Sync Issue with K4901....video inside

sk8ersublime

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Hi guys,

I put a K4901 into my Mario Bros, and I had it all working when directly connected to the monitor, of course the video was negative because i didnt have the inverter board.

So my wife bought me the inverter board from Mikes arcade. I hooked it up, turned on the game, had sound and I had color! but the game was out of sync.

I could get it partially synced, the top would sync fine, but the bottom half of the screen would bounce left to right.

When I started playing with wires I saw a small spark, and then the sync was completely off.

Here is the video of the issue I am having now....

http://youtu.be/uEUW87Vy3Gk

what should I check first for bad H or V sync parts? I rather not buy a new chassis unless I have to, ideally I would like a sanyo, but I cant find one for a decent price in the area.

Any help is much appreciated!

Thanks!
Chad
 
Have you checked to see if the sync is good when connected directly to the monitor again? That will tell you if you have an issue with chassis or the inverter.

I haven't used Mike's inverter, but remember that the nintendo monitor wiring is not the same as normal wiring:

Normal:

Red
Green
Blue
Ground
+VSync
+HSync

Ground
-VSync
-HSync

Nintendo:

Green
Red
Blue
Ground
Ground
-CompSync

So, it's possible you had your sync wiring hooked up wrong, but for now you have to check to see what the problem is. Even if you blew something on the chassis, it shouldn't be too hard to fix...
 
Have you checked to see if the sync is good when connected directly to the monitor again? That will tell you if you have an issue with chassis or the inverter.

I haven't used Mike's inverter, but remember that the nintendo monitor wiring is not the same as normal wiring:

Normal:

Red
Green
Blue
Ground
+VSync
+HSync

Ground
-VSync
-HSync

Nintendo:

Green
Red
Blue
Ground
Ground
-CompSync

So, it's possible you had your sync wiring hooked up wrong, but for now you have to check to see what the problem is. Even if you blew something on the chassis, it shouldn't be too hard to fix...

I'll have to rewire the WG to nintendo cable I made from before. I will try when I get home tonight. I'm pretty sure it's wired right. But I haven't tried bypassing the board yet
 
if you need to fix that 4900 bring it by.

and/or make me a trade offer i cant refuse and i'll sell/trade you a sanyo ready to go.

Peace
Buffett
 
Ok so I tested the connection straight from MB to the monitor and it synced perfectly! So the monitor appears to be good.

So question about wiring from mikes inverter board to WG 4901.

The output on the inverter board has pins 5&6 both labeled as composite negative.

So on the WG side I have these pins going into the single wire that jumps the two negative sync pins together. Is this the right way? How else do I need to connect this? When I connect the board directly to the monitor I take the nintendo composite sync and put it on this wire and it's fine....
 
Ok. So talked to Buffett while playing around with the different combos of sync wires and trying pin 10 and I could not get anything working. So I said I was gonna go and just have to contact mikes arcade and see what they say... Then Buffett says " unless you wanna try connecting the sync to pin 9 maybe is converting the composite to neg. Vertical sync." I hang up and BAM perfect picture!

Mikes arcade needs to change the documentation, I will be contacting them.

Thanks Buffett!
 
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