User manual for power supply/ standard ATX or proprietary

[Silverthunder]

I would like to open up my power supply and clean it out.  However, I would first like to review the user manual so that I can learn how to discharge the stored electricity or how to stay away from the high voltage.  I opened up the computer and I see that the part number for the power supply is 667893-003.  I did a web search of that part number but no user manual returned in the results.  

Is there a way that I can download the manual from HP?

I know that the parts are sometimes known under a different model number or name, as well (for example, sold to consumers as an individual part), but I wasn't sure how to figure out the alternate part or model number?

On a different note, I noticed that one of the voltages supplied by this power supply is 5.09 V.  I think that most ATX power supplies supply 5V, as one of the voltages.  Is the power supply best replaced with a specific ATX version?  In replacing the power supply, should I instead use one that supplies 5.09V?  I read that HP has often used proprietary power supplies like this.

[TheOldMan]

First thing to consider - most likely there is not a user manual.  Very rarely will a power supply maker/manufacturer give out a manual showing the user how to open or clean a power supply.  They are considered a non-serviceable part.  In checking the support page for your PC

https://support.hp.com/us-en/document/c04345595

It indicates the power supply to be

• Form factor: Internal ATX
• Total wattage: 300W
• Nominal input voltage range: 200-240V/3A (50-60Hz)
• Dimensions: 150mm x 140mm x 86mm (5.9 x 5.5 x 3.4 inches)

not appearing to be a proprietary power supply

[Silverthunder]

I suppose the 5.09V rail is still within the 5% tolerance (5V *1.05 = 5.25V), assuming that that power supply is still outputting the 5.09V.  I just thought that those tolerances were so that in case the power supply was a little off in what it produced, it would still be reasonably close to the 3.3V, 5.0V, etc.  I just didn't think of it as an "invitation" to outright produce different voltages, but more as quality control tolerances.  But, maybe the manufacturer was trying to produce a 5V rail, but the voltage ended up being a little off so the manufacturer put an accurate label of 5.09V.  

[TheOldMan]

I looked at a label for a 667893-003 power supply.  I really do not know why they would indicate that voltage but I would not read anything into it as being abnormal.  Most other supplies indicate 5v, as you posted.