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Old 13th Sep 2023, 1:49 pm   #1
xrodney
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Default Grundig A8400 F3026 CUC720

HI

I have the above mentioned TV. I tried to switch in on, front channel display works but TV does not turn on. After a few minutes I heard a pop and smoke.

are there any service kits readily available for these monitors?
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Old 13th Sep 2023, 2:57 pm   #2
Welsh Anorak
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Default Re: Grundig A8400 F3026 CUC720

I'm afraid with TVs like this you have to rely on old fashioned fault finding - no such thing as service kits for them.

Looks like a capacitor has failed in your second picture. Remove it and have a look and see what's happened. A spare shouldn't be too hard to come by. However it might simply be a bad connection on the blue coil - hard to tell.
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Old 13th Sep 2023, 3:02 pm   #3
German Dalek
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Default Re: Grundig A8400 F3026 CUC720

Hi,

At first you have to find the right schematic.
I see a lot of corrosion and rust.

It should have been better, to dry the set out, inside a car which is placed in the sun, has to be no problem on Malta.
I should do that for about a week, then I should switch it in again.

Because of the moisture you have to count on a number of issues.

Are you able to measure?

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German Dalek
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Old 13th Sep 2023, 4:06 pm   #4
Maarten
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Default Re: Grundig A8400 F3026 CUC720

The pop and smoke might be the mains suppressor capacitor which will be a Wima or Rifa paper capacitor. It will need to be removed and replaced even if it wasn't the problem this time.

The not fully turning on, might be the hifi relay.

Just two common problems, no guarantee, you might have to do a visual inspection and take measurements.

Edit: the blue capacitor in your second picture looks like a Wima paper capacitor.
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Old 13th Sep 2023, 4:48 pm   #5
Maarten
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Default Re: Grundig A8400 F3026 CUC720

The other blue capacitor to the right of the coil should be removed or replaced as well.
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Old 13th Sep 2023, 5:09 pm   #6
Nanozeugma
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Default Re: Grundig A8400 F3026 CUC720

From what I can determine from your image(s) one of the mains filter capacitors appears to have failed. They appear to be 3.3nF 400vac Y rated. Replace both and go from there.
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Old 14th Sep 2023, 8:16 am   #7
xrodney
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Default Re: Grundig A8400 F3026 CUC720

Thank you all for the input. yes those 2 capacitors seem to have failed. the schematics show they are 0.15uf 250v.

I will take the board out, inspect it and start from there.
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Old 14th Sep 2023, 9:03 pm   #8
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Default Re: Grundig A8400 F3026 CUC720

They can be replaced by 0.15u 275VAC (or higher) X2 rated capacitors. MKT or preferrably MKP, no paper types.
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