Posted this in the [H]ard forums but I didn't get a reply. Can anyone help? Ok, I'm quite a n00b to all this so these question probably seem really dumb to you but just humour me and help reduce my ignorance. These Qs are for my project to install a medium spec PC into the top of a VRC case and then use wood to finish off the enclosure front and top (I just prefer working with wood so I'm not going to mess with cutting much metal to make a front faceplate and a lid) 1. What current/voltage does the mobo hdd/power led connectors give and what current does the PSU +5V lead (molex connector) give? 1b. does this mean I can connect up extra, always on LEDs, to the molex to get some exta lights (and if not what resistors should I add or can I just do multiple parallell/serial LEDs to get the right individual volt/current)? [edit: the LEDs I'm using are ones taken from an ATX case so they would normally be connected to the mobo connectors (hence the question order)] 2. If you have a non-backlit LCD display can you put LEDs along the top to light it up like a backlit display or do backlits use a screen to dissapate the light so this will not work? 3. With the base and 3 sides of this case metal but a front and lid of wood will I have heat problems (spec of box below)? 4. Can I use 2x80mm case fans for back inlet of air and then just leave holes in the case front for the air to get out or do I need fans at the case front to push the air out? 5. Like the idea for this mod/custom job? Here's the specs: MSI nForce mobo with 5.1 Dolby and TV-out card Athlon 1Gig (may clock down to about 733MHz to reduce heat) Taisol CEK760092 HSF (not that good but quite quiet) Pioneer 16x DVD-rom (106S) (may be locked to slower speeds to reduce noise) old Maxtor 20Gig HDD 250W PSU (ripped the box open to get the pcb+heatsinks out as the full PSU box didn't fit on the case) Generic parallell 20x4 Char LCD Wireless mouse/keyboard for easy input and control Anyone who's interested here's the story: Wanted a nice DVD player and an mp3 player for comon room (primary PC in flat) and I thought a bit of low graphics gaming and genesis/n64 emulation would be fun. Decided on one of those Shuttle/SpaceWalker SV25 mini PCs but then realised that the nForce has better sound, better integrated graphics, and was just a better bet. It doesn't work out that much more expensive (especially if you get a $30 Duron but as I had a spare Athlon from a stock problem at a local store I decided what the heck, it was free why not use it). Since then the project has been boosted with the LCD idea for WinAmp display when using the sound out for mp3 payer but not TV out video and the VCR case I found in a skip. Not bad dimensions for this PC as it is a full size mobo with HDD and DVD. Think of it as the hight of a mobo with the width of a mobo and HDD together, well you know what size it is: the size of a panasonic VCR. The case is so small that the mobo touches the front and back of the case and the HSF's fan sucks air in from outside the case as it is soo high in the case that there wasn't the clearance so I put in a hole above it in the case top.
hwulex did this a while back pop over to: http://www.hwulex.co.uk/vB/ and ask him about "hwulan" and he'll give u pics. from what i remember - make sure ur mobo will fit cause i v. much doubt the msi will fit into a dvd/vhs box - youll have to get the abit nforce micro atx board. I think mobo leds are 5v arent they? anyhow you could literally rig up 100s to 1 psu and still have enough amps to spare i recon, just wire them in parallel. U got a maplins near you? if so - get some stripboard (pcb with copper strips on it) and some.. umm little jumper prongy things (like you connect the leds to on the mobo) and wire them up that way I v.much doubt ull have a heat issue, just make sure u have the psu fan and an intake near the heatsink and youll b fine.
Thanks for the link. >make sure ur mobo will fit That was the first thing I did. I actually have all the parts and much of the work done for this project already (just the LCD to install and the front panel to build - the hard part as I'm going for having the power light illuminating the power button and I have lousy coordination so anyhting fiddly is v. hard for me). The big problem with hwulex's design as I see it is the use of the full PSU unit. As many people who build custom cases has noted, 90% of a PSU us air and about 50% of that is not the necessary air above the PSU around the heatsinks. My current design fits neatly into the VCR box as the PSU itself is only actually 15cm by 9cm (out of the box) and the MSI board may take up the ful depth of the VCR case but gives a full 16cm of the left side of the case free for the PSU and HDD. The DVD drive floats above the edge of the mobo and above the HDD. >I think mobo leds are 5v I know that the power switch is connected to a 5V connector (according to the ASUS manual for my other mobo) but I haven't any details about what the activity LEDs run from. I think I'll just use an old PSU and see if connecting an old case LED to the +5V line blows it up or works. The worst that can happen is I'll loose an LED and old PSU. >U got a maplins near you? I use the online Farnell for most of my electrical orders as it is cheaper than driving to the nearest store (I live in rural Oxfordshire so often shipping from online sources is cheaper than the petrol to get to shops ) >psu fan and an intake near the heatsink I'm going for a positively pressured case with a silent 80mm rear intake onto the PSU and the HSF blowing air in from above the case (due to the HSF hight it is touching the lid of the case and so a little hole there and my CPU gets nice cold air from then outside. The front panel has air holes for the air to escape and so the air flow should be quite good (rear to front so the CPU and PSU get the cold air while the DVD drive works in the warmer exhaust air - makes sense if you think which need the colder air to dissapate more heat) Again, thanks for the help. I should have some nice pics sometime in the next 2 weeks (I've got work so I don't have much time to work on the project)
Look, I conduct! >The worst that can happen is I'll loose an LED and old PSU. Ok, I was wrong. The test results show I'm dangerous and should not be allowed around electronics. I did what I said I would using an old AT (?) PSU rated at 200W that has an old on/off switch. When there was no power the switch was easy to use (the old style switch has the power running through the on/off switch rather than just having a relay) and then I turned the PSU on at the mains. The first thing I should have noticed was how much more resistance there was in the switch when I tried to turn it on. The next thing I noticed was the arcing blue electricity moving over my hand and the switch and then the mains tripped (thank god). The LED never lit but I suspect it may be that the PSU was so old that it was defective and so the test means nothing to imply whether I need a resistor to get these LEDs working. Then again I now know not to mess with that old PSU again. Here's the new plan (tell me if this will probably work or not) that doesn't involve me being electricuted or using a molex 5V: What if I just parallell 3 LEDs from the pins for the power supply? The pins should give exactly what power the LEDs need to operate (as that is what they are for) and I can have a little switch on 2 of the 3 LEDs so I can turn them on/off when I want while the 3rd will be the actual power indicator. Will this work or will putting them in parallell cause too much power drain (3x normal drain) from the mobo and have to potential to break the mobo?
Here's the calculator you need to size your resistors: http://www.bit-tech.net/article/68/ The Motherboard headers supply just enough current for a single LED--do not parallel multiple LEDs off that header directly. The +5V connection that powers a drive will power a lot of LEDs, it's rated for a few amps. For you, I recommend that you use a resistor for each LED, and use +5V to power them. So to find your resistor, plug in 5V, 2V, 20 mA (as sample values that shouldn't be too far off for a green LED that's not an ultra-bright), and you'll get the appropriate size resistor. If you have multiple identical LEDs, you can use a single resistor for a parallel combination. Add the currents and do the calculator. For example, for 5 LEDs, plug in 5V, 2V, 100 mA. But watch out for the power dissipated in the resistor. For the above case, the resistor dissipates 273 mW, so using a 1/4W resistor would lead to a quick failure. Use a 1/2W or larger instead.
Thanks for the help. I just completed my first major mod for my VRC project by adding a window to my slot DVD drive
Ok, just one more piece of advice and I should have finally got enough info to get this mod up and running. If I use some 5V blue LEDs (link to details ) will I need a resistor as they are rated for the right voltage but I've read all LEDs need resistors when they're being run of the molex 5V as it provides a lot of power.
