V1.0 horizontal line on screen.

[facade]

Background. I got hold of a v1.0 (gpu fan model) with the intention of TSOP flashing it, but it wouldn't boot past the logo, and I diagnosed hard drive failure. The clock capacitor hadn't leaked when I removed it, and the Thompson DVD drive works, so I'm guessing the hard drive failed early and the Xbox was put away faulty.  Anyway I fitted an Aladdin (breaking a track fitting the rom disable )  Having fixed the track, fitted the rom disable to a different place and swapped the hard drive, it works!

 

However, there is a horizontal line (usually pinky coloured) that slowly moves up and down the lower third of the screen. The line was there before I fitted the Aladdin. Sometimes it disappears, sometimes it is very noticeable.

 

I tried removing the motherboard again and cleaning all the contact points to the screening can, including the fingers on the video socket.  The video lead is fine when connected to my other xbox (component video btw)

 

I'm hoping it is just a capacitor, but which one? They all look perfect even under a magnifying glass, no signs of leakage, splitting or bulging. I'm reluctant to just change loads of them, as

1) I'd fit eBay components, so they might be fakes and worse than what is in there at the moment

2) with the trouble breaking a track (my eyesight isn't what it used to be) I might cause more problems than I solve trying to change them.