Electronics repair part 2

The school had a broken projector, The diagnostic code indicated that it had a faulty temperature sensor. With some research I found out that the problem can be caused by a faulty fan near the projecting lens.  If this was the case – cleaning the fans might fix the projector. I would just need to take it apart to get to the fans.

Add OK, where are the screws I need to remove

This was my second attempt at electronics repair. My first was to see if the keyboard problem with my old computer was in the ribbon cable. It wasn’t or what I did did not fix it, so my computer is still broken. That exercise did give me practice with taking something apart, carefully, dealing with ribbon cables and connections, and putting things back together.

I was hoping this attempt would be more successful. So, with a screwdriver and a clean table – I got started.

OK, so that's the first part

There were nine screws holding the case in place. Some of the screws were not easy to find, so patience and careful examination rather than advanced technical training and equipment.   Luckily, as is common in manufacturing, the screws were the same size. Otherwise, I would need to keep track of where the screws went.

The light, which I took out to see if it was hiding screws (it wasn't).  And the screws I hope to properly put back.
The circuit board was connected to the top of the case by two cables, but I only needed to disconnect a power cable to get access to the circuit board.

The circuit board had 4 screws, one different from the others, so pretty easy to arrange so I could reassemble. However, there were at least 9 cables that I could see connecting the circuit board to the rest of the hardware. I wasn’t all that keen on marking and disconnecting so many cables.

OK, a lot of cables.  The fans are in the lower left.
This is the plastic frame for the air filter.  Hmmm.

I did notice the plastic frame for the air filter was missing the air filter, likely a thin bit of foam. So, I felt it was possible that the fans might have gotten dirty.

I tried to move the circuit board aside to get access to the fans. I couldn’t get to the fans easily and didn’t want to get more involved so I got out my can of air and blasted the two fans.

A can of compressed air - the repairman's friend!
Unfortunately, there was some safety switch I could not find that did not allow power to the machine until I put everything back together to see if blowing out the fans had temporarily fixed the problem.

When I had it sort of, but not completely, back together I plugged it in to see if I fixed it. Nothing. No power. Nothing. However, also not spark and no small of burnt electronics.  So, I knew that I didn’t do anything to completely break it, but I can’t help but think for a second that I had.

Still, I figured there was some switch somewhere so I continued on with the screws. When everything was back together and no screws remaining on the table I tried the projector.

And good news is that the projector is now working.

OK, it works.
This fix will only be a temporary one. However, knowing what I know now, if all I wanted to do was just to blow air into the fans, I could have done that without removing the cover (although it might not have been as effective).

A better solution would be to get a replacement air filter and to truly clean out the fans. That will have to wait.

My original preference was to find an electronics repair place on the island. However, I was told that was not an option. As a Peace Corps volunteer in Ghana we were taught to try to figure things out with available resources. And, I didn’t really want to leave a broken projector taking up space – the planet has too much electronic waste already. So I am glad that this little project worked and that I had something sort of interesting to write about this week.

Love always,
John


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