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SouSa
Joined: 21 Oct 2007
Posts: 6
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 Posted: Sun Oct 21, 2007 4:23 am Post subject: Grundig TV CUC 3400 no image and short circuit |
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hi, i have a grundig tv CUC 3400, and i turn it on it works all, sound and at the begging about 3 seconds image, but then the image dissapear and stay all the time black i can't see nothing 
other thing, when i'm measuring the tv with multimeter in the BU508 when i measure the emissor it gives a short circuit... a spark and tv seems to go down just for one second....
is this normal ??? hope you can help me i'm new here but is my job ( electronic ) and i hope i can help other people.
thanks  |
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SouSa
Joined: 21 Oct 2007
Posts: 6
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| Posted: Mon Oct 22, 2007 3:08 am Post subject: |
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i measure all tensions, and everthing is good
the tv start up with normally, and image comes but only two seconds, then go down and screen are all black, but have sound and tv work's normally.... tensions are all good in that mode....
in the start up of television i noted a blue stripes in screen just before image comes....
what do you think it is???
i already substitute some capacitors, but don't work anyway....
do you think maybe can be tuner ??? or chip from crominance/luminance???
hope you can answer me
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vtech
Joined: 08 May 2006
Posts: 1264
Location: USA
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| Posted: Tue Oct 23, 2007 10:04 pm Post subject: |
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I am not familiar with the set, but sounds like somehow you are loosing the video. Since the voltages check ok. Suggest scoping the video path from the luma/chroma processor circuit/chip and see if you can find where it disappears. ofcourse need to have schematic or IC diagram
Good luck |
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SouSa
Joined: 21 Oct 2007
Posts: 6
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| Posted: Sat Oct 27, 2007 3:05 am Post subject: |
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| vtech wrote: | I am not familiar with the set, but sounds like somehow you are loosing the video. Since the voltages check ok. Suggest scoping the video path from the luma/chroma processor circuit/chip and see if you can find where it disappears. ofcourse need to have schematic or IC diagram
Good luck |
hi, thanks for you answer, i already replace the chip from chroma and still don't work...
waht do you think it could be ??? |
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SouSa
Joined: 21 Oct 2007
Posts: 6
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| Posted: Sun Oct 28, 2007 6:43 pm Post subject: |
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| anyone?? |
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carl french
Joined: 27 Oct 2007
Posts: 7
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| Posted: Sun Oct 28, 2007 7:21 pm Post subject: |
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| do you see pic or line across screen when switched on |
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SouSa
Joined: 21 Oct 2007
Posts: 6
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| Posted: Mon Nov 12, 2007 12:31 am Post subject: |
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i see pic about 3 seconds, then stay all black...
when i turn on i see lines across the screen too, but only when turn on, after 3 seconds stay black...
what do you think it could be ??
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SouSa
Joined: 21 Oct 2007
Posts: 6
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| Posted: Tue Nov 13, 2007 8:53 pm Post subject: |
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| anybody? |
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Guest
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| Posted: Sun Dec 16, 2007 6:24 pm Post subject: |
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| This tv is well known for bad solder joints. Re-solder the line output and power supply area first, no matter what you do next. |
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Pilsener
Joined: 18 Dec 2007
Posts: 8
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| Posted: Tue Dec 18, 2007 9:46 pm Post subject: |
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Here's a little trick:
Turn up Ug2. Then you can see if you get a colored background, probably with flyback stripes, thus determing if the h/v deflection is ok. This should be the first thing to check in this case.
Another thing on the CUC3400 is the CRT-socket. I have experienced several bad sockets. This can cause loss of Ug2 to the CRT, causing black picture.
These models also had some problems with some ic's on the video module. One of them was called TDA6600 (I think). |
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