Nice, I like this attitude best!Rodrik wrote: Back on interferences, I will try to fix this V3 GBS board following your inputs whatever time/skill it requires, it's more about the journey than about the result and/or costI like modding things.
This is how I got into my modding projects
![Smile :)](./images/smilies/icon_smile.gif)
When I got my first gen GBS-8220 (had to look hard for it!), I initially improved the Vcc stability as usual.
Removing C11 turned out to be very important.
The other tweaks (10uF and 22uF SMD caps) had the usual effect of smoothing out Vcc on the scope but not really making a difference in picture quality.
There was always that mild interference pattern, no matter which source / preset was active.
Suspecting the video driver chip, I turned to the ISL59833 datasheet: https://drive.google.com/drive/folders/ ... GFOMUFVdlE
Sure enough, it is an odd IC that generates noise as part of its operation. (These 2 things usually bite each other.)
If your remaining noise fits that description, then the fix is working on R58.
A small power bead slows down the current spikes the charge pump can generate. A reservoir capacitor should be used to deliver the current instead.
As for a replacement GBS, most designs are the same at the core.
The ones with yellow buttons, often with a "V3" or "V3.5" mark, appear to be the newest design.
They do require the 10 / 22uF caps and C11 removal but then deliver a great picture. They're also the cheapest versions currently available
![Smile :)](./images/smilies/icon_smile.gif)
The HDMI version is also very interesting, if your display accepts HDMI over DVI (I found the ratio of displays that support it vs no support is 50/50).
If it is supported, the HDMI version is more consistent when tuning for "best" picture quality / sharpest pixels.