Model 1 Sega Genesis video issue

EDIT: SOLVED!
Required replacement of proper PSU.

I got in a composite cable for my Model 1 Genesis and am having some strange video problems. I get these horizontal scanning strips that go up my screen as seen in the pictures. I took a look at the board and didn't see any obvious problems with capacitors though on the back of the board there is a resistor and some sort of solder bridge (i'm not sure if this is supposed to be there or not). Maybe this was done by a previous owner? These lines are also apparent when the console is turned off (though they don't appear when the console is completely unplugged).

Attached are some relevant images of the board/issue. Can someone point me in some sort of direction?

I appreciate it
Ghudda

 

Do you mean unplugged from the TV or with the AC adapter unplugged?

 

No, when the console is turned off but still plugged into the AC adapter as well as the TV. This only happens on my CRT though. My Plasma TV doesnt show the lines when the console is turned off.

 

And if you keep the console plugged to the TV but disconnect the AC adapter what happens ?

 

The lines go away. So it's not an issue with the TV itself.

 

Sounds like the issue is in the console. I would still try with a different known good AV cable though. Just to rule stuff out.

 

Yeah being that I only have that one composite cable, I may take the console to a local game shop and test it with one of their cables tomorrow.
I've tested the console with RF and it seems to be working fine.

 

Good plan, I have done the same in the past when I lacked spare hardware to properly troubleshoot.

Bring you AV cable with you to try it there too. Might be helpful.

 

Does anyone know anything about the what looks to be custom work on the bottom of the board? Where the resistor and bridge are.

EDIT:
So obviously the board had been worked on by a previous owner. I noticed two major points of damage to the traces on the board next to the resistor. For the hell of it, I removed the resistor and bridge and now I get no picture, just the lines across the screen. I think the issue is coming from the damage to the traces. I may just start looking for a replacement Genesis 1 HD Graphics console :/

 

Afaik its pretty common for genesis consoles to have some parts added in this fashion. Looks like factory work to me.
Maybe it would help if you tell us what board revision you have?

 

It's a TMSS VA6 I believe. FCC: FJ8USASEGA

EDIT: i've reconnected the resistor/bridge and it's back to where it ways (displaying video but still with apparent lines)

 

Just got back from taking my Genesis to the local game shop and it worked fine on their cable so I bought it. I brought it home and, what do you know, the problem still persists. Though I believe I know what the problem is. It must be in the power supply that i'm using. I have a 3rd party 9v 1.3amp power supply that I use for my Sega CD that is rated at DC 9v 1.3amp and so I would think that it'd be fine but I noticed that if I, for some reason, try using an NES power supply, the line pattern changes and the whole console displays differently. This leads me to believe that the power supply is the culprit. But at the same time, the console outputs an RF signal just fine with that Sega CD power supply so why wouldnt it work for the DIN connector?

I'll probably return this composite cable I bought today to the store and exchange it for a power supply.

 

Wait... You used an NES power supply ?

It must not be an original NES adapter because those output AC and they will fuck up your genesis in no time.

But anyway, yeah, I forgot to tell you to try a different adapter too while you were at the shop. Those are the basic things to try!
Since you were using a 3rd party PSU I would not be surprised changing the adapter fixes the problem.

Hope it works!

 

Bought a 1st party PSU and problem has been solved! Thanks for the help, Max I appreciate it!

 

glad is fixed, one thing anyway the resistor bridge is factory made. Most of the video problem of the Gen comes from the power supply.