P4ITX

Problem one: Heat

I used the copper block from the previous CPU and machined a new one to sit on top of it and bridge the gap to the left side heat sink.

I had been using Motherboard Monitor to check the temperatures but found that it was under reading the CPU by several degrees. After a trawl of the web I found another program called Hardware monitor which, although it also under read the CPU, allowed the user to adjust the temperature display. By monitoring the CPU externally while reading the bios temperature I was able to calibrate the monitor reasonably well. Initially the temperature seemed under control , the CPU at idle reaching 50 °C in my over hot workshop, however running the Nebula application highlighted the first problem.

According to the Intel web site, the 2 GHz Celeron can dissipate 53w at full load. The heat-sinks on the side of my case are rated about 0.3 K/W, so I expected it to be able to handle the power fairly well. The problem I have is that the heat meets the heat-sink in a small area some way from its middle. This means the heat sink get hotter at one end than the other; I need to spread the heat along the sink or get hold of a lower power process such as the P4 mobiles used in laptop Pcs.

After playing around with various heat pipes and shunts, the solution to the heat problem proved to be a change to a 1.8/1.2 Ghz Pentium 4-M processor (SL65Q). The CPU runs at its lower speed when installed in the Insight board but, still has plenty of processing power for Nebula and other applications.

Problem two: TV output

The two VIA boards I had previously, used a CL266 video chip and although this allowed limited adjust of the TV output settings, I was able to get it to correctly fill a TV frame. This P4-ITX board uses a SavagePro DDR chipset, and although it provides the same TV advanced control panel as the Nehemiah and Eden boards, it will only output a picture that is either too small or far too large (as well as offset to the upper right).

A partial solution, for video playback at least, is the amazingly versatile Zoom Player Pro from Inmatrix. The Zoom player has a multitude of aspect ratio adjustments which allowed me to adjust the video overlay position to fit the TV screen accurately. The Pro version has ‘TV friendly’ file navigators that make control via the Nebula remote easy.

Problem three: November and the capacitors fail

The thing started over heating (it's been stable since adding a P4-M to the Insight P4-ITX in September). I've found four of the GSC 3300u@6.3v CPU-PSU capacitors have blown (fortunately they haven't leaked all over the board) similar to those posted on ITX forums in the past few months.

The PVR does run quite warm, an ambient of approaching 40'C, but not hot enough to cause this sort of failure in a good 105'C rated capacitor ( the main PSU cap's run, if anything, hotter than the CPU cap's and they seem OK) .

I replaced the 3300uF cap’s with the only ones that I could find that would physically fit even though these were only 2200uF. They seem to work OK.