Studio XPS 435MT, replacing PSU?

It would be a waste of money to replace the psu on this 10 year old Win 7 computer. No guarantee that the power supply is bad. It might be something else. Put the money towards a new computer.

One thought- have you ever replaced the cmos battery? That would be a cheap fix. Check your manual for the right model coin cell battery. 

https://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_studio_xps_desktop/studio-xps-435_service%20manual_en-us.pdf

OK thank you for your response Mary. I will try replacing the CMOS battery...

EDIT: I tried replacing it and it did not work :S

If the replacement PSU is as cheap as the ones referenced on NewEgg ($60) I'd be very happy to get this system running again... any guidance on picking a correct replacement PSU would be so greatly appreciated.

If I was looking for a replacement power supply I would find the model number of the existing power supply. You can try entering your Service Tag at www.dell.com/support and looking at the System configuration / Original configuration or open the case and look at the power supply for a model number. You can then use eBay and search 'power supply for Dell Studio XPS 435MT'; you will find power supplies from around $30 to $40.

While on the Dell support site you can also download the service manual which shows you how to replace the power supply.

I doubt if the problem is the power supply.  The MT series generate a lot of heat and likely some of your capacitors probably went bad.  If you have access to a voltmeter check the voltage on one of the older sata connectors (most probes fit easily into the older satas).  There should be 5 and 12 volts.  If bad, just about any 500watt or better will work.  I posted a picture here of what a  bad cap looks like on my junked XPS-435MT motherboard.  I have replaced dozens of caps over the years but it is not worth the effort on this board.  Check your messages, I will try to send you a pm.

[EDIT] FWIW, that capacitor is rated at 105c temperature which indicates how hot it gets down there.  Too bad the MTS cannot use low power Xeons.  I tried getting one to work but it didn't.

I am having a similar issue with my 435MT not waking from sleep properly.  This was a well discussed issue back in 2011/12, e.g. https://www.dell.com/community/Desktops-General-Read-Only/Studio-XPS-435MT-wont-power-on/m-p/3803686.

Like you, I changed the CMOS battery, but to no effect.  I am looking to replace my PSU with a new Corsair CX450 based on advice in various community forums, but am not sure about the fan position (as per another post).

As for Mary G's comment about this being a waste of time, I had similar thoughts, but believe in trying repair vs replace and it could be £60 (I am in the UK) well spent.

Let me know how you get on.

G

Do you hear a series of beeps comping from the computer when the start button is pressed? The beeps will come in segmented dashes and dots. It's a diagnostic 'beep' code that address the area where the problem is. Count the number of dots and dashes. It should repeat itself.

A long quiet space and a new series of beeps means there's more areas that need attention. 

CX450 is TOO SMALL and does not have enough combined power on the 3.3v /5v rails.

Anyone have success with replacing the PSU on the 435MT? Any recommendations on which PSU works?

No those will not work.

Bare Minimum recommended replacement is evga 700BR

You must have 150W combined on the 3.3v/5v rails or its not working.

700 B2 BQ G2 W1 N1 from the same vendor do not work.

https://www.bestbuy.com/site/evga-700w-atx12v-eps12v-80-plus-bronze-power-supply-dc-dc-technology-black/6346160.p?skuId=6346160