Sega Hardware Repair

Hi all!!! I've got two consoles Sega Mega drive broken... One (MD1 VA6) turns on but nothing apears on screen, only a flash when I turn it on and a little buzz on sound (that stops in 1 second). This appeared after trying to overclock the 68k (which is an Hitachi), and I don't know what may cause it. I've undo all the conections but problem remains...

The another one is an MD2 VA1 (thank God compatible with TmEE's CCAM:cool:)which doesn't turn on :(... The heatsync heats but the console doesn't turns on. The connector was fully with corrosion and around him too. I've cleaned all corrosion but the led doesn't turns on (I didn't put any cartdrige because when the led doesn't light on there´s problems). :(



Someone knows how to solve this kind of problems?

It could well be that your VA1 MegaDrive 2's LED doesn't work. If the heatsink gets hot when you press the power button, electricity is flowing through the unit. Before considering it "dead", I'd plug in a cartridge first. Maybe it's just the LED that needs to be replaced.
As for your VA6 MegaDrive 1, it could be that the processor's dead. Did you disconnect the old 7.6MHz line on the board before overclocking it? If you didn't, chances are your Hitachi 68000 is dead. Or maybe you used an oscillator that has too high a frequency? What was the value of the oscillator? If that's not the problem, the cartridge slot may be loose or the pins are not making a contact with the cartridge.

Yeah. I think it's the processor because after few minutes turned on, its nucleo starts to overheat, almost burning!!! I'm gona check MD2 led.

Replace your 68000 ASAP. And use a Motorola one, those ones are a lot more stable for overclocking.

I can't, I don't have a spare 68000... :( And I don't know where to get it without screwing a console :?

Do you buy things off of eBay? If so, look here: http://cgi.ebay.com/MC68000L8-68000-...QQcmdZViewItem
This one can operate between 4 and 8MHz. You can always look around eBay, there are several Motorola 68000s for sale.

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Originally Posted by Ace

Do you buy things off of eBay?

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Yes. This one is too expensive but I'm gona search other ones.

I did find one for cheaper, but it comes from China(I usually don't trust Chinese sellers). Maybe you do?

Sometimes, for me it's always according to the seller feedback and "feeling" of trust...

For MD2, seems like the 7805 (the chip on the heatsink) might still be dead, even though it warms up... take a tester and see if there's 5V on the 3rd pin of the chip.

The MD2 led is broken :D But although this, the games refuses to boot. I'm gona check the cart connector.

dead LED and bad 7805 means nothing good.... there's a great chance the whole thing is dead

Change the IC power regulator (7805) just to see if there is any improvement...

I think the 7805 works well because my Mega Cd works fine with that md2 and when I turn the console on the "PRODUCED BY OR UNDER LICENSE FROM SEGA ..." screen apears, but then nothing more when the cartdrige is introduced... I think it have a loose cart connector.:?

yup, bad cart connector... I have a fix for that, well, no me :P
http://www.mmmonkey.co.uk/console/se...loose-cart.htm
http://www.mmmonkey.co.uk/console/se...loose-cart.htm

Just don't push too hard, otherwise you will have the rows touch each other which means no MCD unless you put some paper in the cartslot :)

I'm gona try that tomorrow (or today -1:06 AM in Portugal :)). There's a lot of dust in there too...


EDIT: No success... I'm gona replace the connector, and pray that this method works...

i have the same fault

Hi, and Welcome to Sega-16. Try to do what TmEE describes bellow and give some feedback.

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Originally Posted by TmEE

yup, bad cart connector... I have a fix for that, well, no me :P
http://www.mmmonkey.co.uk/console/se...loose-cart.htm
http://www.mmmonkey.co.uk/console/se...loose-cart.htm

Just don't push too hard, otherwise you will have the rows touch each other which means no MCD unless you put some paper in the cartslot :)

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Quote:

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Originally Posted by TmEE

yup, bad cart connector... I have a fix for that, well, no me :P
http://www.mmmonkey.co.uk/console/se...loose-cart.htm
http://www.mmmonkey.co.uk/console/se...loose-cart.htm

Just don't push too hard, otherwise you will have the rows touch each other which means no MCD unless you put some paper in the cartslot :)

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Just some notes about the info in that link:

1) leaving games in the cart slot does not, I repeat, DOES NOT age the cart slot any more. A normal game should not displace the pins enough to go through plastic deformation. In my experience, 99.9% of the time either the game is dirty or the pins are corroded. If its the game, clean the game with rubbing alcohol (50%) and a q-tip (plastic stemmed). If it is the pins, you can try scraping it off with a small scraper, but thats the most you can really do, but odds are if its corroded, there is probably much more significant damage and it might as well make it to the trash can.

2)if you decide to try to bend the pins back, only do it a SLIGHT amount. The pictures he shows are way more than you should do, going that far risks strain hardening or necking, either of which could lead to a loss in overall toughness and elasticity meaning you will either have to repeatedly bend them back or that they may even break off completely with use. Again, unless it has been abused (like someone put in a cart forcefully at a bad angle or yanked it forward and back while it was in there) bending the pins back is probably not the right way to go, the problem is probably in the cleanliness of the material on the cartridge or the pin connector itself.


P.S. is the Genesis cart slot removable? if so, I have heard Weiman's cooktop cleaner is good for cleaning pin connectors (thats what the big time NES reseller crowd uses) with a toothbrush. If you don't want to buy/try that, rubbing alcohol would probably work as well, but you might have to soak the connector in rubbing alcohol overnight before attacking it with a toothbrush/metal pick.

P.P.S. for the record, just so everyone knows, under NORMAL, NON ABUSIVE use pin connectors DO NOT stretch out or lose their grip. My original NES from 1990 still has almost as strong of a grip as the kung fu grip replacement connectors and boots up all of my original games first try (and most of my used games except for ones with especially bad pins, those sometimes need a reinsertion or two), and i used to play my NES EXTENSIVELY back in the day and changed games often. Its all a matter of user care: if you slam your games around when inserting and removing them, you'll probably bend the pins. If you let your games sit out where they get dirty, you'll probably corrode the pins. If, however, you take good care of your games, store them in a clean, moisture/dust free, and room temperature environment (not the garage), there is no reason games or pin connectors should fail, ever (until they get so old that the components literally fall apart).

My MD2 has its cartslot dead, and the pin bending did help... bit the result didn't last too long, so I jammed 1cm long pieces of wires behind each contact... now the grip is so tough you can shake the system while holding it from cart and nothing happens... good for 32X too... putting something behind the pin will make the pin go straight, and thus increase the contact are aswell... if you remove the additions, the slot can be considered useless.

i have a sega mk1 console i have checked and replced 2 7508 and changed the z80 cpu but still dont work
its unmoded

what are his sintoms? She turns on?

64 pin the cart slot
it may need replacement
where can i get