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Thank you very much kf4rca for your technical advice (yesterday and today).
The trouble seems to be in the heads/preamplifier because one RF chroma packet is missing. So I will not be dealing with the filters. But it is good to know. Also about the capacitors behaving badly while cold.
Also thanks a lot to baursam and fsjonsey for replying. I am relatively new to VK and will welcome any colleague visiting Cuba.
I will let you know f I need some part brought to Cuba, paying for it of course!!!
Small packages can be also sent by mail. But I havenīt get to that point yet.
I downloaded the BVW-75P service manuals from a Hungarian site called elektrotanya. I strongly recommend it to all of you, and will start another thread so many VKers become aware of it. Absolutely free (thatīs a good thing for someone without a credit card account, yes, that still happens in this world).
At elektrotanya there are mainly European service manuals, of course. But the second volume (the one with the schematics) happened to be NTSC.
I know my machine is a 70 and not a 75, but about 80% of the boards are shared among these two machines, and the ones I need are in the 75īs manual. So, later today I am going to dig with my scope, maybe swapping the identical RF preamplifier boards among Y and C channels, and so will know if the trouble is in the heads or in the electronics.
If the heads are damaged it will be more difficult, but maybe I can find them in Cuba. I have the eccentricity jig (the same used for the UMatics). After that the electronic alignment will be a slow process, but with help from Cuban TV (they have the alignment tapes, extender boards and so on) it can be done.
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