Dell Precision 470 Workstation

[jrm000kc]

Re: Dell Precision 470 Workstation

Sorry to bug you again Toasty, but I need to ask about the fuseholder. I'd like to install a fuseholder that would allow me to replace the fuse quickly without having to solder. Any ideas?

[jrm000kc]

Re: Dell Precision 470 Workstation

I'm having a hard time finding an exact match. The closest one seems to be a Honeywell (Mouser#785-ICL155R007-01). The temp variance is -40C to 185C. Mine is -40 to 200C. Is this a close enough match? I'd hate to order it and find out it's the wrong one.
Looks like I'm SOL finding a used power supply. The only option is shelling out $200 for a new one so I'm pretty much stuck with the repair option. I'm hoping it was an overheat problem since the PSU fans were completely plugged-and the act of shutting it off made the fans stop and pushed the temp over the edge. At least it didn't happen while the PC was on...
That technical jargon on the graph you graciously sent makes my mind feel like it's stuck in mud-especially when I'm trying to cross reference a match. I guess you learn something everyday-it's just a matter of realizing it.

[Toasty]

Re: Dell Precision 470 Workstation

608 is a manufacturer's date code.

No, Radio Shack won't have the part(s). See the list I gave above.

T

[jrm000kc]

Re: Dell Precision 470 Workstation

Would Radioshack have that thermistor? I need a soldering iron anyway-I'll pick up the Weller that they sell. I'm sure I can get the fuse from there-but finding a knowledgeable staff person probably won't happen.

[jrm000kc]

Re: Dell Precision 470 Workstation

Thanks Toasty!

I get the SCK057-so what value does the 608 represent?

[Toasty]

Re: Dell Precision 470 Workstation

SCR? Do you mean SCK?

Also, its 3 separate lines.

SCK
057
608

See attached.

T

[jrm000kc]

Re: Dell Precision 470 Workstation

I got the fuse out, so no problem figuring that out. My NTC thermistor is exactly the same as the cracked one shown on page 5 of this thread. No manufacturer, just SCR057608. Once I figure out what I need, I'm going to get a soldering gun and replace it along with the fuse I pulled and see what I get.

[Toasty]

Re: Dell Precision 470 Workstation

Need pics of the parts and numbers from them.

T

[jrm000kc]

Re: Dell Precision 470 Workstation

So what type/value NTC thermistor do I need? I'm also not sure what type/value the fuse is coming from the plug in.

[Toasty]

Re: Dell Precision 470 Workstation

Those aren't Dell supplies. They're an off-brand. Fitting it in that clamshell case is up to you.

Repairing it is still the best option.

Parts are available from DigiKey, Mouser, Avnet, & Arrow.

T

[jrm000kc]

Re: Dell Precision 470 Workstation

If it helps, my PSU reads D550P-00 model number. P/N is DPS-550DB A Dell P/N is D1257 A tech at a surplus store said spending the money on a PSU is worth it. He said the dual Xeon processors are an awesome setup, especially if I could get Windows 7 to work. Anyhow I'm trying to figure out where I could get a replacement thermistor and what kind of fuse I need. I was looking at PSU's on cellularfactory.com, particularly thisell Precision 470 A-Power AK 750W 20+4-pin ATX PSU w/SATA & PCIe (Black) Dell Precision 470 A-Power AK 750W 20+4-pin ATX PSU w/SATA & PCIe (Black) My question is how is it supposed to fit?

[Toasty]

Re: Dell Precision 470 Workstation

Yeah, sounds like the same problem the Apple G5 Mirror Door Samsung supplies had with the open mains cap. <BANG!>

T

[kc8adu]

Re: Dell Precision 470 Workstation

yes thats a heavy one iirc.last one i had here had open lytics(450v)in the pfc.the mosfet was shorted and ntc splattered.if it has the samwha 450v caps replace them.

[Toasty]

Re: Dell Precision 470 Workstation

No schematics - proprietary information.
Bridge = bridge rectifier = converts AC to DC
Choppers = switchers = MOSFETs that switch or "chop" the power to the circuit to make an SMPS work.

Prices online vary from $150 to $200 +. Confirm this is a DPS-550DB A.

If you want to consider a repair, we can talk. The killer is the shipping. Probably $15-$20 each way.

T

[jrm000kc]

Re: Dell Precision 470 Workstation

I've given up trying to repair it. What's a good online site that sells these?

[jrm000kc]

Re: Dell Precision 470 Workstation

This is my first time attempting to repair a circuitboard. Bridge and choppers are Greek to me. Finding a schematic is like finding hen's teeth-even on the internet.
A guy told me yesterday that snipping out the bad thermistor and replacing the fuse should make it work-unless there's other problems. I'd just replace it but they cost at least $150-and countless companies are throwing them out right now. I guess I'll find a computer surplus/recycling company. These 470's are getting replaced right now so it shouldn't be that hard to find an old one. (I hope.)

[kc8adu]

Re: Dell Precision 470 Workstation

ntc sometimes fail.most are killed by something else.check the bridge,choppers,ect.

[jrm000kc]

Re: Dell Precision 470 Workstation

I have a 470 I purchased from where I used to work. I replaced the useless video card with an NVidia GT 450 and the performance has been exceptional on the newest games out there. She's been a nice PC.
However, last week I shut it down and my wife heard a buzz of electronic death and a burning smell. I took out the power supply (which no retailer has) and I also have a blown NTC1 thermistor. After reading this thread it serves as an inrush limiter correct? It's the only thing I see fried on the circuitboard. I suspect the cheap carpet in my pad is the culprit. The twin fans were completely filled with carpet fiber dust so I'm thinking a static charge might have killed it. I blew out vast amounts of dust with canned air. My question is since a new power supply costs $150 can I solder in a new thermistor? Or is a blown ntc thermistor a sign of bigger problems? If anyone could show me where I can buy a replacement thermistor and what type and value it is I'd greatly appreciate it. Right now I'm using my other PC, a Dell Dimension 4600 I bought nearly ten years ago and have maxed out memory wise and with a Radeon HD 3650-this thing is glacially slow compared to my 470-I want my 470 back!!!

[69ragtop]

Re: Dell Precision 470 Workstation

Thanks for the reply michaelahess.

Does anyone have directions on testing the power supply? (what voltages on what pins, etc)?

[michaelahess]

Re: Dell Precision 470 Workstation

Did you ever resolve the issue? I have a similar machine. With one PS, I get green/amber/amber/off which indicates VRM0. It is a single processor. When trying another PS I see off/amber/off/off (i.e. solid B light). However, both power supplies will power a different 470 with no issues.

I tried and failed, didn't try again, figured I was only out 7 bucks or so, didn't want to make it more!