Main > Monitor/Video Forum
TV CRT to Arcade Chassis - Issues & Where To Start
buttersoft:
Yeah, mixing working parts to test each bit is a great place to start.
For a fresh PC these days I recommend Win10 and a cheap Radeon 5450 or 7450 running crt_emudriver. Just don't get a card from a giant OEM like Dell or HP as those cause issues.
soup:
--- Quote from: Zebidee on June 28, 2023, 09:39:17 pm ---...
You can buy a cheap JAMMA harness everywhere for about $10-$15. Video signal wires clearly marked. Suggest that you grab a few cheap ones and chop away at that instead of soldering directly to your JPAC :D
--- End quote ---
Now why would I do that, I mean its not like my soldering is that bad or the fact that I can't count, how hard is it - start from the left count to 6 then, skipping the Jamma key slot, continue on counting up to Pins 12/13/14 and then solder.....
:banghead: :banghead: :banghead: :banghead: :banghead:
And there sir was my problem. Not reading the diagram correctly to see that the Jamma key slot is actually numbered (PIN 7 - what Pin , there is no pin!!). sigh.
I had, hours prior, installed Win10 along with GroovyMame + CRT_Emudriver as the PC isn't that old. Wasnt until close to midnight in checking for any shorts on the video wires I noticed in the diagram the Key Slot being numbered. So a quick resolder (moving my wires one pin down) and lo and behold I had a picture, one so rich and bright!
I do have issues where the desktop picture wont fit on the screen width wise (max board adjusted) and its a bit blurry (although I tweaked the Chassis colour pots and that seemed to get it better) especially in Mame FE however the 3 games I tried are fine (although the pre-game pop-up is unreadable). I'll need to read up more on VMMaker and presets, jumping accross to the GroovyMame forum if still having issues.
Thanks gents for guidance above, so impressed by how much better (from S-video) the picture is in games and such a sigh of relief!
buttersoft:
--- Quote from: soup on July 10, 2023, 08:47:36 am ---Thanks gents for guidance above, so impressed by how much better (from S-video) the picture is in games and such a sigh of relief!
--- End quote ---
If i may speak for us all, you're welcome :)
And yep, it's 100x worth the jump to RGB, IMO
Zebidee:
As I've learned from IT help desk operators, much of the time problems come down to making sure everything is connected right in the first place!
--- Quote from: soup on July 10, 2023, 08:47:36 am ---I do have issues where the desktop picture wont fit on the screen width wise (max board adjusted) and its a bit blurry (although I tweaked the Chassis colour pots and that seemed to get it better) especially in Mame FE however the 3 games I tried are fine (although the pre-game pop-up is unreadable). I'll need to read up more on VMMaker and presets, jumping accross to the GroovyMame forum if still having issues.
--- End quote ---
About the "its a bit blurry" - Assuming your CRT's yoke/convergence is reasonably good to start with, try tweaking the flyback. For most brands/models there will be two knobs.
The bottom knob is usually the "screen" voltage, this will influence the overall image brightness. With the actual brightness control pot in the middle position, adjust this until brightness is appropriate.
The top knob is usually the "focus". As the name suggests, adjusting this will bring the image into focus.
Every time you adjust the screen knob, you will need to tweak the focus a little to match. Once you get this looking as good as possible you should then leave it alone - use the brightness/contrast pots instead for everyday adjustments.
As you probably already know, adjusting VMMaker/presets won't affect the blurriness, but you can probably improve the screen size/fit/geometry by adjusting the frontporch and backporch values.
--- Quote ---Thanks gents for guidance above, so impressed by how much better (from S-video) the picture is in games and such a sigh of relief!
--- End quote ---
Cheers :D :cheers:
soup:
--- Quote from: Zebidee on July 11, 2023, 09:08:12 pm ---
About the "its a bit blurry" - Assuming your CRT's yoke/convergence is reasonably good to start with, try tweaking the flyback. For most brands/models there will be two knobs.
--- End quote ---
Bingo - didnt realise there was these two adjustments on the flyback (assumed they would of been one of the board pots), slight adjustment and the text is now so sharp and well defined (I'm stoked).
Some games the screen was trash, had fixed some (found a post from one of you above 'dotclock_min 8.0') but there's another group that I need to address (still investigating) and find a front end - so sad MaLa is no more :(