Hacking an overheating HDMI to VGA converter

This is the sixth post in my attempt to start a blogging habit.

wpid-wp-1446231315483.jpegWhen you mail order something really cheap from China, you must prepare to make compromises, or even some modifications. That was the case with this HDMI to VGA converter as well.

I got it as a shot in the dark, as I didn’t know if my laptop could actually drive two monitors in the same time. So I didn’t want to spend too much money on it, I got the cheapest possible model for about $3.

After it arrived, initially I thought the converter was faulty, when after just about 20 seconds, the monitor started flickering and then lost the image. Since it always worked for a while after plugging in, then lost the signal, I suspected there must be something else, that causes this issue.

Since I only want to use it as a temporary solution in my home office, to drive some old VGA only 19″ flat monitors, I won’t bother with getting a new, more expensive, and probably just as unreliable adapter, I decided to try and fix this one.

HDMI to VGA converters are digital to analog converters, that notoriously tend to generate heat. There was no noticeable overheating on the cover, so I quickly took the adapter apart. The temperature didn’t change when it was plugged in,  but as  soon as I sent signal over it, it started to heat up, and the monitor started flickering. When I blew air over the exposed circuitry, and the flickering stopped. I waited again to loose signal, and blew over the adapter, the image came back instantly.

It was obvious, I only had to do something about the heat. The easiest way to deal with electronics overheating is to add a passive heatsink. I had a huge bag of electronic junk I was about to recycle, so I quickly grabbed an old (completely bricked) Fonera router, and ripped off it’s heatsink from the board. Fortunately the remainder of the original thermal paste was enough to attach it to the circuit board.

NB. The Fonera routers had undersized heatsinks, and overheated a lot, so I had to add a much bigger one for it to properly work.

wpid-wp-1446231308361.jpegSince I don’t really care about damaging such an otherwise useless thing, I had no problem cutting the cover with my Dremel, to  make space for the heatsink.

I’ve done some tests with it, to see how it works, and found, that after a few minutes of running, the sink reached about 40 degrees, and became warm to the touch, but the image seemed steady. I’d say this heatsink is barely enough to keep the temperature steady.

I seriously have no idea why they thought it should be delivered without any way of heat dissipation to start with?

2 Replies to “Hacking an overheating HDMI to VGA converter”

  1. Mozilla Firefox 41.0 Linux

    I have exactly the same issue, trying to use two old TFT monitors for a 3 display setup.

    I fixed it just dismounting the cover of the converter and putting it apart. But maybe its time to recycle for me too, and use some old VGA cooler to do what you did.

    Good solution.

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