Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

[litec systems]

Hi everyone,
I have dell 7010 DT ( SFF) with bad PSU

THERE'S NO 5V standby\ litting LED near the power input ( I'm assuming it's the same circuit? &#128578

I'm neither too professional \ have zero clue in SMPS, I'm somewhere in between, that's where and why I'm need your help please 🙏 🙂

By a kinda quick search here's the conclusions for now ;
the main fuse IS OK ( there's continuity, so I'm guessing that it's not too hard to repair ? 🤔 🙂

THERE'S NO visible bulged capacitors

THERE'S NO 5V standby \ litting LED near the power input


For now, from a quick random culprit search, the only thing ive found is R604 ( fusible resistor between the primary & secondary PS sides? &#129300 it looks like it was kinda explode..

The question is, how to test with DMM nearby components, and which ones from the surroundings you think might be bad toi because of that?

And how to tell its value & get a replacement?

** not sure if it might be related \ help for diagnosing, but the PSU was kinda dusty, not too bad, but had some more dusty points, is there a chance that all the other components are fine and that the R604 gone just because of spot overheating?

Which more tests& components i have and able to test with a DMM?

Any help would be highly appreciated 🙏 thanks!
I've attached some pictures of the PSU and the R604, let me know what else to take photo of, if needed

[stj]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

the TNY279 has exploded and taken r604 with it

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

Oh, now that you said that, I've looked closely and it's
have cracks😢
What can cause this? Or its just aging \ MTBF?

Can i scrap replacements from another random ATX PSU?

[stj]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

TNY do have a reputation for just dying,
but you need to check the output diode isnt shorted.

if you can salvage parts - why not.

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

but you need to check the output diode isnt shorted.

if you can salvage parts - why not.

That diode is one of the heatsink attached components or those that on the other side? ( kinda giant (&#128513SMD diodes?

And just for future understanding and learning what's that TNY279 IC does? Is that the mosfet driver?

Sadly I did a quick random search on my scrap boxes and didn't find anything even with the same layout 😢 do you have suggestions on which electronics appliances i can find such IC? ( by competitive brands like hp& lenovo\\\ different appliances like TVS? ( i know that the " best " solution is to get an used working one, but I'm want to try to fixed it for improving my skills, and I know you can't trust ebay \ aliexpress for original IC REPLACEMENTS so that buying it by model won't help me because there's a good chance that it'll might be fake\ used with almost maxed out MTBF


Thanks for all sir! 🙏

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

if you can salvage parts - why not.

BTW, if you please can help me to find an replacement IC on eBay that will fit, it'll be great too 🙏( i saw very cheap psu on eBay, but the shipping to my location cost x5 times than the PS 😐😢

[stj]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

https://www.digikey.com/en/products/...Y279PN/1007188

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

https://www.digikey.com/en/products/...Y279PN/1007188

The shipping costs sadly still pretty high, BUT! 🙂
I've just found an OLDER dell PSU ( from the core 2 dou series, probably of optiplex, 755\ 780)
an TNY267, that PSU has some blown caps BUT IT IS TURNS ON 🙂
Do you know \ can check for me please if it's compatible or not?
Many thanks sir🙏

[stj]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

i have no idea.
but there are a couple of those with a design error - post a picture of the inside

[Gatolina]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

The shipping costs sadly still pretty high, BUT! 🙂
I've just found an OLDER dell PSU ( from the core 2 dou series, probably of optiplex, 755\ 780)
an TNY267, that PSU has some blown caps BUT IT IS TURNS ON 🙂
Do you know \ can check for me please if it's compatible or not?
Many thanks sir🙏

Unfortunately Tny26x and Tny27x are not compatible. They have different pinouts

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

i have no idea.
but there are a couple of those with a design error - post a picture of the inside

If I'm understanding the circuit right, the TNY IC is on the same area of the psu

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

Unfortunately Tny26x and Tny27x are not compatible. They have different pinouts

ok thanks do you know where i can scrap similar pinout IC[different IC manufacturer but same pinout] maybe hp\lenovo?

[Gatolina]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

ok thanks do you know where i can scrap similar pinout IC[different IC manufacturer but same pinout] maybe hp\lenovo?

I don't think there is anything compatible. Have you tried Aliexpress?

[litec systems]

Re: Need help with Dell 7010 dt PSU repair please ( liteon L250AD-00

I don't think there is anything compatible. Have you tried Aliexpress?

Actually didn't tried, I'm afraid of fakes etc 😐