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The Jassifier

I'm thinking there's an inadvertent soldering bridge, looks like one of the video signals is bridged to ground.
 
I've ordered a replacement SCART cable, since I'm beginning to suspect it being the primary fault.

In the meantime, I'm going to attack this thing with a multimeter, see if I can't find this bridge, since my busted-ass eyes can't seem to locate it.

EDIT: I looked over the close-up pictures a little more, and noticed that some of the resistor legs have gold circles around them, and others got filled in with solder from the back of the board. Maybe that's the cause? It's the only thing that's consistent between all three boards. I'll try fixing it and see what happens.

EDIT THE SECOND: Tried everything I could think of. Multimeter shows no bridges. Waiting for the new cable before writing this batch off entirely.
 
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Got an update:

New cable arrived, and I get the same result. I must have screwed the same thing up in all three of them. What that is, I don't know. I can't see it. What I do know is that the pots seem backwards. I turn them to the right, and the picture gets brighter. This is labeled as "-" on the board. Left is "+". I turn it left, and it goes dark. Seems wrong to me, but I don't know a damn thing about any of this.

Guess I'm ordering a new batch at some point and trying again. Or just buying a completed one from someone else.
 
Would there be interest in pre-made boards? I've ordered PCBs from JLCPCBs for my CMVS, and could possibly order a set of Jassifiers from them and include the BOM on my next digikey purchase.
 
Is this "jassifier" the best option for consolizing a MVS mobo? I I am thinking to edit it just to remove the vga connector, or just order it as is, and solder cables directly to the pcb.
Seems like regular pcbs and MVS outputs are a bit different levelvise?
 
bytestorm said:
Is this "jassifier" the best option for consolizing a MVS mobo? I I am thinking to edit it just to remove the vga connector, or just order it as is, and solder cables directly to the pcb.
Seems like regular pcbs and MVS outputs are a bit different levelvise?
Click to expand...
I have yet to try a Jassifier, but I've had great luck so far with this circuit: https://oshpark.com/shared_projects/R8NJ9UQ4
 
avramce said:
bytestorm said:
Is this "jassifier" the best option for consolizing a MVS mobo? I I am thinking to edit it just to remove the vga connector, or just order it as is, and solder cables directly to the pcb.
Seems like regular pcbs and MVS outputs are a bit different levelvise?
Click to expand...
I have yet to try a Jassifier, but I've had great luck so far with this circuit: https://oshpark.com/shared_projects/R8NJ9UQ4
Click to expand...
oh, I thought ppl were having problems with a dark picture with that one? Maybe I mixed them up with something else?

EDIT: I re-read the thread and ppl were having some trouble with it :/.. I want to use it with a regular consumer TV (rgb scart).
 
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bytestorm said:
I want to use it with a regular consumer TV (rgb scart).
Click to expand...
"The PCB offers the option to connect a consolized NeoGeo MVS with impedance matching RGB and Sync signals to a regular TV."

Then this is the device for you I guess (don't know anything about it or dark image "problems" using it however).

I can tell you my device is intended for use with the OSSC, thus will NOT process the sync signal whatsoever.
The correct approach for OSSC, but not if you'll be connecting to a consumer TV (you'll likely need some form of sync stripping to achieve a stable image).
 
bytestorm said:
avramce said:
bytestorm said:
Is this "jassifier" the best option for consolizing a MVS mobo? I I am thinking to edit it just to remove the vga connector, or just order it as is, and solder cables directly to the pcb.
Seems like regular pcbs and MVS outputs are a bit different levelvise?
Click to expand...
I have yet to try a Jassifier, but I've had great luck so far with this circuit: https://oshpark.com/shared_projects/R8NJ9UQ4
Click to expand...
oh, I thought ppl were having problems with a dark picture with that one? Maybe I mixed them up with something else?
EDIT: I re-read the thread and ppl were having some trouble with it :/.. I want to use it with a regular consumer TV (rgb scart).
Click to expand...
not at all, I've used it in 10 or so builds, and have not had any issues with the picture being too dark
 
avramce said:
bytestorm said:
avramce said:
bytestorm said:
Is this "jassifier" the best option for consolizing a MVS mobo? I I am thinking to edit it just to remove the vga connector, or just order it as is, and solder cables directly to the pcb.
Seems like regular pcbs and MVS outputs are a bit different levelvise?
Click to expand...
I have yet to try a Jassifier, but I've had great luck so far with this circuit: https://oshpark.com/shared_projects/R8NJ9UQ4
Click to expand...
oh, I thought ppl were having problems with a dark picture with that one? Maybe I mixed them up with something else?EDIT: I re-read the thread and ppl were having some trouble with it :/.. I want to use it with a regular consumer TV (rgb scart).
Click to expand...
not at all, I've used it in 10 or so builds, and have not had any issues with the picture being too dark
Click to expand...
Great to hear! Then I will give it a shot. Wonder why some ppl experienced dark picture thou.. must have been extra componens in the cable maybe?
Thanks for the info!
 
Well, I'm now 0 for 6 on these boards. ALL of them are showing the exact same problem(s) despite changing everything else in the chain, and I can't pinpoint the fault on the boards with my multimeter. I'm throwing in the towel, unless you guys have more ideas on what I screwed up.
 
@DoktorSleepless sorry you had a bad time with the PCB... I think I'll do another run of them soonish, mine will be assembled and tested before sold.
 
@jassin000 I'm a goddamn idiot. I managed to get it to work. I was right. There's nothing wrong with the boards. I just didn't set the 5V switch on the Jammafier. Might be something to clarify for future users... Set that switch to 5V or the damn thing doesn't work!

IMG_20201018_134739.jpg


Results! (Ignore the monitor being in Tate mode, I wanted some Ikaruga action while waiting for that second round of PCBs to arrive)

IMG_20201018_134642.jpg
 
I built two of these last night and I got it right the second time at least.

On the one that doesn't work the OSSC gets sync but just displays black. My soldering looks fine and the only thing I did different on the second one was the orientation of C5; does it matter which way C5 is installed or should I look else where for my issue? I only need one but if can get this second one working and get the third one assembled and working and I can pass them on to whoever may need one at cost.

Overall this little board works great, thank you for sharing @jassin000 and everyone else who helped.
 
statix138 said:
On the one that doesn't work the OSSC gets sync but just displays black
Click to expand...
I'm thinking check the RGB lines, on C5 all mine faced the same way (but I don't think it matters).
FbSR1IK.jpg
 
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