Problem while switching on genesis

I'm sorry for posting a topic out of nes stuff
I bumped into a terrible problem....There is a weird sound and black screen like on the following video when I switch it on :
http://www.youtube.com/watch?v=_rE2e-GbTFs

And I noticed the following :-
1-The longer I keep it switched on , the more it functions properly and the problem slightly solved (the sound volume decreases).
2-When I switch off the devices and the electronics that consume much electricity , it functions properly and the problem slightly solved.

And these are the images of the board from the front and the rear part :

bottom left


bottom right 1


bottom right 2


center left


center right


Top left


Top left (clearer)


Top right


Top right (clearer)


whole board


I'm really confused where the problem is
BTW the reset button doesn't work till I press it strongly several times...and I'll keep the rear part images till it's necessary to diagnose the problem
and I'm sorry for posting many pics.

They are known for horrible capacitors.

The horizontal stripes and hum are pretty good indicators that your AC adapter isn't providing enough power. Try using another AC adapter (10 volts, at least 0.85 amps, positive tip) and see if that fixes it.

I just want to point out that this is a clone system...

Whoops, I guess I missed the complete lack of Sega logos.

I still think there's something wrong with the power supply.

tell me plz where exactly the capacitor is..and why don't u suppose the ac adaptor is the problem source?

yes I agree with u but why the problem isn't the capacitors like 3gengames said

Everything you've described is consistent with using too small of a power supply. What are you currently using? Try using something capable of providing more amperage. (And, depending, maybe more voltage. What's written on the two parts in TO-126s in the big metal heatsinks to the left of the cartridge slot?)

Sounds sticky to me. How much has this console been used? (I see it was manufactured in 1994)

no I don't think so for these reasons
1-it was made in japan
2-it has a manual in many languages including arabic.
3-I have the original controllers and the ac adapter till this day and they're featured with their long age and strength and they still work after several times of falling and abuse (unlike the clone ones which are featured with weakness) except the ac adapter 'cause they fell several times and btw it was bought it for more than 17 years.

I don't have enough experience in this suff so could u tell me how u knew that it's a clone..may be I'm wrong

i'm using this ac adapter
input:220VAC 50HZ 14W
OUTPUT: 10V DC 850mA MAX

I don't know which place u mean?do u mean the two parts below the cartridge slot?


Resest button doesn't work at all now even after pressing it several time.
My brother bought it for approx 17 years , but I maintain it and use it a little.
where is "1994" written?

do u mean it's clone?..BTW it's mega drive not genesis.

That thing is 100% definitely a clone, but what is called a superclone that uses exact copies of the original chips (same pinout too !).

And what you experience is definitely too weak power supply. You need at least 1A (the more the merrier) and more than 7V (but less than 18V).

but as u see what I described above..the adapter is 10V namely more than 7V , so how is it too weak?
and where "1A" is written on the adapter?I can't find it.

It's both a Mega Drive and a Genesis!

Yes, it's a clone. A real Mega Drive/Genesis would have the Sega logo silkscreened on the PCB and a few of the ICs. I've found some pictures here if you'd like to compare your clone to real Mega Drive hardware.

The clone looks like it uses Mega Drive 1 parts in a Mega Drive 2 form factor. Maybe the chip manufacturers didn't anticipate Sega changing the board layout?...

Because it's broken.

The brick can be 20V too but if it only gives out 0.1A it will not be able to do anything. The brick you have probably does put out only about 500mA, and at that point voltage drop is so great it has problems keeping power regulators operational. There's maybe 6V left when you go and measure the brick output while the system runs.

no there is a difference between them in form


no I mean the original one is broken but I had bought a clone one that I'm using currently and I can't find the "1A" on this adapter but I really found it on the back of the console.

1.0 A = 1000 mA, so it'd be written where "500 mA" or "850 mA" would otherwise be. For example, my power supply for another console says "OUTPUT DC10V 850mA".

Yes I got it sorry for my physics
converting mA to A = 850mA x 10-3= 0.85 A< 1.0 A
am I right?
I told the seller to bring me Genesis Adapter , he brings me a weak one Go home seller u're drunk
so I should buy adapter with 1000mA or more?

That should be enough voltage. Other people claim you need more current (but I don't know). Do you have a multimeter? If so, make sure that when you're playing, you see at least 7V going into the connector where you plugged the adapter into the Genesis.
I meant these two:


First, you should make sure that it's the switch that's broken:
Once you've gotten the genesis to meaningfully turn on, connect the two areas I've colored in yellow here, to make sure it resets. If it does, you can find another microswitch somewhere and get someone with a soldering iron to replace it.

On all the ICs. They're labeled "TA-07 9447", "TA-05 9446 1436258064", "TA-06 9444 1437395065C ", "MB84256-15LL 9019 M86", "LH0080B Z80B-CPU SHARP JAPAN 9238 1B", "MB84256-15L 8746 M69", "MC68000P10 4C91E DJQUA9450"

no they're right cause I read the details on the back of the console and it says 1A.

ok I'm gonna tell u what's written there , but r u sure there's something written on these two heatsinks?

sorry again plz tell me what I should do in detail...should I connect them by wires?and I can't understand the areas that r marked in red..do u mean I should connect them with each other?
and the red mark number 2 how should i connect it?

I really want to fix it so help me and tell me what I should do in detail 'cause I don't have much experience and thanks in advance.BTW it was working like charm till 2 years ago.
when I want to reset I switch off and on the console and that really makes me sick

Not on the metal; on the black part to the left. I'd guess one of them should be a 7805 or something, but I don't know what the other is. (If there's text covered by a screw, don't worry about it, it's not important)

Yes, temporarily. When connected, it should be equivalent to holding the reset button.

The switch looks like this:A is always connected to C. B is always connected to D.
What I want you to test is find out what happens when you connect either of the pins on the left to either of the pins on right.

Moving parts get old and fail. Fortunately tactile switches are one of the things that never change.

The seller sold you an adapter that can power a real Genesis 2 (my Genesis 2 is rated at 10V, 850mA) but not your clone.

Since your clone system looks a lot like a Genesis 1, you probably need a 9V (or 10V) 1.2A adapter.

the label on the console back says "1A"...so u recommend me buying what.. 1A or 1.2A?
BTW I bought the genesis from Japan but the adapter from here egypt and I'd love to say that most consoles in egypt are just clones

1A might be enough, but higher is better.

u mean higher whatever values?

The Amp value. It needs to be higher than 1.2A, or so we guess. It can say 1000A, it doesn't matter, as long as it's 1.2A.

concerning the reset button , I connected the left to right so what next?

I tried pressing it but nothing worked
and u asked for the two black parts..written on them "MT or AT(or something like that) and beside it ML" and below them "7805A"

Oh, sorry, that wasn't a fix! just a diagnostic. Anyway, I didn't mean permanently connect them, but temporarily. (You also only needed one of the two wires.) With the wire permanently attached, the genesis should permanently be being reset. You want to temporary and briefly connect them once the genesis starts playing a game and see if it reboots.

If you have a multimeter / continuity meter:
1) While the genesis is off, make sure A and B are not connected
2) While the genesis is off, see if pressing the button makes A and B connect
3) If both or neither: the problem is somewhere else
4) If only either one: the button is damaged.
4a) If only #1, use a multimeter or a wire to short A to B once a game is running
4b) If only #2, cut away or desolder and remove the button, then do the same test as above (on the holes the button was in)

How odd, they're both 7805s. Well, no matter.

yes both have the same characters.and I'm gonna remove one of the wires

what if I don't have a multimeter ...should I try 4a and 4b?
and another question do u think that the adapter might be the cause of the button problem?

Reset on MD is edge sensitive not level sensitive, wiring it shut will not generate any infinite resets.

Those switches the clone has go bust very often. I am actually tempted to trade real MD2 for that clone... I like me some superclones

In light of what TmEE says ... go for it. As long as you're careful to not damage the PCB.
Or maybe see if he's interested in following through on exchanging a real MD for your clone.

You may as well wait until you have a large enough power adapter: it will be a lot easier to test whether the reset button is working if you don't have to wait for things to warm up.

(but I doubt that it's the cause)

how would the PCB be damaged?do u mean while soldering?

Yes. Things done while desoldering, including heat and moving things, can cause layers on the PCB to peel off. Thus "be careful"