115 lines
5.1 KiB
Markdown
115 lines
5.1 KiB
Markdown
---
|
|
title: "ThinkPad USB Port Fix"
|
|
date: 2019-02-28
|
|
lastmod: 2019-02-28
|
|
categories: ["Blog"]
|
|
tags: ["electronics"]
|
|
---
|
|
From the moment that I first had my (_used_) ThinkPad X220, the bottom-right USB
|
|
port nearest to the SD card reader had been broken. The pad (_or bolster_) was
|
|
missing, along with 3 out of 4 pins having been completely broken off. Needless
|
|
to say this required fixing.
|
|
|
|
<!--more-->
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04781.jpg" sub="Final result" >}}
|
|
|
|
|
|
# Damage Assessment
|
|
The first step was to look at the PCB to assess how this could be, if at all,
|
|
replaced. From the outside you could see the damage done. Note the single
|
|
pin left and lack of the inner pad (_bolster?_).
|
|
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04722.jpg" sub="One pin remains" >}}
|
|
|
|
|
|
# Measure Twice
|
|
Next on the list: measurements. To find a suitable replacement receptacle, I
|
|
needed to have the relevant dimensions in comparing to receptacle part drawings
|
|
of those available for sale.
|
|
|
|
{{< thumbgallery >}}
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04714.jpg" >}}
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04718.jpg" >}}
|
|
{{< /thumbgallery >}}
|
|
|
|
Using generic, non-branded digital calipers I was able to get the following
|
|
**approximate** dimensions:
|
|
|
|
| Description | Value |
|
|
|:-----------------------------|---------:|
|
|
| Total Length | _14.7mm_ |
|
|
| Total Width | _13.2mm_ |
|
|
| Pad Spacing (_along length_) | _9.1mm_ |
|
|
| Pad Spacing (_along width_) | _15.4mm_ |
|
|
| Pad Width | _1.9mm_ |
|
|
<center><sub>Fig. 1</sub></center>
|
|
|
|
|
|
# Shopping with Purpose
|
|
Using the value above, I was able to track down a USB receptacle[^1] on
|
|
Digi-Key[^2] that matched my requirements very, _very_
|
|
closely.
|
|
|
|
## Resounding Comparison
|
|
Keep in mind the measured values were an eyeball approximation with a low cost,
|
|
unbranded digital caliper. Those values are nearly spot-on.
|
|
|
|
| Description | Measured | Part | Difference |
|
|
|:-----------------------------|---------:|----------:|:-----------:|
|
|
| Total Length | _14.7mm_ | _14.00mm_ | _**+.7mm**_ |
|
|
| Total Width | _13.2mm_ | _13.10mm_ | _**+.1mm**_ |
|
|
| Pad Spacing (_along length_) | _9.1mm_ | _9.1mm_ | **---** |
|
|
| Pad Spacing (_along width_) | _15.4mm_ | _15.7mm_ | _**-.3mm**_ |
|
|
| Pad Width | _1.9mm_ | _2.30mm_ | _**-.4mm**_ |
|
|
<center><sub>Fig. 2</sub></center>
|
|
|
|
The part was ordered, and arrived quickly at my doorstep. Stacked on top of each
|
|
other the two receptacles matched up just as I had hoped.. **Fantastic!**
|
|
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04773.jpg" >}}
|
|
|
|
# It's not over yet
|
|
Initial attempts at desoldering the existing (_broken_) receptacle proved
|
|
futile. Even with liberal application of flux, high soldering iron temperatures
|
|
well beyond typical soldering temperatures[^3], the solder would not flow and
|
|
the part would not budge. However, I was able to remove the surface mount pads
|
|
though this proved useless later on.
|
|
|
|
I quickly realized it did not matter to take care in not damaging a broken part
|
|
for removal. Grabbing a nearby set of flush cutters I was able to easily remove
|
|
the broken receptacle! _However_, this wasn't **yet** the end.
|
|
|
|
The leftover cutoff pins still attached to the PCB proved impossible to
|
|
remove. I was able to get all through-hole header pins removed but one. After
|
|
having spent about half an hour on it with tweezers, solder wick, a solder
|
|
sucker (_desoldering pump_), and flush cutters, I gave up.
|
|
|
|
# Throwing in the Towel
|
|
It turned out the only way to attach the replacement was to modify the new part
|
|
to fit -- _luckily I had ordered two replacements as I broke the first one in
|
|
the modification "process"_. Cutting and bending the pins, I was able to get it
|
|
soldered on (poorly). There wasn't much wiggle room for cleaning up the
|
|
bodged-in replacement; this will have to do.
|
|
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04774.jpg" >}}
|
|
|
|
The part was essentially soldered as a wholly surface mount part, which it is
|
|
not. This could have future issues due to a lack of solder-terminated strain
|
|
relief in connecting and disconnecting USB devices. In hindsight, I may have
|
|
been able to bend the flat pads towards the entry of the receptacle down to
|
|
attempt to solder them to the surface mount pads.
|
|
|
|
# All the King's horses, all the King's men
|
|
Alas, it was time to put the laptop back together. To my dismay there were
|
|
further problems. Due to the modification and forced fitment of the replacement,
|
|
the USB receptacle was sticking out too far off of the PCB preventing the
|
|
motherboard from correctly fitting. This was quickly solved by using a Dremel
|
|
with a low-grit sanding drum and removing material off of the receptacle. The
|
|
result was acceptable, and provided a tight fitment into the laptop case.
|
|
|
|
{{< thumb src="/img/thinkpad-usb-fix/DSC04775.jpg" sub="End of the journey" >}}
|
|
|
|
[^1]: [Molex Part No. 482580002](https://www.molex.com/molex/products/datasheet.jsp?part=active/0482580002_IO_CONNECTORS.xml&channel=Products)
|
|
[^2]: [Digi-Key Part No. WM7087CT-ND](https://www.digikey.com/products/en?keywords=WM7087CT-ND)
|
|
[^3]: Typical soldering temperatures are around 315-370°C (_600-700°F_)
|