CurtPalme.com Home Theater Forum

[jaredjaric]

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HI ,

Can anybody please advice me on this issue.

Before the whole focus issue, the projector suffered a shutdown, and a red led lit up on the EHT board.

After swapping out the quad and eht, the splitter was found to be the culprit.

But after replacing the splitter , it started to had issues with the image,
and i found on the vertical board the red led lighting up intermittently.
I was able to swap in a good vertical board and then the replaced splitter caused another shutdown.
Had to put in another good splitter, and now the image is intermittently slightly going in and out of focus,
as if there is someone moving the magnetic yokes back and forth millimeter by millimeter.

And so i had to swap focus boards,
After swapping focus board ,
the modulating still remained, and the focus was still very good
( midpoint foucs on all CRts were at 21).

i then had to swap in a whole convergence tray, this included the focus board, controller boards , astig board etc.

This is when the 909 really can not focus well anymore, i ramped up the midpoint focus adjustment both ways,
it was at first was tolerable , but kept getting blurrier as the modulating also kept going.


Only the neck boards and coils i have not swapped.

[r.bauer]

EHT problems/fluctuations will lead to changes in focus. EHT voltage can be measured, but you can do it only safe when you have the proper probe.

[jaredjaric]

Hi,

Yes , i checked the coaxial cable on the splitter , it measured 34v dc.


Thanks for the input.

[r.bauer]

Maybe check the high voltage also?

[jaredjaric]

[jaredjaric]

Here is the picture of my out of focus 909,

It is also shaky or modulating,

real HV issues that i can not find.

[jaredjaric]

here is another shot

[Curt Palme]

Do the electronic focus controls (especially the middle zone) have any effect on all 3 tubes?

[Curt Palme]

Do the electronic focus controls (especially the middle zone) have any effect on all 3 tubes?

[jaredjaric]

yes, using the menu to access midpoint focusing ,

it helps but maxed out at 99, still very soft and blurry.
original focus for all three guns based on throw distance was 19 to 23 only.

i disconnected the focus leads from focus coils to board,
it is just a bit more blurry ,it is showing that the focusing electronic circuit is not helping by much.

[jaredjaric]

also swapped out three controller boards, still can not trace the issue.

[Hulio]

I know it sounds stupid, but have you checked the optical focus too ? Sometimes, if the focus knobs on the lenses are nor firmly tighten, they can drift....

[jaredjaric]

[jaredjaric]

is there such a thing as a failing coil on all three ?

[Hulio]

Nah, a focus coil can fail indeed, but the odds that all three are giving up at the same time, are close to 0.
Is a hard one, given the fact that you swapped every board...Could be a burned component or bad contact on the mainboard ??

[km987654]

A bad splitter will cause this. Can you hear any buzzing from the splitter. I see that you have changed that and then your focus problems began. They go bad internally and arc and focus is uncontrollable.

[jaredjaric]

[jaredjaric]

the line up :

the second one is up for an operation

[jaredjaric]

am doing it all for this.

[ElTopo]

or for this

[jaredjaric]

for Furs and wrinkles??