The PSU of my 5yr old Lenovo Q series desktop got

Check display without cabinet maybe motherboard getting short with cabinet and try new Power supply check all the power supply connectors connected or not .

If your country uses 240V mains then flicking the switch to 115V bypassed a voltage divider and probably blew the fuse in the power supply. If you are comfortable working with mains voltage, you can pop the PSU open and check the fuse. If it's blown then just get another one with the EXACT same ratings and you should be up and running again.

If it's not the fuse then you have bigger problems and it's time to replace the PSU. Any PSU should work as long as the wattage is the same as the original or higher.

Also, you could call Lenovo to see if the PC is under warranty. If so, the PSU is probably a user replaceable part, meaning they will send you a new one to put in and you just send the old one back.

I cannot argue with what you want. Since you did not tell the whole story, there is no way to answer your question.

1) Series:
It's a ThinkCentre M Series Desktop

2) Subseries:
ThinkCentre M55e

3) Machine Type:
9637

4) Model:

The Model Number will be right after ThinkCentre M55e-9637
It will be two numbers and a letter, or two letters and a number, or three letters.

Three characters. (symbol)

Some examples; 21B, 21H, 22U, 28s, 28y, B2F, B26, I2F, (i2F), I64, (i64), W2Y, W2Z, WJW, WJM

ThinkCentre M55e-9637-WJW

(Above is fictional. Just an example)

Regards,
joecoolvette

It is very possible that it is the motherboard; they tend to be unstable, especially old voltage regulators that regulate the power to the CPU. With the number of things you have eliminated, I would agree that is the MoBo, and the solution would be to replace the MoBo.

Bad PSU day: 13 year old PC, retired, at HP and legacy status.

the A series desktops are very very old, and no support now.
the problem is there is not just one PSU now,
they evolved the PSU ATX sec as things changed. in time.
any watts over 400 is ok, unless gaming and power sucking new, GPU card is added.
point 2: ive no idea at what is inside that case now
upgrades, add-in PCI slot cards, ext.? how may HDD.
or what. its old things change,
so Ill pretend nothing changed, ok/ and tell you what it has
and what to buy, buy more watts , as the bigger watt PSU is higher priced and more quality, built in. a $15 PSU is junk class.
Q1: is the power jack 20 or 24 pins.?
Q2 does it have IDE drives or SATA.
Q3 do you really use that floppy? and its silly PSU power cable.?
more watts never will hurt you or it.

ever go here.? newegg, nice , choices on left.

https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007657%20600013999%20600479293&IsNodeId=1&bop=And&Order=PRICE&PageSize=36


and see the left side under TYPE.
that must match your needs,

• first I buy quality,(and brand names) never china nonames.
• then large fan
• then type,
• More watts gains you quality line 1 above. most times.

in that order. what matters to you , I could never guess
the large fan is quiet, if you like less noise,. bingo.
this?
Lucky you no relic IDE Drives, inside, more pain.

https://www.newegg.com/Product/Product.aspx?Item=9SIA9384673962

It seems that the power supply unit has gone. If you power it on and nothing happens then obviously the psu has gone. The heat that you felt was the psu overheating because of no fan and hence no ventilation. The noise was of the faulty psu fan that got stuck or did not work and the psu got overheated and got burnt eventually. Please replace it with a new one as a repaired psu may work but you cant rely on it.

When that happens it is usually the motherboard.

To test parts you need a benchmark.

PSU can be tested using a multimeter.

Motherboard is tested using a tester like this one: PCI Test Card, PC Analyzer, Motherboard Test Card
Ram and CPU (CPU sometimes get damaged) are usually not damaged by this kind of problems, they can be tested mounting them on a working motherboard. For the RAM we also use a RAM tester that costs about $200.

Ensure also that the switch contacts to new motherboard are installed properly. A technician can test cabinet power switch using a multimeter, or carefully bridging with a screwdriver the switch on contacts on motherboard (do not do this unless you are sure about what you are doing)

Test the new PSU on a different socket, when a PSU blows , it may damage the main socket.

Also remember that new power supply units have two connectors. The big rectangular main one (24 pin) and a smaller 4 pins squared one.

As an home user you may not have access to testing equipment, therefore my suggestion is.

Ensure you are using the right PSU.

Ensure that the motherboard is connected to power switch.

Test the new PSU with a multimeter.

Examine the motherboard for blown or leaking components and burnt areas.

If you do not find anything, but the mainboard is still not working, then buy a motherboard-cpu bundle compatible with the PSU that you bought and assemble a new system inside the old cabinet.


Regards.

I have had several issues with this same problem, you may need a new power supply, because your old one may be failing and may need replacement.

My solution to this problem is that you may need to buy a need psu. I recommend either calling dell or buy a new psu.

You need to find out the motherboard make or a serial number. As this may have a slocket type fitted processor(on it's side) and makes you limited with fan types etc.