Z800 Power Supply replaced with Z840 Power Supply

[yyzSB]

I have 2 failed Z800 power supplies (1150 watt version). After some internet research I am led to believe this is a common problem and related to the PS capacitors. Since I do not know how to do this capacitor replacement (yet). I thought I would buy a new PS. However, I do not want to buy a Z800 PS since it seems to me to be a defective design. Can anyone chime in and tell me if the new z840 1125 watt PS will work with my older z800?

I have called HP support and spoken with the correct support people on this and they were not able to confirm if the Z840 PS will work (fit) on the z800. The closest confirmantion I recieved was that if it fits then it should work.

Instructions to fix the capacitors:

http://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Z800-power-on-issue...

Same issue I am facing:

https://www.youtube.com/watch?v=f563JGeoxaw

On a side note, can anyone recommend a good service tech to make such capacitor repares in Southern California or insrtuctions on how to make this repair (with pictures).

Thanks

[MtothaJ]

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@yyzSB wrote:

I have 2 failed Z800 power supplies (1150 watt version). After some internet research I am led to believe this is a common problem and related to the PS capacitors. Since I do not know how to do this capacitor replacement (yet). I thought I would buy a new PS. However, I do not want to buy a Z800 PS since it seems to me to be a defective design. Can anyone chime in and tell me if the new z840 1125 watt PS will work with my older z800?

I have called HP support and spoken with the correct support people on this and they were not able to confirm if the Z840 PS will work (fit) on the z800. The closest confirmantion I recieved was that if it fits then it should work.

Instructions to fix the capacitors:

http://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Z800-power-on-issue...

Same issue I am facing:

https://www.youtube.com/watch?v=f563JGeoxaw

On a side note, can anyone recommend a good service tech to make such capacitor repares in Southern California or insrtuctions on how to make this repair (with pictures).

Thanks

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Almost certaintly its the PSU, check the below thread:

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Z800-power-on-issu...

[--ies--]

Exact same problem..
Also have 2 failed Z800 1100-1250W supplies. Looking for tech support for electrolytic capacitors replacement in Silicon Valley and/or SF bay area ()

[jaymemaurice]

I have repaired a couple HP/Delta z800 supplies sucessfully.

The last one I soldered in some new Rubycon USG 450v 270uf (Digikey 1189-3845-ND) to replace the Nippon Chemicon caps. It cost ~$21CAD for the parts.

The Nippon Chemicon were rated at 105*C vs the 85*C versions they replaced - but who really cares about the ratings when they failed early. 

You will need a good iron or at least one capable of getting the heat into the solder as the board is basically a gaint heatsink and the solder has a high melting point. I used quickchip solder to help sgnificantly lower the solder's melting point and make my life easier. 

Perhaps my house might now burn down or the $$$$'s of hardware inside the z800 will fail - but that's the risk I decided to take and your mileage may vary. 

[jaymemaurice]

Spoke too soon. The supply is still unreliable. I purchased a z820 power supply with the intent to mod it into place. 

The power supply physically fits but it's wiring is not compatible. There is no 5v standby power, but instead 11v...
There are actually 12v wires going to former ground wires and visa versa. I assume it instantly shorts when plugged into the z800 chassis. 

[hcken]

@jaymemaurice: did you ever get this going with a Z820 PSU in a Z800?

I'm having PSU issues with a Z800, and as everyone else has noticed, these PSUs have a tendency to fail. I've opened it up to examine the capacitors visually, but found no evidence of failed capacitors (no buldging, no leaks, no residues). I know capacitors can fail even with no visual signs, so I might have to diagnose this further beyond just visual inspection. My PSU ocassionally does work, but after prolong use, it goes back into clicking on and off or won't power on at all. So, I suspect whatever is wrong with it internally is very borderline, and hence no visual signs yet.

BTW, how did you decide to replace the capacitors you replaced? Did you find visual signs? Did you do a deeper diagnostic procedure? Use an ESR meter?