What is a Reflow?
The term ‘reflow’ describes a process of briefly melting (reflowing) the solder on an electrical circuit board.
Why would you perform a Reflow on a laptop?
The solder used in laptop motherboards tends to degrade over time,  becoming brittle and weak. It can change from being a solid block of  solder into more of a honeycomb structure. This weaker solder joint can  fracture causing tiny broken connections in the circuit, invisible to  the naked eye. The idea behind performing a reflow is that it melts the  solder, allowing it to form a solid block again and joining up the  electrical circuit.
When would you perform a Reflow?
There are a number of scenarios where performing a reflow can be  successful. A typical example is a laptop motherboard which is receiving  power, lights come on to confirm this, but it just won’t power up. It  is possible that a crucial connection has been broken by weakened  solder.
Another common example is a laptop that will appear to power up, but  there is no graphics output to the LCD panel or to an external screen.  In this case, it is likely that there is a broken solder joint around  the graphics chip (GPU).
A reflow is a method of last resort. In other words, you would only  ever try this on a motherboard that was so completely faulty that it  would otherwise need to be replaced. If performed incorrectly, a reflow  can damage your motherboard even further. But on the other hand, if the  motherboard is broken anyway, and would otherwise be replaced, then  performing a reflow won’t make the problem any worse.
How do you perform a Reflow?
There are expensive infra-red reflow stations which can be purchased  which will do this job for you. However, if you are on a budget, the  easiest method of performing a reflow is to bake the laptop motherboard  in a household oven.
This might sound a bit crazy, baking your laptop in an oven, but if  performed correctly, it can achieve the same end result, remaking the  solder connections which may have been broken.
It is very important that the motherboard is completely stripped down  before attempting this procedure. Remove the CPU, heatsink & fan,  RAM, BIOS battery, wires, speakers, stickers, plastic sticky guards,  foam spacers, absolutely everything that can be removed from the  motherboard.
Then preheat your household oven to approximately 200°C or 385°F. If  your oven does not have a digital temperature display, perhaps use an  internal oven thermometer to make sure the oven is in the right  temperature range.
Roll up some kitchen foil into balls, between half an inch and an  inch wide, and place them on a baking tray. Place your motherboard, with  CPU socket and GPU facing upwards, on top of the foil balls. It is a  good idea to wrap additional foil around the more sensitive parts of the  motherboard, like areas where there are capacitors and the CPU socket.  If the reflow is being performed because of a faulty graphics chip (GPU)  then perhaps wrap the rest of the motherboard in foil to protect it,  leaving just the GPU exposed on both the top and bottom of the  motherboard.
Then place the baking tray with the motherboard on it into the  preheated oven. Every few minutes, have a look through the oven door  (without opening it) making sure there is no smoke or flames visible.  This is unlikely to occur, but can happen if stickers were left on the  motherboard.
After 8 minutes, turn the oven off and open the oven door. Do not  remove the motherboard from the oven at this stage, it could be very hot  and it is a better idea to allow it to cool down gradually. Make sure  your kitchen is well ventilated at this stage, turn on the extractor fan  to full power and/or open an outside door. This will take away any  fumes. I recommend that you leave the kitchen while any fumes are still  present.
After 20 minutes to half an hour, remove the motherboard from the  oven and begin rebuilding your laptop. If all has gone well, it will  boot up and the problem will be fixed. If the problem remains, you could  try the procedure again, leaving it in the oven for a couple of minutes  longer.
After performing a reflow in an oven, I recommend cleaning the oven  thoroughly, then turn it on and allow any fumes that may have built up  to be completely removed, especially before cooking food in the oven  again.
How long will a Reflowed motherboard last?
It is impossible to say for certain how long a repaired motherboard  will last. It may be a few weeks or a year, there is no way to know for  certain. The problem with the solder fracturing does tend to come back  again eventually though. However this technique might at least get your  laptop running again for a while, long enough perhaps to save up for a  new laptop.
Video of a Motherboard Reflow
Here is a quick YouTube video I came across of someone performing a  motherboard reflow in a household oven. It doesn’t cover all the points I  describe here but it shows the basic principle.
Disclaimer:
Putting your laptop in a household oven is dangerous and is a method of  last resort when fixing a fault. This method of performing a reflow is  well documented across various sites on the internet, and although many  people have had success with it, it may not work in every case. We will  not be held liable for any damage you cause to your motherboard, to your  oven or to any person or property as a result of attempting this  procedure.
Thursday, 25 November 2010
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