Well after the success last weekend in getting the SP-D07 up and running properly I tackled the decoder this weekend (see towards the end of this post).

There are a couple of components in the area indicated in the other post that are labelled on the PCB as IC's (look like transistors) that get quite hot when the unit is running. One is in fact attached to it's own heatsink. The solder joints on the components didn't entirely present as dry joints, but one appeared to have had solder applied very sparingly and both appeared to have had some visible effect on the protective coating applied to the PCB near them. I'm guessing this was due to the heat they generate. They both just looked a bit suspect.

So I re-soldered all those joints, applying the solder a little more generously this time. There were also two pins from the heatsink soldered to the PCB, presumably with some kind of grounding function. They did show some dry joint characteristics so I re-soldered them too. With a good check over the rest of that area and then the whole board all the rest of the soldering looked fine.

It didn't seem like I'd actually done very much, but at this point I slipped the PCB back into place and took it for a test run. With a signal from the player the unit indicated it was receiving a muse signal and straight up the DVDO light turned green (signal present) then blue (compatible signal being processed) - Success

The audio interference/hum was also now reduced to the point that the amp had to be at an unrealistically high volume to really hear it. At a normal listening levels you basically had to stick your head next to the speaker to hear it

After feeling down on luck with two components playing up I now felt the opposite - lucky they had both been so relatively straight forward to fix. Plus there's the sense of achievement in having done it myself.

In doing a bit of reading before last weekend on identifying dry joints, it seems these are a more common reason for device breakdown than most people might think. I was reading a few stories of peoples score from the bin that only needed some time with a soldering iron. I was hesitant at first myself, but if you can use a soldering iron at all, and something is playing up (most particularly where an intermittent fault is the issue) all I can say is give it a go!!

Voltage regulators, I'm betting.
I'll be taking a soldering iron to a Sony home-theatre receiver pretty soon, on a hunt for similar problems. Meanwhile I am going to have to fabricate or obtain an entire upper clamp assembly for a Hi-Vision LD player...