CurtPalme.com Home Theater Forum

**Curt Palme** · Posted: Mon Mar 23, 2009 5:37 pm Post subject: Sony G90 flickering dark to light

I've seen this before, it's a menu setting, something to do with the sync, but not having a G90 here right now in working shape, I can't check it.

I've had this on two G90s that I've had here in the past, that I've fed RGBs signals to. The picture will go from say a brightness level of 10 to one of 90, the pix can jump and flicker as well. What menu setting gets rid of this? I remember the first time I saw this, I changed every board in the set, only to solve the problem via this menu setting.

I could be wrong, but I think it was some setting that I had to take out of 'auto' mode to solve this.

Thanks!
Curt

Zebu Fellenz · Joined: 21 Dec 2006 Posts: 2548 Location: Phelps, New York

On the G70 there is a clamp setting that can cause things sort of like this. Possibly it is the same/similar setting on the G90?

Drew Packard · Joined: 12 Mar 2006 Posts: 40 Location: Monroe, Washington

Hey Curt,

The clamp needs to be changed to: "H/C"

I saw this many years ago when a mag reviewed the G90 with Faroudja's then new DVP 5000. Did the same thing to them....
They thought it was an incompatability and Faroudja came back with this...
Drew

Clarence · Joined: 08 Mar 2006 Posts: 3051 Location: Northern Virginia

SERVICE MENU... INPUT SETTING... CLAMP.
change CLAMP from AUTO to HP

**Curt Palme** · Posted: Mon Mar 23, 2009 11:12 pm Post subject:

Thanks guys, I've linked the customer to that thread, that's exactly what I was looking for.

sergio leone jr · Joined: 14 Aug 2007 Posts: 6 Location: Finland

Just wondering why my G90 always change clamp from H/C back to auto? I've tryed to save that setting also in deep memory. PJ is in standby mode. I read somewhere that this problem is fixed in last software. So is this software problem or something else?

Drew Packard · Joined: 12 Mar 2006 Posts: 40 Location: Monroe, Washington

Sergio,

Funny, that review in SGHT...they had the same problem(not saving the H/C setting). I remember them calling it a nuisance, and the only fault they could find with a G90 Smile

Drew

sergio leone jr · Joined: 14 Aug 2007 Posts: 6 Location: Finland

It was in Sony technical bulletin 1999-135R:

"Previously, when clamp setting value was changed in the Clamp setting mode ("INPUT SETTING" menu) and memorized, the value was saved; but when H/C was performed, the value reverted to the auto setting when the input signal was changed or the channel was switched over. This has been corrected. Now when the clamp setting is in H/C, if input signal is changed, the clamp setting does not revert to the auto setting."

(Firmware 1.11)

Drew Packard · Joined: 12 Mar 2006 Posts: 40 Location: Monroe, Washington

Good info...I know on my G70(early f/w) I don't have this problem. I set it to H/C(where it stays) and everything is fine for all inputs.
Drew

Mark_A_W · Posted: Tue Mar 24, 2009 5:51 am Post subject:

I've only played with a G90 once, and I ran straight into the clamping issue. They are finicky.

rrridenour · Joined: 24 Mar 2009 Posts: 1 Location: Colorado Springs, CO

I am the tech that is working on this specific G90 and I tried the clamping but it kept reverting to auto. I'm 95% sure I tried using the memory button to save it as well but I may have missed that. Once the change has been made, is pressing the memory button all that is required to make the change permanent?

RRR

**Curt Palme** · Posted: Wed Mar 25, 2009 12:45 am Post subject:

Yes, but it is mandatory to hit the 'store/save/memory button before you exit the service mode, or turn the set off.

CIR Engineering · Posted: Sun Mar 29, 2009 7:24 pm Post subject: Re: clamping