CurtPalme.com Home Theater Forum

[JustGreg]

Hey Guys,
That's it...I'm raising the white flag because I've done all I know what to do to fix this. See graphic
I posted this crude EtchaSketch (sp?) before and worked through all the replies but still no joy.

I've swapped:
HDM
FCM
ALL the heatsink boards
CLM
VIM
Both power supplies
Swapped in an untouched stock 1100 chipped nb into all three (I only have one spare nb)
Moved the pj in case an overhead gas pipe was causing the problem
It isn't the position of the pj as it's at the tube face(s) although I've measured and refined the pj placement down to +/- .25".

...and I reinitialized in between each test change so as not to skew the results.

I've cleaned, reseated, reset, reinitialized, rubbed the belly of a Buddah...WTF OVER!?

One of the suggestions was to try different deflection yokes, which I haven't done yet because it just doesn't add up that three new tubes from two different people would produce the same identical effect across all three tubes. No...It has to be something I'm missing but for the life of me I can't see what that would be.

I can adjust it out but I'd rather find out WTH is causing it. I can't go on with the setup until I figure this out.

*sigh*

[cmjohnson]

Hmmm...vertical deflection amp, maybe? Got a spare to try?


Wait...you already said, all the heatsink boards. That'd be one of them.

Can you correct to a proper pattern with any available amount of correction?


Here's something to try: Reverse the horizontal scan by inverting the HDM connections. Of course you'll get mirror images, but does the shape of the raster stay the same or does it also become mirror imaged?





CJ

[Sparky015]

Wow, you've effectively swapped every single board. The only thing I can think of is a mis-aligned deflection coil. Maybe your PJ is driving the tubes a bit differently and you need to go in and do a complete re-alignment of magnetics, not just focus CPC and ASTIG. Even then, I would expect it to be rotated on the tube face, not skewed. Have you picked off the glue and tried rotating the deflection yokes?

How bad do you have to drive the electronics to correct it?

[Nashou66]

I do not think its the coils since he has three different tubes from two different people as well. i have been sitting here thinking hard and can come up with anything.

Greg did you not say once that you had a problem with the connector on the mother board for the HDM? A trace was lifeted or something?

I wonder if that could be the issue?

[CZ Eddie]

Are you using unistrut? Is it the demagnetized version? Any kind of weird metals or electric field or mageticy type stuff nearby? Speaker magnet?

If you drop the PJ & move to another room, does it still do this?

[Sparky015]

[garyfritz]

I don't think there is, unless you find an aluminum version. Any steel unistrut can *become* magnetized. You can run it through a degausser, or take the low-tech approach and whack it with a hammer a few times (which actually can demagnetize it!), but I don't think you can *buy* demagnetized strut. Unless someone here on the forum has gotten entrepreneurial...

[cmjohnson]

Stainless steel, non-magnetic strut IS available.

I've also seen it made of fiberglas.


CJ

[garyfritz]

True, I didn't think of stainless. But in any event I would think it would take a pretty seriously magnetized strut to have any significant impact on convergence. The convergence/etc circuits have a lot of leeway to adjust for the Earth's magnetic field, local magnetic fields from electrical wiring, etc. They should be able to adjust for any reasonable level of magnetized strut too. I seriously doubt Greg's problem is caused by his strut.

And if I understand right, Greg has the same amount of distortion on all 3 tubes. That would argue against magnetized struts, since the magnetic field would impact the closest tube more than the farthest tube.

[Nashou66]

And Greg has the PJ dropped pretty far down into the room from the ceiling. I was going to suggest a stray Magnetic field from AC wires or a vent fan etc , but its too far away from the ceiling . I still say its something electrical in the set . A bad HDM to Mother board connector might be the cause here. he mentioned it was slightly damaged before in another thread i think or in a PM to me I have to look for it.

Athanasios

[dvh99]

ribbon cables perhaps swap the astig with vdm or convergence.
otherwise it must be something on the main board since you ruled everything out.

essayer

[JustGreg]

Happy Independence Day everyone. I pray that if you have a friend or loved one serving they remain safe until they can come home. (All but 50K troops by end of summer?)

Thanks for the replies. This is frustrating to say the least but logic dictates that whatever it is, I somehow caused it.

So far the most likely culprit would be the mild steel UniStrut mount I made. I welded the mechanically cut pieces of the frame and most likely created a magnet field in the process. There's also a 1" gas line above the pj ~3-4" away that isn't helping matters.

Nash, the solder pad that was lifted is at the resistors for the anamorphic mod. I backed that lifted pad up with a flywire on that particular board but the spare board did the same thing too.

I'm still not ruling out the need for mags realignment but dayum, what a coincidence that would be if that were the problem.

Enough screwing around...I'm going to lower it, bench it, and tear it down to the chassis. It won't see any altitude again until I'm positive it works fine in another room as suggested.

I'll scrounge up some stainless UniStrut at work and build another frame too and post back in a week or so when done with everything. Back to work tomorrow after two months off so I'll be a hurtin' unit for the first week.

Thanks and have a safe holiday.

[JustGreg]

[JustGreg]

[garyfritz]