Advice For Heat Gunning.
Posted 10 June 2010 - 10:27 PM
I have this heat gun:
There are 2 temperature settings. First is at 750° F/ 400° C. Second is at 1000° F / 540° C.
I have read that the capacitors blow at around 210° F/ 100° C.
And Lead-Free solder melts at around 460° F/ 240° C. (Are these temperatures accurate?)
This is my plan:
Take out motherboard. Lie it down on flat surface, make sure it does not move when heat gunning. Take off heat sink and clean old thermal paste. (it dose not need to be standing, im assuming)
I am not going to put tak-putty or plastic or aluminum, how can you tell if its gana blow or not if its wrapped up? (is this a good decision? what do you recommend? Im not gana be stupid and let it burn if i see it smoking or anything im going to stop.)
While heat gunning i am not going to be moving the mother board also i am never going to stop moving the heat gun i will move it in circles so it will not burn.
Apply Flux, Rosin free’ and ‘No Clean. I used "KESTER 951 NO CLEAN SOLDER FLUX" from ebay. (Is this the correct flux to use? In your opinion what is the best flux?)
Using the Dropper insert under gpu. I used this video on youtube.
Now i need to know how long the heat gun should be on the board. Here are different settings i have found on various tutorials and forum post. Please give me your opinion which is the best.
A. Turn on Heatgun, Heat for 3-4 mins on Top Side.
Turn the motherboard 90 degrees. Repeat only if desired. Use same timing.
Turn the motherboard over. Repeat. Use same timing.
Wait 45 mins between each turning of motherboard for motherboard to cool.
B. Turn on Heatgun setting one, 500°F/260°C, Warm up for 1 min on Top Side. Hold heat gun 4 inchs from motherboard. (Apx. Fist Hight)
Set Heatgun to setting two, 1000°F/540°C, Heat for 3 mins.
Turn Heatgun to setting one, 500°F/260°C, Gradually increase heatguns height for 2-3 mins. Gradually lowering the motherboards temperature.
C. Turn on Heatgun setting one, 180°F-250°F/80°C-120ºC, Warm up for 1 min on Top Side. Hold heat gun 6 inchs from mother board.
Set Heatgun to setting two, 1100°F/600°C, Heat for 4 mins.
Set Heatgun to setting one, 180°F-250°F/80°C-120ºC, Gradually increase heatguns height for 1-2 mins. Gradually lowering the motherboards temperature.
Let cool for 45 mins. Turn Motherboard over and repeat using same timings.
D. Turn on Heatgun setting one, Heat for 2-3 mins untill flux has evaporated.
Turn motherboard over and heat for 1 min.
Now my questions are:
1. What parts on the motherboard do i need to use the heat gun on? GPU, CPU, HANA, RAM etc.
2. Considering my Heatgun temperatures, what timing and distance away from motherboard do you recommend?
3. Should I heatgun both front and back of the motherboard or just one side, if so which side?
4. If i heatgun both sides do i need to reapply flux?
5. How long does it take for the motherboard to cool fully?
Any other tips, hints or precautions please tell. Feel free to PM me if you like.
Posted 10 June 2010 - 11:49 PM
Edited by FLUFFYbunny27, 10 June 2010 - 11:49 PM.
Posted 11 June 2010 - 12:11 AM
You do not want to heat one side up and then flip it over. This is a big no no and it's pointless to wait for the top to cool down and then do the bottom side. The point of heating the bottom is to keep the board heated while reflowing the top side. If you do one side at a time you are doing nothing, the board will just then flex on you(may not happen right away but it will).
If you really want to try and attempt the heat gun method buy a griddle like the video above and just protect the components around the gpu and if it starts to smoke or you smell something pull away.
Don't be surprised if you fail as this will only do more damage than good. Even if it boots and works, it's only a "fix". Be aware that failed heat gun attempts will cause the solder to bridge and thus resulting in a Reball.
Posted 11 June 2010 - 12:14 AM
I've been doing this for years and tried everything under the sun... best thing you can do is make some kind of frame to bolt the board on so it doesn't warp. Then preheat board in oven to ~250F unless you have another controlled method from heating from underneath. After preheated gun only the GPU, time will depend on gun but 6 Min with 480F gun works for from about 1" away and I do have a aluminum foil frame built around the sides of the GPU to contain the gun heat, frame walls slightly less than 1". It would be highly recomended to first test the gun on a dead parts board to find out how long it takes to lift and popcorn (destroy) the GPU.
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users