Botched composite install on PAL heavy sixer?

[Cloaked Alien]

First of all I'm no wizard with the soldering iron, secondly I'd like to think I know my limits and thought I did a pretty decent job. Sadly it does not work and the composite mod is the deluxe variant bought from tfw8b probably around a year ago so the mod itself should be both compatible and of quality. Sound seems to work, but sounds a bit weird, but video is out of sync and only gives me weird lines on the CRT.

The machine was working fine over RF before so it's absolutely my own fault. Question is just what and how to fix it ?

I've triple-checked my work and tried to identify any solder bridges or super-obvious trace cracks but here's where my amateurism really shines and I'm left stumped and I'm hoping this is a common problem and/or easy to narrow down ?

I completely de-soldered the RF-modulator and the 4 components as per instructions.
https://www.thefuturewas8bit.com/deluxe-atari-composite-video-mod.html
http://blog.tynemouthsoftware.co.uk/2018/05/easy-atari-2600-vcs-composite-video-mods.html

If anyone can help me out it would be greatly appreciated! ?

Edit: Video didn't work so well, here's a hosted version:https://s3m.io/EszK3

Edited July 28, 2020 by Cloaked Alien

[juansolo]

I'm assuming you're in the UK. If so, happy to take a look at it for you.

[Cloaked Alien]

I'm in Sweden, but thank you for offering ?

UPDATE: Not completely solved but ground was in the wrong place. Like a complete idiot that only thinks he read instructions I put the ground cable in one of the transistors holes instead of on the pad next to the capacitor, as the instructions clearly says...

So now I've got video! Yay!

But I've also got a very terrible signal noise across audio and video. Video seems to be affected by audio as well and it's giving off a pretty decent impression of the Vectrex-buzz ^^

The PSU I think is an original Atari one, at least it says Atari, and not a 3rd party cheap PSU.

I've had cheap PSU's cause massive signal noise on both a PlayStation 2 and a Commodore 64 (by powering the 1541-II even)
 

[Cloaked Alien]

I've gone over all my work once again but I haven't been able to come up with anything conclusive ?

Done some tests though. Ground is 0 ohms from the point on the PCB all the way out to the mod connector so it does seem to be connected properly.

If I remove the Switchboard I have infinite resistance between ground and video. If I connect the switchboard I get 17.8Kohm, is that normal?
With the composite mod board connected resistance goes down to 1.5Kohm.

These are pretty much measurements just taken without knowing what I'm doing. I have no idea what to look for or what to expect ?

I did however try to desolder the audio cable for the mod and that did fully remove the audio signal interfering with video. Video was still very much snowy though.

[Cloaked Alien]

Okay, so I've replaced some components and I've literally bathed both the main board and the switch board in Isopropanol (there was some sticky residue on the boards I've found to be non-conductive but felt it couldn't hurt to try)
 

No difference at all and have yet to find a short, but at least I've ruled some things out! ?

Components replaced are the ones listed for the light sixer here.

At this point I'm wondering if I should just re-install the RF modulator O o

[nolivesleft]

On 8/6/2020 at 3:48 PM, Cloaked Alien said:

Okay, so I've replaced some components and I've literally bathed both the main board and the switch board in Isopropanol (there was some sticky residue on the boards I've found to be non-conductive but felt it couldn't hurt to try)
 

No difference at all and have yet to find a short, but at least I've ruled some things out! ?

Components replaced are the ones listed for the light sixer here.

At this point I'm wondering if I should just re-install the RF modulator O o

Watch this video - the guy doing the mod also botches it and corrects it. The instructions from tfw8b are unclear imo.

 

 

[juansolo]

On 8/6/2020 at 3:48 PM, Cloaked Alien said:

Okay, so I've replaced some components and I've literally bathed both the main board and the switch board in Isopropanol (there was some sticky residue on the boards I've found to be non-conductive but felt it couldn't hurt to try)

Sticky residue is flux, generally it's not doing any harm, but likewise cleaning it of won't hurt either.