Wells Gardner d2900 pulsing screen .. caps ?

Retroman839

Retroman839

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Yeh this monitor is kind of pulsing. In the top left & bottom left corner
See here
WG d2900 screen pulsing caps ?

Plan is to change these 4 large caps
These 2
IMG_8408.jpegIMG_8409.jpeg
2x 200v 390 uf

Being a digital chassis it’s litterd with ic ..

Anyone have any pointers as to why screen is pulsing ?thanx
 
Retroman839

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gunblade said:
degauss stuck on maybe, disconnect degauss coil and see if it clears
Click to expand...
Yeh thanks grant I think you are correct
Even though I have not yet checked ..

Makes sence as I hade some gausing discolaration as well ..

Só this would mean i have constant current flowing in to The coil ?

Faulty PTC Thermistor ?
 
Retroman839

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gunblade said:
it would switch 12v to the relay, can you here the relay click when you press degauss button?
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This type Controll pcb is without degause button unfortuanlty ..

I might have one somewhere ..
Maybe that might explain of I have the incorrect Controll pcb hmmm

Only got
Up down mode and select on the control pcb
 
Retroman839

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Degausing harness was the culprit thanks .
One problem goes
A new one comes



I have a lovely 15khz image on this ..
But Can’t fill screen on left side . The raster bars squeeze up and stop as shown on left side ..

On my SanwA 27z I can shift screen using pots on the chassi. H v position Pots on the chasis ..

Anything like that or
Os this caps / componant issue ?

this is a secomd d2900
The original has same issue
Squeezed in vertical ..

Pin cusion
Trapazoid
Had no effect ..

Also cannot locate a demag in either factory or normal menu

IMG_8454.jpeg
Had to sort these two legs on this transistor also nos chassis but old and i guess they were just chucked about heat sinks pulled the compomamts out with it..

But super sharp 15khz image
I can go super large with the image só not sure if this has been modded at factory for a 33” showcase or larger
IMG_8445.jpeg

You
Can see the screen reduction on leftIMG_8431.jpeg
 
tb2000

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That curling on the left is a vertical deflection problem. I think there's a few caps around the vertical deflection chip (STV8172 or TDA8172) that go bad. If it's a NOS chassis they shouldn't be (maybe some are a bit dry), but it's worth changing them anyway. I think it's only about 3 or 4 caps - I sorted the same problem for an op some years ago, it luckily in my case it was just a few caps. Have a look here to find the same problem and solution.
 
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Retroman839

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tb2000 said:
That curling on the left is a vertical deflection problem. I think there's a few caps around the vertical deflection chip (STV8172 or TDA8172) that go bad. If it's a NOS chassis they shouldn't be (maybe some are a bit dry), but it's worth changing them anyway. I think it's only about 3 or 4 caps - I sorted the same problem for an op some years ago, it luckily in my case it was just a few caps. Have a look here to find the same problem and solution.
Click to expand...
Hey man cheers

Yeh the caps In the vert deflection crossed my
Mind ..
I do recall reading this issue is normally caps ..
I have same issue going on on a SanwA 27c actually só if this works i can go on to do that one as well..
 
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