Replace SMD USB Plug - Iron or Heat Gun? - Page 1
Forum section: electronics / beginners

author: FearTec
author_rank: Regular Contributor
timestamp: September 06, 2020, 09:36:14 am
content: I am debugging my sister in laws broken portable monitor (https://us.aoc.com/en/monitors/e1659fwu) that's not turning on.I have tracked this down to a broken ground pin on a USB "micro-b super speed pin" connector on the monitor side of the plug. The pins are shattered.I have a soldering iron with small tips (and can desolder with copper wick) but it won't fit under the smd plug.The 10x pins appear to be under the connector and may need a heat gun?Q1) Would an SMD heat gun be better?Q2) What is a good but cheap heat gun for smd repair or hand solder rework once in a blue moon? I have noticed ones on ebay with small air tops for $60, are they a bad idea?I am confident soldering (lead free) through-hole, Arduino shields, EBS32 feathers etc (with flux etc) but am a newbie. I love watching Dave/EEV Blog and Lewis Rossman repair videos.

author: FearTec
author_rank: Regular Contributor
timestamp: September 06, 2020, 09:40:26 am
content: Rear of the plus will be easy to remove

author: FearTec
author_rank: Regular Contributor
timestamp: September 06, 2020, 09:42:01 am
content: Rear of the plug[ Specified attachment is not available ]

author: FearTec
author_rank: Regular Contributor
timestamp: September 06, 2020, 09:43:18 am
content: Oops, I can't delete duplicate images

author: FearTec
author_rank: Regular Contributor
timestamp: September 06, 2020, 09:46:27 am
content: Is $67 for a "One Hung Low" as Dave says for a Chinese special Heat gun with small tips for SMD too cheap?https://www.ebay.com.au/itm/BK-858D-SMD-Brushless-Heat-Gun-Hot-Air-Rework-Soldering-Station-700W-220V-nh/143436382410?hash=item21657980ca:g:HTMAAOSwlHJdJWIA

author: Twoflower
author_rank: Frequent Contributor
timestamp: September 06, 2020, 10:04:05 am
content: I would carefully cut the grounding pins of the metal frame and remove them separately. Be careful not to put too much force onto the connector itself. Rip any pads of the surface mounted pins would complicate things. After the metal housing is removed you might be able to cut the plastic part in half (careful to not to cut the PCB surface).Edit: The 'signal' pins of the USB connector are clearly visible and not under the USB connector.Too small tips ain't very helpful as the very tip might not get hot enough. Still using an 1.2mm wide tip and soldering SMDs down to 0.65mm pitch. But I'm also not an expert thought.

author: FearTec
author_rank: Regular Contributor
timestamp: September 07, 2020, 05:51:50 am
content: I don't think I will cut anything, I'll buy a heat gun to pop off the SMD plug and maybe wick away the side pins with a soldering iron and wickAny affiliate links I can use that support Dave for a SMD Heat Gun?

author: tkamiya
author_rank: Super Contributor
timestamp: September 09, 2020, 04:05:04 am
content: Heat gun will likely melt plastic on USB socket. I've done that.Here's something I've learned from someone who does this kind of thing professionally. CHIP QUICK! Please just google search this name. What it is, is a special alloy (solder) that melts at very low temperature. Take this stuff and just flood the pins with soldering iron. It will stay liquid for very long time, and usually, whatever you are removing just floats off.Trick is, you must remove all of what remains very very well. Solder wick is the right tool here. Otherwise, when you re-attach a replacement, it will not have the strength of ordinary solder. Works wonder in SMD stuff.

author: Renate
author_rank: Super Contributor
timestamp: September 09, 2020, 11:44:19 am
content: Quote from: FearTec on September 07, 2020, 05:51:50 amI vote for a Dremel (or your favorite mini rotary tool).Chop the heck out of the connector, then the pins will drop of individually with just a touch of a soldering iron tip.Being as cruel as possible to the old component is being as kind as possible to the PCB.

author: kjr18
author_rank: Regular Contributor
timestamp: September 09, 2020, 12:41:33 pm
content: With dremel and cutting, chopping you risk ripping pads off, no matter how delicate you try.Just use heat gun, place kapton tape on things you want to stay on board, use heat gun from connectors side to heat both pins and metal frame, after you got it out, put some solder on pins, wick solder out, put new one and use soldering iron to solder first metal frame, then pins. If you happen to make some bridges while soldering, use wick to take those out. Connector will melt? Who cares, it's broken anyway.

author: FearTec
author_rank: Regular Contributor
timestamp: September 13, 2020, 12:17:23 am
content: Thanks, I purchased a heat gun and many nozzles and some 18mm 300c wide kapton tape. I will use copper braid to de solder the through hole pins. I'll try a small solder tip and braid to remove the data pins but they are hidden under the plug (my macro photography is deceiving). If the small solder tip does not work I'll use the kapton tape and heat gun.To put the new plug on i will use the heat gun and smd paste. I have 2 new plugs on the way in cause I stuff up the first try.Thanks for the advice

author: kjr18
author_rank: Regular Contributor
timestamp: September 16, 2020, 11:29:38 am
content: It's possible that this socket might be soldered to board not only by through hole pins but also big pads on board, just like that unpolulated chip in front of socket.

author: Refrigerator
author_rank: Super Contributor
timestamp: September 17, 2020, 08:52:20 am
content: Anything that gets the board hot is fine, i've been using the cheap 50€ hot air station for years and it's perfectly fine for removing these connectors.The ground anchors can be a fiddle to get moving, but it's mostly only a problem with the bigger type A connectors.For a connector like this i would apply heat directly to the metal shell and as soon as the ground anchors started moving i would direct just enough heat on the pins to lift the connector off.

author: FearTec
author_rank: Regular Contributor
timestamp: September 22, 2020, 04:48:33 am
content: Update1) Heat gun purchased and in my hands2) 2x Replacement USB connectors are on the way (https://au.element14.com/hirose-hrs/zx360d-b-10p-30/micro-usb-3-0-type-b-rcpt-smt/dp/2554977?st=usb%20connector,%20micro%20usb%20type%20b,%20usb%203.0,%20receptacle,%2010%20ways,%20surface%20mount,%20right%20angle)3) 2nd Hand donor plugs on hand4) New SMD solder and flux on handRepair Steps1) Test the data and grounding pins on the existing plug with a muiltimeter first. Second close inspecting of the entire circuit board2) Apply Kapton tale to sensitive areas of the monitor circuit board.3) De solder the dead USB plug the monitor circuit board (copper braid)4) Clean the pads and add flux5) Apply SMD solder paste to the data pins area (or skip if using a soldering iron)6) Make sure the new part fits and test the alignment (clamp down), make sure data pins align.7) Solder the new usb plug side retaining legs first with a soldering iron (small chisel bit)Add Kapton tape to the top of the new usb plug9) Solder the data pins with a heat gun or solder is using an iron10) Inspect11) Test each pin with a mustimeter and make sure they are not connected, Test through to the board.10) RepeatIf this does not work investigate a board swap or fix upstreamThe monitor may already be dead due to the 5v portion of the damaged plug connecting with a circuit board. But it’s worth a shot.

author: wraper
author_rank: Unknown
timestamp: September 22, 2020, 04:53:46 am
content: Quote from: Twoflower on September 06, 2020, 10:04:05 amIt's a sure way how to damage pcb. By the time you cut mounting pins, pins on the backside and pad under connector will be ripped off from PCB. Side cutters will create pushing force when separating the pins and there is no way for connector to give except being ripped off from PCB.

author: FearTec
author_rank: Regular Contributor
timestamp: September 22, 2020, 05:03:02 am
content: Yes no cutting will be done, just desoldering wick and a soldering iron if if need be heat gun.Many many hours of Louis Rossmann videos watched so I fell like a pro

author: FearTec
author_rank: Regular Contributor
timestamp: September 26, 2020, 06:03:51 am
content: Update I removed the usb micro b superspeed plug with a heat gun, I pulled a data (pin 9) pad though. The soldering iron method did not work.

author: FearTec
author_rank: Regular Contributor
timestamp: September 26, 2020, 06:06:16 am
content: After I connect the 9 pins to the OK pads I will bridge a wire downstream to the board with a wire from a solid core ethernet cable (cat 6 oxygen free copper wire)?

author: FearTec
author_rank: Regular Contributor
timestamp: September 26, 2020, 06:08:49 am
content: I tested neighbouring pin 10 and followed the trace and it does connect to the exposed (test?) solder bump.

author: FearTec
author_rank: Regular Contributor
timestamp: September 26, 2020, 06:10:14 am
content: I did not take a photo but I did cover the board with Kapton tape before applying heat from the heat gun.

author: FearTec
author_rank: Regular Contributor
timestamp: September 26, 2020, 06:37:46 am
content: Any tips on what insulated wire to use to bridge a USB data line about 12mm across the circuit board

author: Siwastaja
author_rank: Super Contributor
timestamp: September 26, 2020, 07:21:58 am
content: Quote from: FearTec on September 26, 2020, 06:37:46 amSmallest you can find. Wire ripped off a CAT5(e)/CAT6 cable is OK, a bit on a thick side but usable.Try to follow the original route so that it runs over the original ground plane. You can glue it down with cyanoacrylate after soldering.Impedance mismatch likely won't cause issues this being such short trace, and I'm assuming this isn't USB3.

author: Refrigerator
author_rank: Super Contributor
timestamp: September 26, 2020, 12:52:56 pm
content: If you want thin wire then small 12V/5V relays are great because the wire there is so thin you can barely see it. But from my experience any wire will work as long as it's thin. I've even made short SATA cables with some random wire i found and it worked fine.Luckily you have an exposed pad right next to the connector so it will be easy to run a jumper once you solder the new connector in.Quote from: Siwastaja on September 26, 2020, 07:21:58 amIt's a wide port so it's a 3.0 or SS, but it can always default to 2.0.

author: Kasper
author_rank: Frequent Contributor
timestamp: September 26, 2020, 05:49:16 pm
content: Quote from: FearTec on September 26, 2020, 06:37:46 am30 AWG solid core wire is what I always use for that kind of thing.This may be overkill but if you struggle to solder it, try tacking it down with tape first. Make it stay where you want it before you solder. Bend it beyond the place you want it then pull back and place it where you want it, so the elasticity of the wire pushes it into the joint. Then apply flux and solder.You can also get pad replacement kit which is foil with glue on one side but 30 AWG wire is probably better for this.

author: FearTec
author_rank: Regular Contributor
timestamp: September 28, 2020, 11:49:16 pm
content: Thanks for the wire adviceI found on eBay a replacement (dead screen) monitor (same model and only 6 month difference between manufacturer) that I could steal a working circuit board from.If the replacement monitor is no good for salvaging parts (different revision monitor) I will return to repairing this board.There are loads of pad and trace repair videos on YouTube

author: FearTec
author_rank: Regular Contributor
timestamp: October 03, 2020, 01:07:01 am
content: Update I found a dead monitor on ebay that had the newer USB 3 plug not the micro USB 3 plug.I swapped the USB on daughter board and left the cpu board. The monitor is working and my duster inlaw is happy.Ill try and repair the trace on the spare board and attach the new smd plug for practice

author: FearTec
author_rank: Regular Contributor
timestamp: October 03, 2020, 01:10:36 am
content: New plug

author: FearTec
author_rank: Regular Contributor
timestamp: October 03, 2020, 01:18:13 am
content: Monitor working