IBM PC 350 PC Desktop power supply unit specs??

check the board visually if you have some bulged capacitors near cpu or north bridge but in most cases also near sata controller.
if you have then replace the capacitors usually tyhey are designed for 6,3V 1000uF or same spec for 16V
all caps are 105C.
also you need to replace them in the power supply.
now days the factory giving low strenght psu to high spec computer.
get some corsair power supply between 800-1000W
i know that is to much but then you can do upgrade later on such as graphic or cpu or more ram.
finally test the voltages on mos fet transistors.
usually people asking why this happen
it happens because the main is not filtered and usually no many home user have upc backup with power filter and the seccond thing is
the fact when the board request more power from the psu then the psu drain more down and when the oscillator on the primary circuit start to catch up then the capacitors blow up by the time.
sometime the 5V goes up to 12-or 16
in this case most component suffer like sata controller or north bridge.

Possible.

Here is a AWESOME guide on converting the power supply to a general power supply (lab). It has all the wiring and voltages.
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

Bad Power On switch, or bad Power Supply.
(Weak voltage power rail)

The Power On switch is located inside the plastic Power On button.
This is an example of a generic ATX power on switch,

http://www.directron.com/atxswitch.html

One that I have found fits many desktop computers.

There is a test to see if the problem is the Power On switch, or the Power Supply.

The test requires using a jumper wire on the ATX main power cable's connector.
Jump the Soft Power On wire (PS_ON) to ANY ground wire.

This is Lenovo Support, ThinkCentre S51 desktop computer, User Manuals, and the link to download the HMM.
Hardware Maintenance Manual.

Left-click on the top blue file listed.
Starts with - Hardware Maintenance Manual (HMM) (March 2009) Thinkcenter A51........and ends with S51 (type 8098, 8171, 8172, 8173)

Date to the right is 2009-08-05

On the next page look under the heading - File link, and click on -
19r0486.pdf in blue.

This is a PDF file. It may take as much as 30 seconds before you see the first page. Additional time may be required to fully download. Let the file download all the way before looking through it.
(Took 4 seconds to see the first page, and over 3 minutes to fully download just now. Medium speed DSL connection)


With this HMM you can follow along with illustrations, and details, as I detail how to perform the above test, on your IBM ThinkCentre.

(FRU = Field Replacement Unit)

S51 is the Product Model.
There are several Types.

Page 98 details how to open the ThinkCentre S51 desktop computer. ('Pizza-box' computer case)
(Types 8095, 8141, 8142, 8145, 8420, 8421)

Page 123 details how to open the ThinkCenter desktop Tower computer case.
(Types 8143, 8144, 8146, 8422, 8423, 8427)

Page 145 details how to open another 'Pizza-box' style computer case.
(Types 8098, 8171, 8172, 8173, 8424, 8425)

Computer unplugged from power, observe Anti-Static Precautions, BEFORE you reach inside.

Anti-Static Precautions:
Your body carries Static electricity.
Static will fry out (Short Circuit) the hardware components inside a computer.
Computer unplugged from power, TOUCH the metal frame of the open computer case. Touch an unpainted surface.

This action will relieve your body of Static.
Should you leave your computer in the middle of working on it, be SURE to Touch the metal frame again upon your return.

With the flat desktop models, ('Pizza-box') you may have to release the lock, and tilt the Harddrive, and optical drive up. (CD/DVD drive)
This will allow viewing the motherboard.

With the desktop tower model you may have to ease a few cables over to view the motherboard.

You are looking for the 20, or 24-pin ATX main power cable.
(Don't know if your model uses a 20-pin, or a 24-pin.
This is what you're looking for,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

Scroll down to see the 24-pin ATX main power cable.
Look at the photo to the far right.
The Green wire is the Soft Power On wire.
ANY Black wire is a Ground wire.

With the ATX power cable plugged into the motherboard, as shown in the photo to the far right, you are going to insert a jumper wire down into the socket holes.

The jumper wire goes down in the socket hole, Right next to the wire that is in the hole.
It goes down in far enough to touch a metal terminal, that is at the end of the wire.
(Approximately 1/2 inch)

The jumper wire of choice is a paper clip straightened out, then bent into a U-shape.
The middle of the U is wrapped a few times with black plastic electrical tape.
(Trivia: One wrap of black plastic electrical tape is enough for 600 Volts DC)

The voltage you will be dealing with is 5 Volts DC.
Two D cell flashlight batteries produce 3 Volts DC.

You may wish to wear a glove on the hand that holds the jumper wire. There may be a small spark.
The Power Supply, (Computer), is plugged into power.

One end of the U-shaped jumper wire, is inserted down into the socket hole with a Green wire. (Right next to the wire)
The other end is inserted down into a socket hole with ANY Black wire.
The contact made is no more than 2 seconds. (1001, 1002)

If the computer comes on, (Power Supply actually), the Power On switch is bad.
If the computer does not come on (Power Supply), the Power Supply is bad.

It's an ATX power supply, probably a generic model made by Bestec, HiPro, Delta, or another low quality power supply manufacturer.
The Wattage is probably stated at Maximum 225 watts.

An ATX style Power Supply is used by over 80 percent of desktop computers out there. You can buy a decent one for around $30 US.
(Power Supply case size is approximately 6 inches Wide, 5.5 inches Long, and 3-1/2 inches Tall)

You can use a 300, or 400, or 500 Watt power supply.
Doesn't matter. Won't hurt the computer.

A computer ONLY uses the power it needs, and no more
Post questions in a Comment.

Regards,
joecoolvette

I also concur that the power supply is at fault.
Weak voltage power rail.

1) You can check the voltages of the power supply with a power supply tester, (One example: http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250576&CatId=1107

2) You can also check the voltages with a multimeter.

There are three main voltages produced by a SMPS.
(Switched Mode Power Supply. However the 3.3 Volt power rail is being phased out)

A) Wires with Orange insulation are 3.3 Volts
B) Red insulation 5 Volts
C) Yellow insulation 12 Volts

D) Black insulation denotes a Ground wire. ANY Black wire is a Ground wire. Granted not a power wire, but needed to be stated here with the power wires.

All power cables unplugged inside the computer, power supply still attached to computer case. Power supply is turned on, and the voltages are checked.

Multimeter is set to DC, and the 0-50 Volt scale if applicable.
The Positive (Red) probe lead of the multimeter is connected to a power wire.
The Negative probe lead is connected to ANY Ground wire.

The Voltage power wire of most concern here is the 12 Volt wire.
11 to 13 Volts is okay. Less than 11 volts it's time for a new power supply.

There are only two different sizes of power supply commonly used that I know of and all power connections are the same as well.
I would suggest a reputable power supply that has specs for each "rail" in amperes not just 500w as there are many pwr supplies that do not "cut the mustard". You can research these in www.tomshardware.co.uk

Easiest thing to do would be to meter out your power connectors, and locate the various voltages that way. Use a multimeter that can read up to 20v DC, and go round the connectors. On most PSU's the black is negative, and the various colours represent the other voltages.

contact emachines and ask them, not all power supply units have volt switches, the best thing you could do is have a physical look at the same model if you can find it in a store or view the specs on line

how did you know that's the problem is on power supply?what signs did you saw before it happened

THIS document has a lot of info about the wiring for the unit you have. starting at page 6

I am, however confused about the voltage requirements as reference to 12/240VAC with a note to check the "rating" plate

If your unit is marked as 240VAC then it should be a simple task for an electrician to wire up the power. The instructions/details are in the manual (link provided) to connect it up as a standard 3 wire system used in the UK

The issue you have is that the motor may not like running on 50hz and may run HOT. It will also run slower on the lower frequency.

The specs on the website are as follows:-

Electrical Requirements
30 Ampere, 120/240 Volts, 60 Hertz (1/second). AC-ONLY. USE COPPER WIRE ONLY. A FOUR-WIRE OR THREE-WIRE, SINGLE PHASE ELECTRICAL SUPPLY REQUIRED. A TIME-DELAY FUSE OR CIRCUIT BREAKER AND SEPARATE CIRCUIT IS RECOMMENDED

It may be worth getting all details off the rating plate and posting back here...

My suggestion is that you consult a qualified electrician before attempting to connect the unit to the power

Better safe than sorry.