Replacing 0403 SMD inductance - advice needed - Page 1
Forum section: electronics / repair

author: e-pirate
author_rank: Regular Contributor
timestamp: August 18, 2023, 08:57:33 pm
content: Hi folks.Some time ago I bought a "new old stock" ASUS Q87T motherboard for my home server. The board itself is fine and work well 24/7 with the exception of 0403 SMD 4.7 uH inductance. It was somehow damaged that (I think) causes Intel I210 it is related to not to start after a cold reboot in like 1 of 5 times. I would like to replace the inductance but afraid of disturbing neighbors, especially two 0201? caps to the bottom right of the inductor. I have a cheapo Chinese hot air reflow station on hand and can try to do this myself, but need some advises on air temperature and flow and, what is more important, how to protect nearby caps from be desoldered and blown away. Unfortunately, even having many good equipment I've been out of this hobby for a decade or so and therefore missing experience. Some youtube videos showing how to do this will be valuable as well.Thank you.

author: ataradov
author_rank: Super Contributor
timestamp: August 18, 2023, 09:15:34 pm
content: Lowest possible flow + higher than really needed temperature (I usually set 360-400 C). You can regulate the actual temperature by the distance from the nozzle.Inductors like this are one of the easier components to remove and place. And the lowest flow should not blow away nearby components, so no special protection is needed. But they are likely to reflow, so be careful when you are removing or placing the inductor.

author: Shonky
author_rank: Frequent Contributor
timestamp: August 18, 2023, 09:17:44 pm
content: Just use some kapton tape as well to both insulate and hold in place?

author: e-pirate
author_rank: Regular Contributor
timestamp: August 21, 2023, 06:05:23 pm
content: Yap, I have kapton tape from AE as well, bet never used it and already forgot I have one.Any advice on distance rage to keep nozzle from the PCB surface? Like.. 3-4 cm or less?

author: ataradov
author_rank: Super Contributor
timestamp: August 21, 2023, 06:13:29 pm
content: It depends on the hot air station and the nozzle. It is best to practice on some board you don't care about.But generally - as close as necessary to get the component hot enough. 3-4 cm sounds right about right.

author: e-pirate
author_rank: Regular Contributor
timestamp: August 21, 2023, 06:57:43 pm
content: Would you recommend reflowing new component with hot airl, or solder it using regular iron (I have a thermocontrolled station as well)?

author: ataradov
author_rank: Super Contributor
timestamp: August 21, 2023, 07:48:54 pm
content: For the inductor, I would personally reflow it using hot air. Inductors are annoying to solder with soldering iron and they generally work with hot air really well.

author: e-pirate
author_rank: Regular Contributor
timestamp: August 21, 2023, 08:37:38 pm
content: Thank you very much. I will get some of dead mother boards from one of our data centers to practice on and try to reflow this broken little puppy. Prior I will, probably, get a good hot air station as my old one is kinky and buggy as hell even it does the business. Got the job - get the good tool.

author: e-pirate
author_rank: Regular Contributor
timestamp: August 22, 2023, 10:27:13 pm
content: Scored original Quick 861DW. This repair just gave an excuse to buy another piece of equipment. Will test this 1kW beast on dead mobos next week.