Power failure I found my pc powering down just when it is turned on. When I power on cpu ,it is found that for 1 to 2 seconds fan and all other starts working and right the next moment it powers down.But LED on the mainboard remains on

that's easy.
1 beep? you said BEEPS, so tell me its not one beep then leave off how many beeps in a bundle.
1 beep is RTC Coin cell dead. replace. it. page 7 in the manual
2 beep no RAM found
3: beeps. mobo bad. (or?)
4 beeps. 1 ram bad or more. try 1.
5: beeps same as 1 above usually. bad battery for sure.
6 beeps video chip failures. remove card if in PCI-e slot.
7: CPU cache mem. failures, rare but if VRM bad, not rare.
i guess you meant this, ?
Vostro 230 Mini Tower Desktop Computer this is really what it is.
That beep tells you , it sees something very serious wrong.
There are 2 possibles and many tests. do you want to learn?
forget the HDD, unplug it first , focus on FANS first.
both fans, PSU and CPU must run and stay running. my guess not.

• PSU Bad.
• or
• MOBO has overloaded the PSU.

so all tests are to prove 1 or 2. out.
easy no?, a binary choice.
what a tech does next is strip the PC down.
pull out the cards that are in PCI (or express) slots. run now? fans?
pull the power cables from all SATA devices, hdd ,dvd, all.

unplug all USB devices, (overkill but is done for 1 odd case )
test the mobo with CPU in and 1 stick or DDR ram'
only then try each stick of ram 1 by 1.
this is all SOP, standard op. procedures in any shop.
if a module of any kind shorts the PSU sees that and shuts it self off.
the CPU if overheated, too shuts the CPU off, dead saving its own bacon.

if stripped down PC,
just mobo, CPU and any stick of ram makes the PSU shut off
we test the PSU by itself
it that passes the MOBO is bad.
never seen any CPU short ever, VRM's lots.


the power lamp has 5 states of color.
page 7 in your manual if you want to look.
solid blue is normal others bad, black or flashing color.
RTM pg 7.
here it is, at Dell, cost nothing to read.

https://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_vostro_desktop/vostro-230_service%20manual_en-us.pdf

The blinking should be in a pattern.

Power Green On (S0) Computer on
Power Green 1 blink every 2 seconds (S1) Suspend Mode
Power Green 1 blink every 2 seconds (S3) Suspend to RAM
Power Green Off (S4) Suspend to Disk (if applicable)
Power Clear Off (S5) Computer off
Power Red 1 blink followed by 2-second
pause - Repeat
Power Supply failure
Power Red* 2 blinks 1 second apart CPU thermal shutdown
Power Red* 3 blinks 1 second apart CPU not installed
Power Red* 4 blinks 1 second apart Power supply overload (crow bar)
Power Red* 5 blinks 1 second apart No memory
Power Red* 6 blinks 1 second apart No graphics
Power Red* 7 blinks 1 second apart System board failure (detected prior to video)
Power Red* 8 blinks 1 second apart Invalid ROM
Hard Drive Green Blinking Hard drive activity
*Blinking

The fact that ity is trying to start and shuts off after ..it seams that it is the CPU fan to blame ...If the fan fails to start the CPU will turn the computer down instantly due to the temperature limit ..(in 1 or 2 sec ) ..
so ...open it up ..and see if the fan is spinning ...on start ..and if it is not ...check the connection with the board or replace it ..
(by the way ..this may also be a CPU failure ..and need another one ) ..

1 cpu not seated properly 2. memory not seated properly 3. bios corrupted

dont understand properly, there are2 causes one is restarting after showing Win logo - it means your OS has corrupted and you have to reinstall/repair them (first try with safe mode if still same problem then do reinstall)/ second shutting down (power off) while logo showing - it means your CPU Fan is not running or running very slow/ or CPU heat sink not connected properly, any how the problem with in CPU and the Fan check them and problem will resolved.

vote me if found helpful.

Could be one of two most common problems?
#1
Have you ever replaced the CPU Cooler (Heatsink/fan)?
CPU Cooler fan may be working, Heatsink dirty.
CPU is over-heating = mainboard turns off
Replace CPU Cooler
#2
Power Supply fan not working causing partial failure on 5volt or 12volt side.
Replace Power Supply

There are more causes but these are most common for short-time boot problems.
Another could be hard-drive, but that wouldn't shut system down like first two would.

1. First of all Remove dust from your CPU fan and try again if issue has been not resolve

2. Second test your SMPS by the help of Green & Red wire. In case fan is turning properly it mines your SMPS is ok

3. Third & last kindly replace your SMPS For the same.

Hi , here are the codes. listen closely.

Beeps





Error Message




Description
1 long, 2 short Video adapter error Either video adapter is bad or is not seated properly. Also, check to ensure the monitor cable is connected properly. Repeating (endless loop) Memory error Check for improperly seated or missing memory. 1 long, 3 short No video card or bad video RAM Reseat or replace the video card. Repeating High/Low
CPU Either the CPU is not seated properly or the CPU is damaged. May also be due to excess heat.
Check the CPU fan or BIOS settings for proper fan speed.
Phoenix BIOS beep codes

Beeps Error Message Description 1-1-2 CPU test failure The CPU is faulty. Replace the CPU. Low 1-1-2 System board select failure Replace the motherboard. 1-1-3 CMOS read/write error The real time clock CMOS is faulty. Replace the CMOS if possible. 2-x-x RAM failure Replace the RAM module if possible. 3-2-4 Keyboard controller failure The keyboard controller has failed. Replace the IC if possible. 3-3-1 CMOS RAM power bad Replace the CMOS battery or CMOS RAM if possible. 3-3-2 CMOS configuration error The CMOS configuration has failed. Restore the configuration or replace the battery if possible. 3-3-4 Video memory failure There is a problem with the video memory. Replace the video adapter if possible. 4-3-1 RAM test failure System RAM addressing circuitry is faulty. Replace the motherboard.
Good Luck

Mark

dell xps 400 pentium d once i turn it on, it beeps and says "card cage fan failure" everytime i press f-1 to continue it shuts off and boot up again it does it everytime how can i fix this CARD CAGE FAN FAILURE??