CurtPalme.com Home Theater Forum

[KrisRoberts]

This week I started seeing a pattern of lines flashing on the screen occasionally while watching movies.

The first few times I noticed it there were horizontal bands of them that would appear and disappear quickly.

Since then it seems to have gotten progressively worse, and now it is clear that its a whole rectangle of lines. The rectangle pattern flashes for a bit and then goes away. Sometimes only for a second or two, and sometimes for much longer.

It happens regardless of which input is used, and does not matter if there is an external signal or not. I have removed my moome card and put the projector on Input-A with no signal attached and it still shows up on the test patterns.

The lines disrupt video and the test patterns generated by the projector, but do not affect the menu text or text on the test patterns. It is interesting that the size of the rectangle corresponds to the area used to display text on the test patterns and that the lines precisely match the spacing of the test pattern grid.

Is it possibly a malfunction where whatever is used to display the on screen text is freaking out and showing these lines when it shouldn't be showing anything?
I did try toggling the "Status" option which suppresses some of the on screen text but that didnt change the behavior.


Full Resolution Image - 631KB

AVI Video (Right Click Link and Save) - 50MB
Ignore the ground loop line - thats just the sync between the projector and the camera.

[ecrabb]

I could be wrong, but I believe somebody just posted about this exact problem with their G90 in the last 4-6 weeks or so.

SC

[KrisRoberts]

Alan did reply to the sister thread on AVS and pointed me to the previous thread there:
http://www.avsforum.com/avs-vb/showthread.php?t=1232737&highlight=g90

But searching this forum I dont find a similar thread - was there one here too?

[ecrabb]

I looked for a few minutes and didn't find anything... I just know I remember seeing photos that looked exactly like what you posted. Could have been a couple of months ago. If memory serves, Curt thought he could fix it and told the poster to send the board(s). I got the sense it was something reasonably easy to fix. Might want to just PM Curt.

SC

[Nashou66]

Alan Winslow had the same issue. I think curt has his boards or he was going to send them to curt. Not sure.

Athanasios

[CIR Engineering]

Yup Alan has the same problem and I don't know if the issues has been figured out yet or not.

Curt? Do you have Alan's board now?

I'll shoot Alan an email and ask him to pop in here.

craigr

[Alan Winslow]

Curt is working on my board which he has. In last contact with him, Wednesday he got in the suspect parts he feels should resolve the issue.
I was surprised to see the exact issue I had being no one had seen it before. You can almost overlay the the pics he posted to mine and it is in the same place and size.
We'll keep the thread posted and I have been in direct contact with Kris.

[KrisRoberts]

Curt's post on the AVS thread sounds encouraging. Hopefully his fix on Alan's board checks out!

These forums are great.

[Curt Palme]

Nope, still bad. I think it's lessened, but it's still there. Time to dig out the scope and narrow it down...

[Curt Palme]

Nope, still bad. I think it's lessened, but it's still there. Time to dig out the scope and narrow it down...

[perisoft]

[KrisRoberts]

I was able to pick up a second G90 for parts this week.
Its a high hour machine and the tubes are pretty worn, but it seems to work fine and I wasnt able to see any of the issues I've seen in other G90s.

Once I get it home I'll swap the YA boards and see if that resolves the issue at hand.

A while ago in another thread on AVS it was suggested that the YA and YB boards were somehow matched and should be kept together. Does anyone know if that is indeed the case?
http://www.avsforum.com/avs-vb/showt...d#post12821699

Since I have both I'll probably keep them together just to be on the safe side, but I'm wondering if its true...

[CIR Engineering]

You can swap YA boards in a G90 no problem. However, the FW versions must be the same between the two YA boards, you must swap Dallas chips, and neither board can be in simulation mode (though I have never seen a G90 that has been in simulation mode unless I put it there).

BA boards can not be swapped between projectors without recalibration of the projector and possible the BA board drive trimmers.

craigr

[CIR Engineering]

I talked to Curt today and he thinks he has figured out the problem with your two boards. However, the part is not available anymore.

I do have one of said parts here and could fix one of the YA boards with it... assuming this is the problem and nothing goes wrong during the repair.

craigr

[macgyver655]

[stefuel]

[KrisRoberts]

Thats not good news, but it does make me feel better about the gamble I took buying the other projector.

Hopefully Alan's board can be repaired. If its possible I'll be interested in having my bad one fixed, but obviously only after a solution has been found and Alan is up and running again.

[Nashou66]

I think the price of my G90 just went up !



Athanasios

[HaydnG90]

Interesting, so IC421 isn't the only unobtanium chip.

[Curt Palme]

The stupid thing is, NEC makes this other chip, but no one has it.

[Curt Palme]

The stupid thing is, NEC makes this other chip, but no one has it.

[macgyver655]