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From Wikipedia:

Alloys commonly used for electrical soldering are 60/40 Sn-Pb, which melts at 188 °C (370 °F), and 63/37 Sn-Pb used principally in electrical/electronic work. 63/37 is a eutectic alloy of these metals, which: has the lowest melting point (183 °C or 361 °F)

Having previously successful done a 'reflow' of a computer Graphics Card in a home oven in my only attempt of this kind, I am now considering doing the same for a motherboard which, while still functioning (occasionally, it will fail to start up or black screen mid use, and yes, it is the motherboard).

However with my motherboard containing a wider array of PCB components like ROMs etc and a fair bit of 'plastic' composites like ram slots (they have hundreds of traces so not practical to solder them all of in order to remove) I am more skeptical this time around.

My assumption is being PCB components that these surely adhere to some sort of temperature resistance requirements? However at 170-180 °C that I would be baking at I'm really unsure if things like capacitors, vrm's Vcontrollers and the 'plastic' bits like ram and PCI slots could handle the heat.

I'm hoping the community here can help me out on this one, as searching online mostly churns out baking laptop motherboards which lack these 'plastic' bits.

The board in question looks like this:

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Hmm... doing it in a domestic home oven is totally uncontrolled. It may also get you anally bruised from unexpected interactions with your domestic partner.

Reflow ovens for production boards typically use either radiant heat or what is effectively a giant heat gun. Heat is only applied over a controlled and timed temperature sequence profile and the boards are cooled quickly. I would be concerned you would need to have the board in the oven for far too long. Furthermore, reflow is done in a non-oxygen gas to prevent oxidation.

Some components probably wont mind too much, but others like electrolytic capacitors will boil off, and yes plastics can melt.

Reflow Oven Types

Reflow Soldering

And it looks from your question that you effectively want to "touch-up" an existing soldered board.

That is not what Reflow-Soldering means, and I would consider that a bad idea in general.

A considerable amount of oxidation has accumulated on the joins and pins since the board was originally manufactured, and you have no way to add flux. There will also be considerable other contaminants, dust, and oils, that have accumulated on the board too.

You are far more likely to find the solder balling up into beads and breaking connections than miraculously fixing some suspected loose connection.

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    \$\begingroup\$ I must respectfully disagree with this "doing itbin a home oven is totally uncontrolled". While you may (in general) be right, there are excellent reflow oven DIY kits that use temperature controllers and whose reflow profile can be calibrated with surprisingly good accuracy. \$\endgroup\$
    – Enric Blanco
    Commented Mar 2, 2017 at 9:32
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    \$\begingroup\$ Good to know @EnricBlanco, though I was under the impression his "Home Oven" is the same one his wife cooks the Sunday roast in. I can't see him having bought one of those kits to do one graphics card. but I will change the text a little since I was unaware there were such kits. \$\endgroup\$
    – Trevor_G
    Commented Mar 2, 2017 at 15:57

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