On Thu, 17 Apr 2008 09:09:17 +1200 Volker Kuhlmann <[EMAIL PROTECTED]> wrote:
> On Wed 16 Apr 2008 18:01:11 NZST +1200, Steve Holdoway wrote: > > > I'm trying to get an old Hp system refettled to run for some friends > > kids. However, the mobo is running a 600MHz cpu, and I've only got > > 64MB of memory for it. I've got a spare mobo with a pentium on it > > ( only one, as it's the 24cm square size ), which I want to use. > > However, it's a non standard psu, and hasn't got the 4 pin extra power > > connector on it. Is it safe to make up a converter to use the spare > > disk power supply connector? I've got plenty of old dead psus/disk > > power splitters I can rob the fittings from... > > Worth a try, but whether it's safe depends on more factors that haven't > been mentioned yet. Like whether you make a mistake with getting the > pin-outs right... ;) Errors here tend to let the smoke out. You have > verified that the 4-pin connector only carries gnd, +5V, +12V? Nothing > else is on a drive connector. > > The idea should work, although it's not totally optimal because of cable > lengths and how they run. One potential pitfall I can see is if the PSU > has more than one regulator circuit for the +5V, then connecting them > together can severely interfere with the regulation and cause the > voltage to oscillate, possibly with peaks into dangerous levels (and the > electronics won't work with that). PSUs for AMD CPUs with a total power > of (guessing) 350-400W and above have that, to keep the +5V current > below 20A per regulator. If the total +5V current is below 20A you > should be fine. If you wanted to make sure, connect an oscilloscope and > turn the power off fast if it shows an epilectic. > > (The mobo may connect the 4-pin-consector lines with the main connector > lines.) > > My feeling is you should be fine (but I take no liability). Leave the > RAM and CPU off and connect it up, turn it on, measure the voltages with > a multimeter. > > > Steve PS yes, all Volker's comments about software engineers and > > soldering irons are true in this case, but I reckon even I can manage > > this! > > *vbg* You should be fine. If you weren't, you wouldn't have asked the > question as competently. > > -- > Volker Kuhlmann is list0570 with the domain in header > http://volker.dnsalias.net/ Please do not CC list postings to me. Just a quick update on this. Yes, I did get it working, and plan a) worked, and all the lights stayed on. I was very careful not to use any extra cards to keep the power requirements as low as possible. HOWEVER... it's a really good idea to look at the shape of the board, and where the connectors are / size of cpu fan, etc. There's absolutely no way at all that the board will fit round the cd player or the psu! Lesson learned there... (: Steve -- Steve Holdoway <[EMAIL PROTECTED]>
