the humax you fix with cotton buds

I mentioned before about how my PVR, which is a Humax 9200T, had developed an odd and annoying fault.

To briefly recap the clock would "fail" when it went into standby, which meant that it would then not wake up in order to record programs.  This meant I had to leave the box on all the time.

Doing some digging around I eventually found a forum where lots of other people with this PVR were having the same problem.  Initially there were a few different ideas as to what was happening but eventually one of them had worked out that (in essence) contamination on the surface of the printed circuit board was causing the thing to short.

The solution was therefore to disconnect it and take it out of the machine and clean it.  Cleaning could be achieved using ethanol alcohol, which was most easily found in a reasonably pure form in surgical spirit and cotton buds (the ones you put in your ear but are told not to) were ideal for the actual cleaning.

As such, Saturday morning, after having returned from doing my washing I set about my PVR with a screwdriver and released the PCB.

It was quite a job, actually, as the cables connecting it to the main machine was difficult to get at and disconnect.  There were also a lot more screws than I was expecting.

Having liberated it I set about it with the cotton buds and surgical spirit.  This was quite tedious if I'm honest.  There was one particularly area of the board that the instructions said were key, so I focused there, but I gave the whole board a wipe over too.

A lot of gunk came off, but the instructions also indicated that it wasn't really dirt that was the problem as such.  Also I think a lot of what looked like dirt was actually felt tip pen marks.  I'm assuming these felt tip pen marks were put on when they were wiring and soldering the board up.

I gave the key area several goings over.  In the forum thread a few people had said they'd needed to do it a couple of times before it had worked and I figured better to overdo it than have to take the thing apart again.

I left it to dry a bit (alcohol evaporates at room temperature, so it wasn't really very "wet" and then re-assembled.  I left it for a while again and then switched on.  Initial success was achieved in that nothing blew up and everything worked in terms of showing TV channels and playing back recordings.

And then - the moment of truth.  I put it into standby and... It worked.  The standby clock came on and stayed on.  I switched it on and off a few times.  I left it in standby for a good while.  I set up some recordings, put it in standby and it turned on.

Indeed it has been working like there was never any problem in the first place.

So we have success!

And what's particularly pleasing is that Humax would have charged £30 for the PCB replacement.  This only cost me about £7.00 and that was mainly because all the local boots had was a big bottle of surgical spirit.