What would cause this arc?

TonK

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DSC02256.jpg


I checked my system, no damage or anything - mine didn't cause it.
 

arfink

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Wow, that's a nasty one. MVS or AES? I assume it's original, right?
 

Kunio

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That arc forms when Elvis leaves the building.. Crack the case open and check what it looks like inside. Probably a chip that shorted out or something. Please post pics if you can, as it would be interesting to see.
 

mainman

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Those are the 5 volt connectors and that kind of scorching does occur rarely due to excess current.
 

TonK

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That arc forms when Elvis leaves the building.. Crack the case open and check what it looks like inside. Probably a chip that shorted out or something. Please post pics if you can, as it would be interesting to see.

Nothing inside, already opened it.
 

channelmaniac

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Shorted ROM or capacitor causing WAY too much current to be pulled.

If that happened in your board check the slots because they will be damaged too... and if it was one of the MVS boards that has the right angle connection to the main board then those connectors may be toast as well.

That's cooked bad enough that you'll need a donor board to repair that cart. Pull the good ROMs and put it on the donor board then burn an EPROM to replace the bad chip. Or, swap all the ROMs and toss the bad board with the shorted cap away.

RJ
 

TonK

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Shorted ROM or capacitor causing WAY too much current to be pulled.

If that happened in your board check the slots because they will be damaged too... and if it was one of the MVS boards that has the right angle connection to the main board then those connectors may be toast as well.

That's cooked bad enough that you'll need a donor board to repair that cart. Pull the good ROMs and put it on the donor board then burn an EPROM to replace the bad chip. Or, swap all the ROMs and toss the bad board with the shorted cap away.

RJ

I got it like that, as mentioned earlier.

I talked to the original owner yesterday who says there is no damage to his MVS

My board is fine, no damage at all.

In fact its in attract mode right now, cycling fine.
 

Arcademan

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Gotta agree with the others...very odd the main board was burnt free and the cart was but then I've seen stranger things. My 6-slot board currently has a big burn mark around one of the +5 JAAMA connector: had to bypass it into the other +5's to keep it running.
 

ttooddddyy

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My 6-slot board currently has a big burn mark around one of the +5 JAAMA connector: had to bypass it into the other +5's to keep it running.

That is common on the MVH6 as they draw a fair bit of current from the edge connect, the 5 volt connections get hot and toasty.
I used some solderwick to fix my 6 stots.

th_sammiccam084.jpg
 

Xian Xi

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That is common on the MVH6 as they draw a fair bit of current from the edge connect, the 5 volt connections get hot and toasty.
I used some solderwick to fix my 6 stots.

th_sammiccam084.jpg

Is this common even when using all 4 +5v points? Would it be better to make 2 more +5v entry points to disperse it better?
 

Arcademan

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Is this common even when using all 4 +5v points? Would it be better to make 2 more +5v entry points to disperse it better?
One would think but until I fix my particular board burn, I'm only using 2 and have the other +5 wiring tied into those. Not a good situation but it keeps the game running and the tokess flowing into it.
 

Xian Xi

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Maybe a distribution block would be best to avoid that from happening. Maybe send it to the jamma edge and 2-4 other caps on the +5v plane?

What's the worst pic you have of that happening to an MVS or jamma board?
 

channelmaniac

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I guess y'all are forgetting the connectors used to get more 5v power flowing between the top & bottom boards.

They aren't populated on most MVS boards but the solder points are there. It wouldn't take much to put a connector on those points and use them for getting additional power to the boards.

It sure beats soldering to capacitors. ;)
 
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