Battery Backup, XPS Studio 435T

For what its worth. I picked up an APC SUA 1000, a refurb with new battery for $169.

It works with the new Studio XPS 9000 line and passes the self test with flying colours

Make certain that you get the newer model with a usb port !

We just bought a Cyberpower PP800 at work and the boss let me bring it home to test on my 435T.  Took it out of the box and plugged my 435T, 24" LCD, speakers, external hard drive, and cable modem/router into it. Pulled the plug and everything kept right on running without a hitch. SUCCESS AT LAST!  The Cyberpower PP800 is a true-sinewave model (550W) and is $239 at Dell, so it must be available at a better price elsewhere.

Goldfish1,

I agree I with you that the XPS 435T power supply is less than ideal given that that this is a consumer grade PC that will not work with a consumer grade UPS. What really bothers me though is that I checked this in advance.  I had two key requirements 'external' to the computer:  

1. that it was suitable for use with three nVidia graphics cards and,

2. that I could use my APC Back- UPS XS 1500 with it.

It was a nightmare to get the nVdia cards to work, but they do now thanks to Microsoft suggesting I try an older BIOS. Dell said nVidia cards were not spec'd for this computer so when simply reloading the driver did not work, Dell tech support said they could not help further with non-standard equipment.    nVidia - non-standard?? The two emails I sent to Dell sales asking them to confirm that nVidia cards would work before I bought the computer were ignored.

Regarding the UPS requirement,  I added a UPS as an accessory when 'building' the computer on the Dell website, just to see what was compatable and the APC Back-UPS RS (or BR) 1500 came up. This is basically identical to my Back-UPS XS 1500 , so I was confident my UPS would work. Well, it did not work when the AC power crashed last week (or during subsequent self-tests), and all Dell Tech support would say is I need to buy a higher end UPS. (The first tech support guy said he'd call back in one hour, and never did).  So what I find frustrating is I did everything I reasonably could beforehand to confirm my UPS would work, and when it doesn't, Dell basically says tough luck, buy a new one.

On a whim, I telephoned Dell Sales yesterday and asked if they had a UPS suitable for my computer (the Service Tag clearly identifies this as an XPS 435T). The gal in Sales recommended the APC Back-UPS RS 1500, Dell P/N  

A0973336 complete with 'Stepped approximation to a sinewave'

Having discovered this issue in these forums after my AC power failure last week, I asked if she would confirm with Tech Support that this was the right UPS... after 10 minutes she said yes, this will work, and she emailed me the quote.  APC confirms the quoted UPS will not work.

It was mentioned by someone else that at least a note advising of the change in power supply design would have provided a heads-up to UPS owners, but it seems Dell was not aware of the issue. 

Basically, Dell mis-spec'd (then and now) the accessories, and it seems never tested them together. Then when they don't work, its my expense to fix the problem.  So agreed, this power supply is less than ideal.

In July we got a Dell 435T computer, and had bought the APC RS1500 about a year ago for our previous computer, XPS 710. Ran fine on the 710, but the UPC will not work with the 435T.  We also have a family member that just bought a xps 9000 (same as 435T) and an APC XS 1300. That APC does not work on her computer. Very frustrating. Called Dell tech support on both, really no help! Said they do not support third party hardware and we would have to take this issue up with APC...... So far, have not been able to come up with a solution.

You have to use a "true-sine wave" type UPS. The power factor correcting power supply on the 435T/9000 will not accept the stepped-waveform of the low-end UPS's. I bought my Cyberpower PPS800 for about $200 new including shipping. Works great with my 435T.

I'm doing great with an APC SmartUPS 1000.

If you dredge-up the old "435/8000/9000 is-it-shipping" thread (something like that; it was HUGE!), you'll see a posting from Chris with Dell, listing a few sine-wave UPSes known to work.  Some people also *were* able to use stepped-sine with the 435/9000, but it is "hit or miss".  Sure-fire solutions include:

• Get a true sine-wave UPS (at LEAST 750VA).
• Replace the cheesy 435/9000 power-supply.

One solution I didn't try was putting a line-conditioner (heavy transformer) on the output of a stepped-sine UPS.  That will clean-up the wave-form some, but a) will run the transformer a bit hot and b) I'm not clear if the problem is waveform or switch-over time.  There is a delay between power interruption and when the UPS inverter kicks-in.  If the delay is too great (it is greater on the cheaper units), the computer will shutdown.

You have to use a "true-sine wave" type UPS. The power factor correcting power supply on the 435T/9000 will not accept the stepped-waveform of the low-end UPS's. I bought my Cyberpower PPS800 for about $200 new including shipping. Works great with my 435T.

We also have a Dell 435T. Our previous APC RS1500 LCD did not work on it, so we just purchased the CyberPower PP800SW (sine wave) , have had numerous problems with the software not showing a battery backup is connected, happens at least once a day, unit not going into battery mode, and buck light staying on, (Cyberpower says our power must be spiking),  or could be the unit is defective, etc.  we are now returning the unit. We are now ordering the APC Smart-UPS 1000VA (sine wave). Very frustrating! Hopefully this will be the last one we have to buy!

At our office we also had quite a few problem with the servers not communicating properly with the non sine wave UPSs. We upgraded our servers and instead of buying UPSs we moved over some of the Back UPS 1000's we had to protect the server. All sorts of strange things started happening and after some troubleshooting we narrowed it down to the UPS. Many active PFC power supplies don't get along with the square wave or simulated wave UPSs. We bought three SUA1500RM2U's, the 1500 rackmount 2u which are all sine wave. Installed them in the racks and haven't had a problem since.  We got the hint when last year we had to replace our Cyberpower's because the cheap ones weren't compatible with Mac power supplies, again, we replaced those with the Smart-UPS 1500's and have never had a problem since. The sine wave UPSs are just better. They're more industrial and definitely more reliable.

Okay - so my three and a half cents on this issue.  Hopefully it will help.  I too have an XPS Studio 9000, and I too had the issue of the battery backup unit not being able to power the unit.  I had an old Geeksquad 685U battery backup which did successfully power my computer when the power went out (but one too many nearby lightening strikes this summer prompted me to look for a new unit).  I purchaed an APC Backup UPS 1300 before knowing about the pure sine wave requirement.  Obviously it didn't work.

I went back and found the owners manual to the Geeksquad backup ups I had to find out why that one worked and the APC didn't.  Come to find out the Geeksquad unit used a simulated sine wave form for power when on battery.  I went out and purchased a CyberPower CP850AVR LCD backup UPS (got it at Staples on sale for $100 - http://www.staples.com/CyberPower-Intelligent-LCD-850VA-9-Outlet-UPS/product_749893) and it did the trick!

I know the unit I purchased isn't a gorilla like many of the UPS units people tend to slap their computers to, but maybe it's my preference that when there are severe thunderstorms in the area, or in cases of a power failure - the only thing I'm interested in doing is shutting my computer down so there for I don't need a unit to power my computer for the next hour.

Hope this helps people in the same situation!

Rich

I just discovered the incompatibility between my Studio XPS 435T and the APC XS 900.

1.  Why does replacing the power supply resolve the issue?

2.  How do I choose a replacement power supply (read: how do I know which ones allow me to avoid this issue)?

3.  Are there any pure sine UPS devices available now under $200 that will allow me to avoid this issue?

 Thanks in advance!

One more question... are pure sine, true sine, & adaptive sine all the same thing?

At least one of the power supplies Dell uses for this system is sensitive to the simulated sine wave found on low end UPS systems. The Cyberpower PP800SW has worked great for me since I installed it over a year ago. $190 at Newegg.

Irv, I ran in the same type of problems. Had to return an APC BackUps toBest Buy. I now have an APC SUA type that works fine. The 435T did not miss a beat when I unpluggged the AC cord on the UPS. I did not want to spend that much money either. Went to the APC website and their factory outlet store. I could have saved about $100 on a newly returned unit. But I decided to follow the link on that same web page to the APC Certified Pre-owned UPS partner. They sell refurbished (older units but completely checked out and guaranteed for 3 years). I saved $270 on an SUA1000. Hope this helps. Paul