CurtPalme.com Home Theater Forum

[CasetheCorvetteman]

It is the keystone that makes the horizontal lines level from top to bottom, so if your picture is taller on the right and shorter on the left, you would use the sideshot keystone to correct that, and make the image the same physical height at the left and right extremes. It will almost certainly be just called Keystone, and will be split into horizontal and vertical.

Adjust that setting from one end of the scale to the other, and compare the amount of movement with the same setting on the blue tube, cause they should have pretty close to the same range ( wont always be exactly the same range unless you have every other setting on blue and red set exactly the same. )

[rambon]

[CasetheCorvetteman]

Youd have to be able to on the red and blue surely!!

[mc86]

Nope, the keystone control on ECPs (4xxx anyway) does both sides at once and all three colors simultaneously. Now there is a keystone module, but I seem to recall Curt telling me those boards don't fail. And even if a keystone board failed, I'm not sure it would fail like this...just a part of one tube's image. So, accepting convergence as not it since you swapped boards, let's see...

The pic looks more to me like top and bottom pincushion is out on the right side for the red tube. The waveform module generates the pincushion/bow info. From there, the deflection board needs to process the info pincushion/bow information correctly. So:

First, re-seat/clean contacts on BOTH the waveform module AND the piggyback board on the waveform board (it does pincushion stuff). Second, you might swap-in a different waveform module.
Finally, you might switch the red PDM board with another to troubleshoot there...a bad convergence amp on the PDM might explain why only red does this. I'm making this up, but in looking at the diagrams, seems remotely plausible.

OH, IF this is a keystone issue somehow and the keystone module is not to blame, the waveform module could again be the guilty party. The 4100 manual says the waveform module "also provides geometry correction waveform signals to the Keystone, Power Deflection and Bias modules." Similarly, the PDM also has a convergence amplifier which could be bad. In both cases, pincushion or keystone, the same components are in question.

OK, that's all I got!

Matt

[rambon]

Thank you all for the tips. I finally got it to work, I don't know what finally did it, but this is what I did. I had another case with another motherboard so I took everything apart and rebuild the projector to the other case. And just like that it was working again. I changed too many parts to know exactly what went wrong. But finally I am having a movie night.


Thank you guys!