Lenovo IdeaCentre K230

vbimport

#1

Stopped working and suspected power supply failure. Tested PS and it appears OK.
When I short the motherboard connector and power the PS, the PS fan and the chip fan come on and when I push the on button on the computer, an HD that I use for testing comes on. When I plug in the motherboard power connector and press the on button nothing happens.
It appears that something is preventing the computer from coming on. I know that in some laptops, bad memory or no memory installed has the same symptoms, could this be it?
The motherboard appears pristine.
Any suggestions would be appreciated.
Thank you.
chibcharus


#2

I doubt it is the memory because the first thing that happens whe you turn on the computer is the bios code in the eeprom goes through the post (power on self test) procedure. The eeprom will execute regardless of the status of the memory. In fact, part of the post procedure is to check for memory. it will produce a series of beeps if it finds any problem.

Something else is wrong if the power light fails to come on.


#3

I’ve never had a laptop apart so consider that when reading my post.

Let’s start with when any electric connection need to be shorted something has gone wrong . Where ever exactly you are shorting the circuit it is obviously no longer completing this circuit in the normal manor. The short doesn’t do it correctly either because everything doesn’t come on.
The on switch that you are using may have more than one terminal that supplies power to a different location on the MB . So it is necessary for the power to leave both locations & the one “short” doesn’t do this. There may be a “switch” on the MB that the on switch activates . That may also distribute “power” to more than one location .

I would try to find a manual for your computer.
Do the procedure for resetting the eeprom or cmos .
try that & maybe take the MB battery out if it has one.
Maybe the manual will have how long to keep the battery out.
If not at least an hour & maybe a day or two.


#4

I suspect it’s either a problem with your motherboard’s voltage regulator circuit or a faulty power supply…
Can you test the psu on a different computer,instead of on a few peripherals?


#5

Thank you for your response. The computer I am trying to diagnose is a desktop, my question talked about what happens with some laptops when there is no healthy/memory plugged in, it was just for comparison.
I don’t have another computer that takes this type of PS.
I tested the PS according to what I was recommended on line. Short the motherboard connector of the PS and plug in. If the fan in the PS come on and if an attached peripheral turns on, most likely it is not the PS.


#6

Thank you Cholla.
I only mentioned a laptop as an example of what I am familiar with.
I shorted the PS motherboard connector to test it independently from the rest of the computer. This is the first test one does to see if the PS is at least partly functional.
I researched the manuals on this particular computer and there is nothing in them, that I saw, that would help me.
I didn’t test the switch because it is located in a place that is not readily accessible. I will try that next. I will do the same with the BIOS battery.
When I plug in the computer, it is just dead on the water. Nothing comes on. I rerfurbish laptops in my volunteer work and have a fairly good grasp of the works of computers. This one has me baffled. It is more of a challenge than anything else. I am also very stubborn.


#7

[QUOTE=roadworker;2732665]I suspect it’s either a problem with your motherboard’s voltage regulator circuit or a faulty power supply…
Can you test the psu on a different computer,instead of on a few peripherals?[/QUOTE]
roadworker, can you tell me how to test the MB voltage regulator? I don’t have another computer that uses the same type of PS, so I can’t test it. I do have another PS that will fit the computer, and I tested it, with negative results.


#8

Are you testing outside the case? First thing I try when troubleshooting is to remove the motherboard from the case, put it on something non-conductive, and go to a minimal setup. If you go down to one stick of ram, make sure it is in the correct slot for 1 stick in your particular motherboard.


#9

[QUOTE=cpubound;2732652]I doubt it is the memory because the first thing that happens whe you turn on the computer is the bios code in the eeprom goes through the post (power on self test) procedure. The eeprom will execute regardless of the status of the memory. In fact, part of the post procedure is to check for memory. it will produce a series of beeps if it finds any problem.

Something else is wrong if the power light fails to come on.[/QUOTE]
cpubound, nothing happens with I turn on the computer, wish it did. I have to assume that it doesn’t even invoke the pre load processes. What has me baffled is that when I test the PS, any HD connected is powered when I push the on button. I originally assumed that it was the on switch, but the test appears to tell me that at least some of its function is OK.
Thanks.


#10

[QUOTE=chibcharus;2732697]roadworker, can you tell me how to test the MB voltage regulator?[/QUOTE]

I can’t explain that in English,but 1 of my BOOKMARKS can…but you need a multimeter…


#11

[QUOTE=chibcharus;2732699]cpubound, nothing happens with I turn on the computer, wish it did. I have to assume that it doesn’t even invoke the pre load processes. What has me baffled is that when I test the PS, any HD connected is powered when I push the on button. I originally assumed that it was the on switch, but the test appears to tell me that at least some of its function is OK.
Thanks.[/QUOTE]
Check the power block on the motherboard for any bulging capacitors. Also check for bent pins on any connections to the motherboard.

I have to agree with the consensus that the power supply may not be supplying enough power under full load.