What's this Mega Drive mod do?

Stop this seriously, constructive comments from now on. Deal?

 

x

 

and yet two of you can't stop giving lots of excrements.
i made it a point, that it was a guess, inb4 wellspoken and wellmannered gentlemen such as yourself would start tossing excrements. Still, it somehow went right above your enlightened minds.

 

Ok guys. Back on track.

Whatever you do. DO NOT REMOVE THOSE CABLES THEN POWER ON THE BOARD. I did so, and as soon as I plugged it in, I heard plastic burning, a whine, and started to smell a horrible smoke.

I tested this on the VA1.8, and those wires actually connect to two pads under the solder, like they were designed to be there. I'm just glad nothing bad happened and such. Sure worried me though. @americandad @Bad_Ad84

 

Excellent point. Sigged.

EDIT: Welp... nvm. The post is too long. Disappointing actually...

 

@SwampFox56 Hey, at least now I know what sigged means (thanks, google)

Lol at "nothing bad and such" . That sounds pretty bad imo.
It would be nice to see som photos of these "pads".

 

For all those wondering. This is the same VA1.8 board with the wires gone that starting frying itself with them gone. Those are indeed dedicated pads for that work. This had to be engineered for them. @americandad

 

What I asked earlier in the thread was if there were any vias under the solder (you will need to use braid to remove the solder). Already said that it looks like a pad that was designed to be there.

This was all to see if there was a manufacturing defect (like had been suggested earlier) and the vias didnt actually connect to the trace. So soldering to the top of the vias would fix that.

But so far, this seems like it was designed to be there - which was never disputed. Always said it seems sega must have had a reason for doing it, rather than it being a defect that was fixed after the fact. Just trying to figure out why its needed.

 

Same

 

x

 

I am planning to measure the resistances and voltages when my console arrives.

Will also be running it without the wires to test.

However, I have also been told that some boards of the same revision DONT have these wires and work fine. Maybe they subbed out where they were made and its limited to one factory's boards vs anothers?

Also, you arent bypassing that trace (on ops board anyway, not the one with wires to the folter) - its a wire to the same trace, the current still needs to go through the vias. Then you have the same problem on the other side of the board, but that seems fine...

Edit because of your edit:
Can you share the pics?

 

x

 

The holes would make the trace effectively narrower and thus increase it's linear resistivity along with the heating. This is a very reassonable hypothesis, and what I'm saying since the beginning...

Hopefully Bad_Ad84 can verify for sure, it's a very interesting situation!

 

Maybe its what trimesh said - weight of the copper. But maybe it was limited to one factory and not another?

As it seems you have a VA1.8 with the issue but also ones without. Then you have VA2 with and ones without.

So there is an issue with some and not with others - seems like maybe an issue at one factory?

@Druid II - Do you have info based on serial/board revision like with the saturns on where they were made?

 

The linear reisitivity is basically the area of copper in a section cut perpendicular to the trace (for DC anyways), so it's completely logical a thicker copper clad would fix the issue.

 

x

 

Your meter may not be able to measure it very accurately. I have an LCR meter with much finer resolution and accuracy.

However, there is no guarantee the MD2 ive ordered even has the wires! =/

So we are all on same page, the "holes" are vias - which are plated holes that link different layers of the circuit board together.

Regarding the board revision numbers - they are the same, except for the last part. Maybe thats the factory code that made them? rather than minor revisions?

 

x