Sega Genesis 3, help needed.

[Argelfraster]

Just purchased a Genny 3 from Ebay with some games, controllers, power cable, but no AV cable.
I cracked it open and wired it up to my PSone screen for testing.
Long story short the genny isn't outputting video.
I checked it with a multimeter and it seems the 7805 is not getting any power. Should I wire the power cable straight to the 7805 to see if that works?
Any suggestions?

 

[zeturi]

You can send voltage into the 7805 if you want, or try bypassing the 7805 entirely, and sending straight 5v into the output spot. If it still isn't working, then something on the board might be fried. Try using another game, if you can, and see if was just the cartridge. Speaking of which, have you relocated the cartridge slot yet, or is it still in it's original spot.

 

[Argelfraster]

Nothing has been done to the system, I just took it apart and soldered to it.
Ill try wiring to the 7805 or bypassing it soon.
Thanks for the help.

EDIT:
No video still, although I have no tried to bypass the 7805 yet, I checked with my multimeter again after bridging the power jack and the 7805 and it seems now the 7805 is receivcing 10v and outputting 5v, but I still dont get video. It may be because the Psone screen I'm using is fried. No other screen to test on. Should I get an AV cable?

 

[zeturi]

Nah, just tear apart one of those rca to rca plugs, the kind you use for a DVD player, and cut one of the ends off for a ghetto av cable. They're pretty common, and cheap, and you won't be left with an otherwise useless Genny AV cable. Here's the pinout for the Genny 3 in case you haven't seen it yet: viewtopic.php?f=34&t=3136

 

[vskid3]

10v

Wait, was the PSone screen running on 10v, too? If so, it may be dead. Anything over 9v is considered risky with them.

 

[Argelfraster]

No the Psone was running off of a Psone power supply, so no worries there.
I'll try to rig up some kind of AV cable for the Genesis today and let you know how it turns out.
I planned on putting this Genesis into a JB55 with a 4.3" screen, but now that I have the case, it seems that a 4.3" screen will not fit.
Has anyone else tried using a screen that size with this case?

 

[Argelfraster]

Well the Genesis is not working at all.
I'm going to try it again in a while, but I'm not feeling positive.
I'll probably end up buying another board if no one has any idea of what is going on.

 

[Argelfraster]

So it turns out the wiring diagram I was using was incorrect, but I figured out the wiring and fixed that, now I ran into another problem.
The genesis will display video for 2 minutes tops and then either freeze or get psychedelic lines moving all over the screen.
This happens either when I let the system run for that amount of time or when the system gets nudged or touched.
I used a cartridge slot from a different Genesis 3 for a cart slot relocation so that I could keep the original one for testing if the relocated one didn't work.
The same problem happens when the Game is in the original cartridge or in the relocated one. I'm stumped.
Can anyone help? I can post pictures or a video tomorrow if needed.

 

[zeturi]

I would check the soldering on the motherboard side of the cart slot relocation. If it happens when the system is moved during testing, or when you insert a game cart, then I would say it's the relocation.

Still, if you can, post up some pics or a vid, it would help.