Removing/replacing two SMD chips - Page 1
Forum section: electronics / repair

author: akis
author_rank: Frequent Contributor
timestamp: March 13, 2021, 08:31:51 pm
content: I would like to attempt to remove and replace two SMD chips from a burned out laptop motherboard. I have no specialist tools but I have looked to see what exists and have foundhttps://uk.farnell.com/chip-quik/smd1/removal-kit-smd/dp/1850214which I am not sure what it is. I attach a photo of the two ICs I need to remove, marked with yellow dots. For sizing, the two white empty pads next to those chips are about 7mm x 7mm.

author: mon2
author_rank: Frequent Contributor
timestamp: March 13, 2021, 08:50:17 pm
content: Hi. Sorry but the referenced kit will not work for this SMD component.Please see here to note the BOTTOM side pads which are also soldered onto the PCB.https://www.aliexpress.com/item/1005001993841513.html?spm=a2g0o.search0302.0.0.1d297bf8pbAupA&algo_pvid=5606bd26-e915-488c-affe-215ec62a7c77&algo_expid=5606bd26-e915-488c-affe-215ec62a7c77-2&btsid=0b0a556416156680245988382e41c7&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_What you will need are:1) sticky solder flux from Amtech of the many clones "559" series.https://www.aliexpress.com/item/32788246494.html?spm=a2g0o.productlist.0.0.703d9953xhLyV5&algo_pvid=d96cbe44-24b1-40c6-b822-bcef4e4f71ae&algo_expid=d96cbe44-24b1-40c6-b822-bcef4e4f71ae-0&btsid=0bb0624216156682595382329ee13a&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_2) desoldering braid to clean off the solder once the part is removedhttps://www.aliexpress.com/item/32958719300.html?spm=a2g0o.productlist.0.0.10a75552TD9ciG&algo_pvid=8c6114e2-6e72-4822-b2e6-818026a05544&algo_expid=8c6114e2-6e72-4822-b2e6-818026a05544-0&btsid=0b0a557016156684728511521e1942&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_3) hot air gun + tweezers. You may be able to find the same on your local Amazon at varying prices.https://www.aliexpress.com/item/1005001418386489.html?spm=a2g0o.productlist.0.0.55e011ea6deaeN&algo_pvid=91fa7187-61a1-40a6-b63d-f011a61f1eca&algo_expid=91fa7187-61a1-40a6-b63d-f011a61f1eca-1&btsid=0bb0623b16156685074562557eca0a&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_Apply the flux ontop of the mosfet you wish to remove and apply the heat gun at 300+ degrees. The hot air will melt the flux and start to melt the underside solder. Gently nudge the mosfet during this process. Once hot enough, the mosfet will come off the PCB just fine - remove with your tweezers. Avoid touching the component while hot.Do note how the part is soldered to replace with another.Apply aluminum foil on other nearby parts to keep the heat from disturbing the other surrounding components. You wish to only melt these mosfets and then remove and replace.If you are not interested in the above investments, take to a local qualified cell phone or macbook repair shop. Be sure to ask if they are comfortable with SMD part replacements. They should be able to perform this task in 20-30 minutes.The mosfets are from AON and see plenty on Aliexpress.

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 09:06:31 am
content: bravo! all clear.