Category: Gadgets

Wiistar HDMI Audio Extractor teardown (WS-E11B)

Back in 2020 I moved to a Roku Premiere as my primary streaming device. As my audio gear is older (pre-HDMI) I required something to split out the audio from the HDMI signal and the Wiistar HDMI Audio Extractor was a good fit.

At the time I mentioned that the device was a little suspicious, but it worked and kept working just fine for some time. After a year of trouble free operation, I did have a couple of times when the box would give up and pulling the power and rebooting it seemed to fix things. Stuff happens, no problem.

More recently it’s been acting up a lot. Blanking out, then coming back or not. Tapping or banging on the case seems to help ‘fix’ things temporarily. It appears that there is something not quite right with the power connection. This meant it was time to take things apart!

There is a horizontal seam on both sides of the device, you can see it right by the mini-USB connection and the switch. By pressing with a knife blade on this seam, I was able to un-snap the sides. This took a little doing, but was pretty easy. Some gentle wiggling freed the circuit board from the snap case.

No surprises here. It’s a single chip solution, likely decode HDMI, re-encode HDMI. There is likely a small audio amplifier circuit here to feed the 3.5mm jack. It’s pretty amazing that you can get something like this for the price.

The USB-mini power jack seems to be well affixed to the circuit board (no bad joints). I inspected the cable as well, and it looks to be a power only cable – only two pins on the plug. I tried adjusting the connector fit a little which might help my power problem (and I could have done from the outside of the case).

Then I took a closer look at that one chip..

Yup, that’s a blank, unbranded chip. I’m guessing this is a chip that failed QC and was discarded or sold off as seconds. Bunnie wrote about counterfeit chips which will give you an idea of how this chip may have ended up being used. In this case, they aren’t even trying to fake the chip – they just are trying to use one that was cheaper.

Well – it was interesting to open it up which turned out to be easy. I may have improved the power connection, but first try and it’s not working. Meanwhile I’ve ordered an AmazonBasics HDMI audio extractor as a replacement. The AmazonBasics device has a lot of (mostly) positive reviews. There is a youtube video teardown which while it’s terrible, does give a peek inside. There seems to be QC stickers on the circuit board, and the underside of the case appears to have FCC logos etc.

It’s likely a very similar solution, also needing a 5V 1A power supply. The pictures show you powering it from a laptop USB port, which is only going to provide 500mA – so there is some suspicious stuff going on here too with the marketing. Also, I suspect based on the comments it accepts up to 4k input, but can only output 1080p – which is fine for my needs.

Lint – the unseen foe

I’ve seen this a few times and it’s always surprised me until I’ve figured it out. Hopefully this brief post helps someone else one day.

Years ago a friend of mine had me over to help take his phone apart. The headphone jack had stopped being reliable (yeah, way back in the day when it was normal for you to plug in headphones). We had fun taking the phone apart, but in the end it turned out that the headphone jack was jammed full of pocket lint. Yup. Some careful digging with a pin and tweezers and we cleared out an alarming amount of lint that had jammed up the port. This fully restored the headphone jack function.

One of my kids had the same thing happen to them. Janky headphone jack, and yup – the bottom was stuffed full with pocket lint. Just be very careful poking around in the port. It’s not very big and you can mess stuff up. Lint is soft and will come out with some gently coaxing.

Lately my ~1.5yr old Pixel 4a had stopped reliably charging. The USB-C cable would fit in fine, but not stay put. It would also pop out very easily. This morning after another failed to charge overnight incident I again inspected the USB-C port. It looked fine. Probing very gently with a pin, it soon became obvious there was some lint in there. Then I pulled out more and more.. an alarming amount. There was a lot of lint. Now I can look into the port and see the shiny plastic bottom, not a dark matted blackness. The USB-C cable seats nice and deeply and doesn’t pop out easily.

Given phones probably live a good percentage of their lives in your pocket, this isn’t a surprising outcome. Still – cleaning out lint wasn’t even close to the first thing I thought of doing in any of these cases. I’d even checked what my warranty and repair options were. The fix was 2 minutes of careful work.

Samsung Galaxy S7 Battery Swap

Sure, the Samsung S7 is a 6 year old phone at this point – but it’s perfect for my son who’s in grade 7 and doesn’t really need a phone. The other day it stopped turning on – when you plugged it in, it would indicate the battery was at 100%. I could even get it to power on while plugged in, but removing the USB power would result in an immediate black screen as it powered off hard.

I sort of dreaded opening this phone up because it’s one of the ones that is glued shut. I was pleasantly surprised, as a little heating with the heat gun and the all metal back came up pretty easily using a suction cup. After that there were some phillips screws to remove and I was able to see the battery.

It was clear there was a problem here – the connector should be squared up with the rest of the circuit board. If you look closely – you can see that the battery has also shifted down significantly within the phone, nearly 2mm.

Taking a close look at the cable – you can see the connector is a little busted up despite my photo being a bit out of focus.

I attempted to reconnect the cable, but soon found out that the connector was badly damaged and it snapped off the cable completely.

Oh well. Off to search up buying a new battery for this phone. A quick look around and it seems there are lots of choices – some as low as $16 (eBay), and the normal crazy mark-up ones at $60-$90. I opted for one of the Chinese made knock off brands off of Amazon that came with tools (junk) and the adhesive to re-attach the back. It also claimed to be 3300 mAh vs the stock 3000. It was at a slight premium vs. eBay, but only a couple of bucks and the reviews were good. Worth the $25 and it shipped to me the next day.

My pricing logic for stuff like this is to avoid the cheapest prices – these are often very cheap for a reason. There is a step up from the cheapest where you’re going to get basically the same part up to the next price plateau – if you can discern the price notches you can basically buy at certain quality levels. The danger with all of these is that lots of unethical sellers will slap OEM labels on parts that are not, so often paying a high premium is not buying quality at all. It’s always a gamble which is frustrating.

The battery I’m replacing was already previously replaced. I think this is why the battery didn’t fit very well in the phone.  The poor fit is likely what resulted in it breaking off (when the phone was dropped, probably multiple times if I know my son). If you fit the broken battery into the compartment properly there is a significant gap at the bottom.

Again, this is nearly 2mm gap. The OEM battery is tape/glued in – but I suspect it also fit much more snugly in the space. If you are replacing a battery – consider if it will slide around and either tape – or pad it – to avoid the battery moving. I know that I’ve done battery swaps and left a gap in the past – I probably won’t in the future.

The new battery fits like a glove. Top to bottom, almost no space to move around. So I didn’t bother taping it in place, I’m pretty confident it’ll stay put.

While I’m not a fan of glued shut phones – I did use adhesive to re-seal the phone. Hopefully I won’t have to go back in at all. In a couple of years this phone will basically be too old to use. While it’s still running stock firmware, it does appear that there is an unofficial but current LineageOS build for it.

The S7 got a 3/10 score for repairability – but it wasn’t really that bad to get at the battery. The places where it got hit on the score was replacing some of the other components – I’ve certainly had more than 1 USB charge port go bad, and gluing that to the screen seems like a really bad idea. There really needs to be a better trade of for waterproofing and repairability.