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Topic: Desoldering discussion split from: GridSeed 5-chip USB miner voltage mod (Read 1220 times)

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Activity: 84
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Actually you stand more chance of damaing your miner using a soldering iron - even 30w - than a hot air rework station. With a soldering iron you need to be very careful that you dont apply just a bit too much heat and lift the track off the board. Not gonna kill it little bit of green jumper wire can correct it easily. but it easily done. even wiht skill and experience. Done several in the past myself -years ago. Since i started using hot air ive never damaged a single piece or lifted a track. the hot air melts the solder and its not direct heat on the track. the componetents can take the heat. most SMDs are mounted with anything from 120,180 up to about 230 c. As long as the hot air isnt applied for more than about 10 mins youll be fine. And if after 10 minutes youve not attached it or removed give up your doing somethign wrong.

Either way it done carefully and properly you want damage it. but think the risk is greater using a soldering iron.

Forget it, it is bullshit. You have to be total retarded to lift the track with soldering iron(you have to keep it on the track for more than 5 minutes). 120...180 c used for pre-heating, the lead free solder(Sn-Ag) requires min. 220 c, normal Lead-Tin(67-33) required 210 C max.
Aint bullshit i left tracks in the paste when desoldering bits, normal things like com ports connections. getting to the last pin track goes. or you get a glob of solder still there and decide to go in for it again and track lifts away. seen it happen and its happened to me in the past, especaill when your pushed and trying to get it done for whatever reason. And considering your some of the  temperture for a soldering irons - not temperture conrolled ones of course, think a 30watt produces something like 220 c about 410 f. cant remember though.

Its easliy done especailly if your inexperienced in soldering. Note i said i done it ie past ref, ie years ago. learnt the hard way to allow the track to cool after so many desoldering points.
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Activity: 84
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[/quote]
i think it can be blowed away for sure if you use wrong size nozzle and apply too much air flow. specially cheapo stations may have problems on regulating air flow precisely. using a tape is a very good idea! just to be sure that something unnecessary isn't blowing away..

[/quote]
You hit the nail on the head there with cheapo station more than anything. a lot of cheap stations use a fan fro blowing the air (and cheapo fans too!), hot air dryer style. theese are great for heat shrink tubing, but not really for SMD even though there labeled and rated as for SMD rework. The better ones use a diagram system to push air out, some have a small fan as well but most of the air blowing is done via the diagpham. has an added advantage of not blowing contaminents onto the board as well.

Nozzle size is another key factor, along with distance and heat setting.

All i can say is its a tiny piece of tape. bit of fulx and paste. heat it slowly the flux will hold it the surface tension of the flux will keep it and the solder paste will pull it into postion. Ive never had a componet blown away.
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Activity: 84
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There is no point in going crazy with tiny SMD resistors and the hassles and expense of buying much less using a hot air station that if not used properly can destroy your miner!
A simple 30W soldering iron with a pencil tip will do the job perfectly. It will remove the old resistor chip and easily solder the new axial resistor in place without any risks to damaging other components. It takes a steady hand and experience to do it correctly in any case.

Actually you stand more chance of damaing your miner using a soldering iron - even 30w - than a hot air rework station. With a soldering iron you need to be very careful that you dont apply just a bit too much heat and lift the track off the board. Not gonna kill it little bit of green jumper wire can correct it easily. but it easily done. even wiht skill and experience. Done several in the past myself -years ago. Since i started using hot air ive never damaged a single piece or lifted a track. the hot air melts the solder and its not direct heat on the track. the componetents can take the heat. most SMDs are mounted with anything from 120,180 up to about 230 c. As long as the hot air isnt applied for more than about 10 mins youll be fine. And if after 10 minutes youve not attached it or removed give up your doing somethign wrong.

Either way it done carefully and properly you want damage it. but think the risk is greater using a soldering iron.

No, actually you don't! The chances of melting other solder connections and 'blowing' components off the card while trying to de-solder a single resistor with a hot air gun is far greater than using a pencil iron that only contacts the component you want to de-solder and solder back on the card. Also, a hot air gun heats up other components close to the one you're trying to work on and can overheat and damage / ruin components unnecessarily.
The evidence should be obvious to anyone trained and experienced in these techniques. Hot air guns are mostly for multi-pinned components like mirco-processor chips and other type of mult-pin chips. That's where hot air guns RULE over pencil irons!
Actually if you use the correct size nozzle and an opprate fan speed for your heat and distance and nozzle and youll heat up the componet and only componet required - without blowing it off the board.(Truthfully my smallest nozzle is a bit big for 0402 series smd telling me a soldering iron doesnt heat the tracks up or physically transfer heat to the componet come on dream on. Hoty air is for SMD any type of SMD, as anyone with experience in SMD in these techniques will tell you. Plus on hot air, if you want, you can reuse the compoent or put it back if it fails, try that after removing a resistor wiht a soldering iron, try to find your SMD in your blob of solder on the tip of the iron. With hot air you can swap out as many time as you want and reuse each piece. a soldering iron each piece is gone. Face it hot air rework is for SMD work - not saying you cant do it wiht a soldering iron, you can but your risks are greater
For smd hot air rework everytime

RIGHT TOOL FOR THE RIGHT JOB.

Done properly you wont blow compoents off or heat up surronding componets just with a hot air rework. Besides as stated hot air on the componets isnt going to damage them - never done a home DIY graphics card fix putting it in the oven about 120c to reheat and seat the contacts on the chips?? - not like the physical contact of a soldering iron can. And if you missplace it a bit and its heats up a neighbouring connection no problem remove the hot air and the solder will re solidify no problem componets wont even move - called surface tension, itll hold the compooent in place as long as you dont touch it. And FYI surface tension is the underlying factor of doing SMD hot air rework or even SMD mounting in the first place, the compoonets are postions and pulled into place using the surface tension of the molten solder. you should see it sometime its really quite amazing to watch.

Face it times have moved on. Theres more to electronics that a soldering iron even for a hobbyist. And seriously if your offering to do other people mods for them you want to consider getting a hot air rework, the reward and benfits and speed will pay for themselves, not to mention a more professional looking finish. And basic resistor mod with soldering iron ok, try the more advanced overclocking with a soldering iron. No chance youll completey destroy the board!

Anyway do what you want. this is done and dusted.
member
Activity: 107
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Actually you stand more chance of damaing your miner using a soldering iron - even 30w - than a hot air rework station. With a soldering iron you need to be very careful that you dont apply just a bit too much heat and lift the track off the board. Not gonna kill it little bit of green jumper wire can correct it easily. but it easily done. even wiht skill and experience. Done several in the past myself -years ago. Since i started using hot air ive never damaged a single piece or lifted a track. the hot air melts the solder and its not direct heat on the track. the componetents can take the heat. most SMDs are mounted with anything from 120,180 up to about 230 c. As long as the hot air isnt applied for more than about 10 mins youll be fine. And if after 10 minutes youve not attached it or removed give up your doing somethign wrong.

Either way it done carefully and properly you want damage it. but think the risk is greater using a soldering iron.

Forget it, it is bullshit. You have to be total retarded to lift the track with soldering iron(you have to keep it on the track for more than 5 minutes). 120...180 c used for pre-heating, the lead free solder(Sn-Ag) requires min. 220 c, normal Lead-Tin(67-33) required 210 C max.
sr. member
Activity: 378
Merit: 250



There is no point in going crazy with tiny SMD resistors and the hassles and expense of buying much less using a hot air station that if not used properly can destroy your miner!
A simple 30W soldering iron with a pencil tip will do the job perfectly. It will remove the old resistor chip and easily solder the new axial resistor in place without any risks to damaging other components. It takes a steady hand and experience to do it correctly in any case.

Actually you stand more chance of damaing your miner using a soldering iron - even 30w - than a hot air rework station. With a soldering iron you need to be very careful that you dont apply just a bit too much heat and lift the track off the board. Not gonna kill it little bit of green jumper wire can correct it easily. but it easily done. even wiht skill and experience. Done several in the past myself -years ago. Since i started using hot air ive never damaged a single piece or lifted a track. the hot air melts the solder and its not direct heat on the track. the componetents can take the heat. most SMDs are mounted with anything from 120,180 up to about 230 c. As long as the hot air isnt applied for more than about 10 mins youll be fine. And if after 10 minutes youve not attached it or removed give up your doing somethign wrong.

Either way it done carefully and properly you want damage it. but think the risk is greater using a soldering iron.

No, actually you don't! The chances of melting other solder connections and 'blowing' components off the card while trying to de-solder a single resistor with a hot air gun is far greater than using a pencil iron that only contacts the component you want to de-solder and solder back on the card. Also, a hot air gun heats up other components close to the one you're trying to work on and can overheat and damage / ruin components unnecessarily.
The evidence should be obvious to anyone trained and experienced in these techniques. Hot air guns are mostly for multi-pinned components like mirco-processor chips and other type of mult-pin chips. That's where hot air guns RULE over pencil irons!
member
Activity: 84
Merit: 10



There is no point in going crazy with tiny SMD resistors and the hassles and expense of buying much less using a hot air station that if not used properly can destroy your miner!
A simple 30W soldering iron with a pencil tip will do the job perfectly. It will remove the old resistor chip and easily solder the new axial resistor in place without any risks to damaging other components. It takes a steady hand and experience to do it correctly in any case.

Actually you stand more chance of damaing your miner using a soldering iron - even 30w - than a hot air rework station. With a soldering iron you need to be very careful that you dont apply just a bit too much heat and lift the track off the board. Not gonna kill it little bit of green jumper wire can correct it easily. but it easily done. even wiht skill and experience. Done several in the past myself -years ago. Since i started using hot air ive never damaged a single piece or lifted a track. the hot air melts the solder and its not direct heat on the track. the componetents can take the heat. most SMDs are mounted with anything from 120,180 up to about 230 c. As long as the hot air isnt applied for more than about 10 mins youll be fine. And if after 10 minutes youve not attached it or removed give up your doing somethign wrong.

Either way it done carefully and properly you want damage it. but think the risk is greater using a soldering iron.
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