Screen has rolling rectangles from bottom left to top right? Ideas?

[gorfcadet]

I have three 7800s. One that is unmodded, one that has an av mod running into an internal hdmi adapter, and one that has the longhorn av mod. The longhorn av modded system has very obvious rolling bars going up the screen from bottom left to the top right. Any ideas what causes this? Is it an easy fix?

Any recommendations for a mod or repair service? Id like to get this one fixed to use as my workhorse for the XM and other projects.

 

[+Trebor]

I have three 7800s. One that is unmodded, one that has an av mod running into an internal hdmi adapter, and one that has the longhorn av mod. The longhorn av modded system has very obvious rolling bars going up the screen from bottom left to the top right. Any ideas what causes this? Is it an easy fix?

Any recommendations for a mod or repair service? Id like to get this one fixed to use as my workhorse for the XM and other projects.

 

80128934-20E9-4F3C-8240-6A53EE8C8F02.jpeg

 

Seems likely to be the typical TIA video interference that may be received at times. There's a previous thread on the issue.

 

I receive the same results if I do not engage the 'TIA 9' kill switch I opted to have installed with the video mod. The short and sweet of it is contained in this post. If interested in something more in-depth, see this page. The aforementioned thread provides a DYI on the 'TIA 9' kill switch installation.

 

The channel selector switch serves as the 'TIA 9' kill switch on my system. It works perfectly. The only thing to remember is to flip it the other way for 2600 mode, or else VCS games may appear incorrectly; it is at least partially, if not solely, dependent on what resistor value is utilized.

[gorfcadet]

Thanks! I was worried my system was about to die. Anyone around these days that does an alternate mod?

[+-^CrossBow^-]

The UAV is the absolute best way to go on the 7800 these days. Excellent s-video results and nice composite as well without the need to remove any components or install kill switches to turn off the TIA color burst signal.

 

I used to have a LHE mod in my 7800...never was happy with it and now that I finally got the UAV installed, I'm sold on the UAV for life. But yes in a nutshell you need a switch installed (Hate using the channel select switch because it is a PITA to get two and actually switch it). Use to have a monetary push button switch installed on mine, but now I have it on my Genesis to kill the sub-carrier video signal that causes interference with RGB and my HDretrovision cables.

[gorfcadet]

So best option is to remove the longhorn for the uav? Who is my best choice to get the operation done?

[+-^CrossBow^-]

Well, you can do that, or either install a switch or have someone setup the switch to turn off the TIA colorburst signal that causes this. As I said, I was never happy with my LHE install. It looked great on actual CRTs, but had horrible color bleeding on both composite and s-video on my LCD HDTVs that I used it with. That is why I'm such a believer of the UAV.

 

I can do the UAV insall, but you would have to wait until i got more UAVs in stock from Bryan before I could commit to it. If you didn't mind waiting, I'm more than happy to offer and either have you wait until i have one in for you, or be willing to have me hold it until then? Up to you and can PM me for details.