nfg.forums

Hi!

I just ruined my third dreamcast. 
I am working (if you can still call it that) on an internal vga port.
I am following mmmonkeys guide on the internal vga.

My main problem is the following:

Have a look at the pcb.

(image by mmmonkey and dcemu)

The (original) blops of solder tend to come off the pcb. It looks like I am ripping apart the pcb itself - the wire I use then holds my blop of solder, combined with the original solder-blop and some pices of thin copper, that came off the pcb itself.

Once the original blob (and copper) is off the pcb I got no more change to get it back to the pcb, since there is no solder or copper left on the pcb at all.


What I am doing wrong?

Is my soldering iron to hot/harsh? Am I applying to much force to the wires? Why do the original blops tend to come off?

Please enlighten me.


Kind regards, and thanks for your help in advance,
ninn

What's the wattage of your soldering iron? More importantly, are you heating the wire or the solder? You probably already know this, but the trick is that you're supposed to heat the wire or the contact, and you're not supposed to apply the iron to the solder blob directly. If the solder is vaporizing or sticking to your iron, then you're doing it wrong.

Generally speaking:

Make sure you're using a soldering iron not a soldering gun. 

pre-tin your wires, coating them with a layer of solder before they get anywhere near the PCB.  It should be a very thin layer, not a blob, as if silver-plating it.

Lower the iron to the pad, it should melt the solder in about a second, slightly longer for larger blobs or blobs attached to GROUND 'cause those are attached to a lot of copper that sucks the heat away quickly.

Once the blob is liquid, lower the tinned wire to the blob.  Alternatively, put the wire on the blob and the iron on top of that.   They should both heat and flow into one mass in a second or two.

Leave the wire down, remove the iron.  Total time with an iron on the PCB should be less than four seconds (and closer to half that), or you're doing something pretty seriously wrong.  The longer you apply the heat, the more likely you are to have the important bits come away from the PCB.

If your iron is very low-watt (ie: 10W precision iron) then you're using the wrong tool.  It'll force you to heat for far longer than desired.

Thanks a lot for your hints, guys!

The basic idea is the correct one - pretinning and heating for just a few seconds ...

but it sounds like I am just using the wrong tool. My solder iron is old, and does not work very well. Sometimes it vaporizes the solder and the solder tends to stick on the iron.

Thanks for your help - i guess I will just look out for a new iron.

Hooray,
Ninn

Your third Dreamcast!? 

Your soldering iron VAPORIZED the solder? Hope you didn't breathe that! With the kind of iron you should be using for this kind of work, it should never get hot enough to vaporize solder... The iron temperature should be around 350° C. If you're looking to do regular modding work, might I suggest one of these. It's cheap, temperature controlled, fairly high quality, and works great. It's a huge step up from those cheap hardware store irons. (Kind of like the step up from composite to VGA. )

I just did mmmonkey's internal VGA mod yesterday and I can verify that it works great. Keep on trying! I hope you don't ruin any more Dreamcasts!

There's pretty much no chance you converted solder to vapour, more likely you're seeing the rosin core evaporating.  That's why soldering smells so good, it's not lead fumes, it's rosin.  =)

Yeah, that's what I was thinking, but I wasn't sure if that's what he was talking about. An iron that could vaporize solder would be pretty frightening... I know I have a glue gun that starts to vaporize glue sticks if you let it sit too long, and that's scary enough.

Yeah, it looks brownish ... could be rosin.

But I dont want to know excatly, i guess ... I just want to get a new soldering iron. 

Thanks for the link, I will try to get some money for a better iron next week. 

Thanks a lot,
ninn

try getting a stand for the iron, with a temperature control on it. that way you can keep upping the temp until its just hot enough to melt the solder. thats what i do and have never had this problem.