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Beovision 5102

 
Mikey66
(@mikey66)
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Posts: 189

My  little 5102 has a convergence error. The top horizontal blue is out, this being a 30AX tube set I thought was a little odd.

bo1

I tried adjusting the (tolerance)pot near the scan coils plug to no avail - made things worse.

bo2

The next thing was to try swapping the scan coils with my similar B&O 7702 , lo and behold the convergence error then appeared on the 7702 and my 5102 had perfect convergence.

I have manually degaussed the 5102 to no effect.

Other than trying to source a replacement 30AX yoke do any forum members have a possible solution. I did test the diodes but being in situ they gave confusing readings.

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Topic starter Posted : 05/09/2018 5:36 pm
malcscott
(@malcscott)
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Are there any rubber wedges come adrift?

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Posted : 05/09/2018 6:14 pm
Mikey66
(@mikey66)
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No Malc, it's all secure and the yoke is pushed fully forward and sitting on the bosses on the tube bowl

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Topic starter Posted : 05/09/2018 6:22 pm
PYE625
(@pye625)
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I guess the obvious check for dry joints and poor connections has proved fruitless?  ?

To understand the black art of electronics is to understand witchcraft.
Andrew.

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Posted : 05/09/2018 7:05 pm
Mikey66
(@mikey66)
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I can't see any bad joints. I'm thinking of releasing the PCB and checking the diodes properly. The only thing that puts me off is the PCB is part glued / potted along its bottom edge.

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Topic starter Posted : 05/09/2018 8:15 pm
malcscott
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You need a set of coils to try.

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Posted : 06/09/2018 12:14 am
Mikey66
(@mikey66)
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I've already done that - see first post-  Looks like I'm going to have to take a scalpel to the goo around the PCB and test the components there properly

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Topic starter Posted : 06/09/2018 7:11 am
PYE625
(@pye625)
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It sounds like an open circuit somewhere, could be a diode or a poor joint under the PCB or even on one of the lugs. I would think if a short, then the set would protest more loudly ?  Hmmm  an odd one.   ?

But a poor solder joint would probably give intermittent failure....this is permanent?

To understand the black art of electronics is to understand witchcraft.
Andrew.

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Posted : 06/09/2018 9:45 am
malcscott
(@malcscott)
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Could be gun alignment, try scan coils on another crt. It may have been like that from new, Malc.

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Posted : 06/09/2018 10:19 am
crustytv
(@crustytv)
Vrat Founder Admin
Posts: 10651

A little crossed wires going on here, Mike has already explained in his first post and then again two posts back, he has done this. The fault moved to the other set and the fault cleared in the original.  ?

Posted By: Mikey66

The next thing was to try swapping the scan coils with my similar B&O 7702 , lo and behold the convergence error then appeared on the 7702 and my 5102 had perfect convergence.

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Posted : 06/09/2018 10:26 am