PVR >> Modifying the Thomson DHD4000IntroductionThe DHD4000 is a great DVR, but the noise and heat spoil it! The noise is caused by two things. Primarily, the fan produces the bulk of the noise. Additionally, the plastic caddy that houses the hard drive amplifies the noise of the drive. The design means that the air flow inside the box is poor also.
A "blower" fan, situated underneath the plastic caddy, sucks air in from underneath the box, and blows air towards the left of the box under the hard drive circuitry. However, it is so small and noisy that I doubt it has much of an effect.
Like others have already done, I set out to reduce the noise and improve air flow. Removing the Plastic CaddyThere are 5 or so screws that need to be removed. Once this is done, the caddy can be lifted out, but not as simply as one may think! At the front of the box, on the left and right side, is a screw holding the front panel onto the box. Undo these. The front panel is held in place with a few clips, which you can get to from the back of the panel. Now the black front panel should simply come off. There are no cables attached to it. Once this has been removed, there is a metal plate, which although may look like it is welded on, it simply pulls off. Now the caddy can be removed. Attempt #1: Not So GoodOnce I'd opened the box and removed the caddy, I had a think about how I'd like to modify the layout. After some thought, I intended to put the hard drive back in the same position, but not in the caddy. Instead, I would get some feet for it and sit it on the circuit board. Then, I would place a small 40mm fan next to the hard drive on the right-hand side of the box, so it could suck in air from the right vents in the case, blow air under the hard drive, and out through the vents in the left of the case. Someone once mentioned a website, http://www.dorothybradbury.co.uk/, who sells quiet fans. I bought the 40mm Delta fan. She also informed me that she sold a substance called Sorbothane for 99p per sheet, which is a sound-absorbing material that can be cut up. This is what I would use for my feet. I ordered these, and received them next day. If you want some Sorbothane, it's not listed on her site. You'll need to email her.
From QuietPC, I bought a Zalman noiseless resistor cable to bring the fan speed down. Incidentally, QuietPC charge �3.75 + VAT for Special Delivery, which I felt was completely unnecessary for a tiny cable! If you call them up, they'll send it in a padded envelope by standard post free of charge. Lastly, I bought a power adaptor cable off of eBay for 99p that would allow the fan to be connected off the hard drive power cable, so no chopping was needed. This is necessary because the original fan has a small connector, whereas normal fans have a larger connector, and so this was not fit onto the motherboard's socket.
First of all, I cut up the Sorbothane to make some feet for the hard drive to sit on.
The hard drive could now simply sit on the circuit board.
The difference was incredible! The DVR was virtually silent, and this was with the lid off! The noise of the hard drive was significantly reduced, and obviously there was no noisy fan. At this stage, I was very pleased. The drive never got hot, but the lid was off, and I felt a fan was really necessary if I wanted to prolong the life of the drive. In went the Delta fan, and this is where this attempt proved unsuccessful! For a 40mm fan, it was quiet, but even at 7V, it was too noisy, albeit a far "smoother" noise than the original fan. This was no fault of Dorothy Bradbury, and in fact my own fault. I decided that my approach was wrong, and I was going to have to use a larger fan and change the layout. Attempt #2: A SuccessI decided that the only alternative would be to do something like this guy did. Back I went to Dorothy Bradbury's site and ordered an 80mm Panaflo L1A fan. I thought this fan should be far quieter for a few reasons. Firstly, I know that these fans are supposed to be ultra quiet. Secondly, it has a fluid dynamic bearing. Lastly, it is stated that at 7V, the noise is <17dB(A), which is pretty quiet. It arrived next day again, and I put it into the box, sitting on some small pieces of Sorbothane, positioned on top of the vent, again connected to the noiseless resistor cable. I repositioned the drive, and played around with the Sorbothane feet so that it was sitting nicely. I powered the box up, and my face lit up. The new fan was virtually silent. Job done. On went the lid. I sealed up the vents on the right hand side of the case so that air is drawn from underneath the box, and directed towards to the right side. The case is now almost cold to the touch above the PSU, and I can actually feel the air trickling out of the vents in the left-hand side of the case. Both the noise and air flow are now significantly improved.
Upgrading the Hard DriveAs planned, I have replaced the hard drive with a 120GB model. The drive is a Samsung SV1203N, details of which can be found here. In essence, this is a 5,400rpm drive, with similar specifications to the original drive. For me, it is important to use a 5,400rpm drive and not a 7,200rpm drive, due to the small enclosure and the subsequent heat build up from a 7,200rpm drive. Quite simply, a rotational speed of 7,200rpm is not necessary for a DVR. Even a 5,400rpm drive is capable of far more than the DVR needs. The first thing I did was put the drive into a PC and run the HUTIL utility to set the acoustics of the drive. In a DVR, a drive configured for performance is simply not needed, and this is how hard drives are setup by default. The utility can set the drive to "quiet" mode, which will decrease the noise, and should also mean even less heat from the drive, whilst still being more than adequate for the DVR. Once this was complete, the drive was ready for the DVR. The jumper must be set to "cable select", but apart from that, there is no other preparation involved. It does not need to be partitioned or formatted. It can go straight in. Once I connected it up, I could see a potential problem. The new 120GB drive is a bit deeper than the original, and due to the modified layout inside the box, the drive was going to sit very close to the top once the lit was put back on.
Luckily, it fitted in, but only by a few millimetres or so! Had I not modified the layout and was still using the plastic caddy, the size of the drive would not be a problem as far as I can see. The lid went back on, the box booted up fine, in fact a lot quicker than normal. The drive is very quiet, certainly a bit quieter than the original, but this impression is only from spin up. Once I've used the drive a bit more from day-to-day, I'll see what the acoustics are like, but first impressions are very good.
Update: 11/05/2005 Update: 23/07/2005 Questions or Comments?If you have any questions, comments, or feedback about anything on this page, please feel free to get in contact with me. |
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