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landok Guest
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Posted: Tue Aug 02, 2005 2:09 pm Post subject: Grundig ST-95-775/9PIP/TOP |
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Hello all..
I have problem..
I have sound, but no picture. I had this problem time and time again.. So after paying 200€ about five times for repairs, I decided to try it myself..
I replaced TEA 5101B ic, (that's what Grundig service did )but no luck.. Can anybody please give me advice how to fix that problem?
Thank you in advance.. |
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Al_Dodge_Bundy
Joined: 05 Apr 2005 Posts: 93 Location: Netherlands
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Posted: Wed Aug 03, 2005 7:45 am Post subject: |
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Do you still have high voltage on the tube? (static sound when turning on/off the screen)
And are the tube's "heaters" glowing? (just turn of the lights in your room and check the back (neck) of the tube)
Grtz Mark |
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Guest
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Posted: Wed Aug 03, 2005 12:26 pm Post subject: |
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Thank you for a quick answer Mark..
Yes heaters are working an I can feel and hear static when you switch the set on.. I can't hear static discharge when you switch it off tho.. (I don't remember I ever did hear it..)
But before I screw up more than I'd like to, I'd like to know if pin 11 of TEA 5401 goes to R 762 only, or does it connect to BR 12 as well. You see, that IC was replaced so many times that (almost) all copper traces are damaged. It would be great if I had schematics and print layout from picture tube printplate (29305-022.41)
I also see that focus capacitor C 07 is 580pF ( two 1500pF 6000v in serie) and from what I saw somewhere on the net should be 68pF 12.500v..
Bij voorbat dank.. Groetjes, Phil.. |
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Landok
Joined: 03 Aug 2005 Posts: 4 Location: Netherlands
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Posted: Wed Aug 03, 2005 12:52 pm Post subject: |
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Sorry Mark.. It was me.. _________________ You Might Be a Tubeneck if your wife says "Is that a tube in your pocket, or are you just glad to see me?" and it's a tube. |
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Al_Dodge_Bundy
Joined: 05 Apr 2005 Posts: 93 Location: Netherlands
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Posted: Tue Aug 09, 2005 9:26 am Post subject: |
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Ohh, I don't think I can help you with which pin's are connected to what parts. You could try to search for a diagram on this set.
The Chassis-Code is CUC5836.
Veel Succes
Mark |
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picasso
Joined: 01 Aug 2005 Posts: 9 Location: Belgium
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Posted: Fri Aug 12, 2005 3:49 pm Post subject: diagram |
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I have the crt panel-diagram.I can send it to you if you like.
PS : 1)also check the vertical deflection.You can simply do that by heyghten the G2-votage.The sreen must become grey now,with flyback lines.If you see nothing,replace frame Ic and/or check conections and solderings.
2)Concerning the crt panel : when you replace the tea5101,also replace R793 = 330 ohm (200V supply)
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Guest
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Posted: Fri Aug 12, 2005 5:55 pm Post subject: Re: diagram |
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picasso wrote: | I have the crt panel-diagram.I can send it to you if you like.
PS : 1)also check the vertical deflection.You can simply do that by heyghten the G2-votage.The sreen must become grey now,with flyback lines.If you see nothing,replace frame Ic and/or check conections and solderings.
2)Concerning the crt panel : when you replace the tea5101,also replace R793 = 330 ohm (200V supply)
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Man you're great.. Yes please.. If you can send me that diagram, It'll be great.. Thank you for your valuable tips.. I see that R793 is a 220ohm resistor. Do you think that that might be a reason for TEA5101 constant failure? I mean they replaced it like five times already. Last time guy from service build diode protection circuit reasuring me that now nothing could happen to IC. |
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picasso
Joined: 01 Aug 2005 Posts: 9 Location: Belgium
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Posted: Fri Aug 12, 2005 11:00 pm Post subject: diagram |
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? email adress
A broken R793 is a result of a failure of tea5101.
Normally a modification wit 3 bav21, like Guy did, will fix the problem.
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Landok
Joined: 03 Aug 2005 Posts: 4 Location: Netherlands
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Posted: Sat Aug 13, 2005 7:25 am Post subject: Re: diagram |
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picasso wrote: | ? email adress
A broken R793 is a result of a failure of tea5101.
Normally a modification wit 3 bav21, like Guy did, will fix the problem.
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PM sent.. R793 isn't broken.. It's just not 330 ohm but 220 ohm that was never replaced.. _________________ You Might Be a Tubeneck if your wife says "Is that a tube in your pocket, or are you just glad to see me?" and it's a tube. |
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