in lens-to-disc geometry and “aging” this pre-set value drops after a year or so. Re-adjusting this lens output helps in 90% of the cases.

Boky

tiefbassuebertr · 3rd February 2012, 09:32 AM

thank you for this advices. I will check this next time.
Is it usual, that such effects by dvd player, which I have described, occurs when the rf level is too low (unlike cd player) ?

2nd February 2012, 09:49 AM	#1
tiefbassuebertr diyAudio Member Join Date: Jul 2005 Location: D-55629 Schwarzerden	Unwanted freeze frame during play back of DVD by Philips DVD-625 and various other Unwanted alternating between moving images (normal function) and freeze frame (still image) by DVD625 - image about http://srvimg08.aprod.hu/images_apro...esfehervar.jpg By certain DVD's I observe sometimes an unwanted freeze frame and demolition of sound for 1-3 sec. After this "Play" function starts again and is normal for two until three minutes. Then occurs a new interrupt repeat with freeze frame on the screen. This effect is only to observe by various DVD's, not by all. This effect occurs both at burned DVDs and pressed DVDs. OTOH - by several but not all other models/brands this effect is to observe. In the troubleshooting flow chart of this model this effect isn't mentioned. How I can narrow the cause ? Thank you for your advices. Service Manual of this model you will find here for download: Philips DVD 625 Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics Download the Philips DVD-625 service manual for free - Hifi Manuals Last edited by tiefbassuebertr; 2nd February 2012 at 09:52 AM.

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3rd February 2012, 08:18 AM	#2
Extreme_Boky diyAudio Member Join Date: Dec 2003 Location: Sydney	It appears that DVD / CD mechanism has local RF amplifier (as part of the mechanism). The signal you want to check for pp value is labelled TP15, i.e. it is pin 96 on MT1336E. Look for close to 4V pp RF signal here. Try different DVD or CD discs – each disc has different reflectivity. You have to make sure that with low reflectivity discs, this pp valu is at least around 3.5 V pp. If it is lower than that, adjust the lens output by turning the miniature trimpot located on the lens pick-up clockwise “just a bit”. Recheck with CRO and do not go above 4.2V pp with high reflectivity discs. Vcc is 5 volts, so 4.2V pp value should be ok. I am not familiar with MT1336E. Try to find its datasheet for exact maximum RF value at pin 96. (it could be even 4.5 V pp…) Cheap mechanisms come pre-adjusted for “correct” lens output, but due to change in lens-to-disc geometry and “aging” this pre-set value drops after a year or so. Re-adjusting this lens output helps in 90% of the cases. Boky

3rd February 2012, 09:32 AM	#3
tiefbassuebertr diyAudio Member Join Date: Jul 2005 Location: D-55629 Schwarzerden	thank you for this advices. I will check this next time. Is it usual, that such effects by dvd player, which I have described, occurs when the rf level is too low (unlike cd player) ?