Ok, so here we go with the what's connected to where guide for this mod. As it goes it's not too hard to do. Note this is for VA0 and VA1 mainboards only AFAIK. The screen itself is available for most GG variants, but the 'no wires' ribbon isn't available for all.
NOTE: The 'no wires' ribbon has several T10 pigtails and a clock pigtail. These can be cut off if they are not needed for your board. I chose not to do that, but rather just insulate them with tape. Either method is valid, but don't cut them off until you've checked wether you need them or not.
Also, be aware that you are soldering a plastic ribbon, so don't dwell too long with the iron
First off, once you've got the disassembly done and removed the old screen, and cleaned up as advised, then you need to get the ribbon fixed to the connector where the old screen was connected as below:
- PXL_20231013_144954023.jpg (437.27 KiB) Viewed 152 times
If the board has a '1' silk screened on it, this should be lined up with the first pin of the ribbon. If there is no '1' on the board, it is the 6th pin in from the left. Tape the ribbon down to the PCB and carefully solder the ribbon to the edge connector as per the picture and make sure there are no shorts. Note pin 1 and 2 are connected together, this is fine.
Line the little pigtail up with the 2nd pin along of the top row of the cartridge port, and solder that onto the same pin. Fold over the long piece of ribbon cable to M10 and M11 on the PCB and solder the two connections as per the picture.. Tape down for good measure.
Next flip over the board and bend the ribbon over. Locate T10 on the PCB, and the small via in the middle of the ribbon:
- PXL_20231013_140202152.jpg (247.09 KiB) Viewed 152 times
And using something to hold the ribbon close to the board, solder the via in the ribbon to T10. There is a little pigtail you can use to connect to T10 instead, but I chose to use the via:
- PXL_20231013_140347756.jpg (348 KiB) Viewed 152 times
And completed:
- PXL_20231013_140937809.jpg (339.22 KiB) Viewed 152 times
Next solder the ribbon to the back of the new display as per the picture:
- PXL_20231013_145125181.jpg (441.74 KiB) Viewed 152 times
And then locate FB1 on the motherboard:
- PXL_20231013_140925676.jpg (285.92 KiB) Viewed 152 times
And solder the large via in the ribbon marked 'CLK' to that.
One final item, which was a gotcha for me was a connection from the right hand side of C38 to *1 on the ribbon cable as below:
- PXL_20231013_155348340.jpg (337.66 KiB) Viewed 152 times
It's the green wire in this image. If you don't do this the screen will cycle through the 4 scaling modes and you won't be able to use the GG. This is shown as a long ribbon cable pigtail in the images I've seen, but it isn't on the ribbon I have, and my kit didn't contain such an additional ribbon.
Before reassembly, you need to remove the rubber surround on the inside and trim off 8 little plastic nubs, plus the post for the security screw. The Benn Venn instructions I linked to earlier give details of this.
Also, the metal shield has some fingers as seen here:
- PXL_20231013_155258135.jpg (333.14 KiB) Viewed 152 times
And these need to be trimmed off, though in my case I folded them under and flattened them down before reinstalling the shield:
- PXL_20231013_160521796.jpg (269.97 KiB) Viewed 152 times
This is necessary because the case won't fit with the fingers as they are, since they catch on the new display.
And all that's left then is to reassemble. Note there is a 3d printed frame in the kit, it's fairly obvious where this goes as it holds the display in place on the front of the PCB.
Screen quality is overall very nice and bright:
- PXL_20231013_214636650.jpg (364.61 KiB) Viewed 152 times
You can add/remove scanlines by holding Start and pressing up/down and you can change the screen modes by holding the start button, which will cycle through them.
Next I think I need to look at a replacement screen bezel as mine is quite badly scratched, though I may try and polish it first, and the amplifier is pretty poor, so I will recap it, and if it is still rubbish, then I'll replace with a modern one.
Overall pretty pleased with the upgrade, just annoying that the 'no wires' ribbon install wasn't well documented, but hopefully this will go someway to address that.
