# Solved: Keyboard lights blinking



## Kortai (Jun 11, 2006)

I was playing a game, my system crashed to the point of the power shutting down. I could not turn the power back on immediately.

The keyboard that was in my system is now destroyed as a result. The lights on the keyboard blink repeatedly. This has happened twice now. Both times the keyboards were destroyed. Trying the keyboards on another computer did not solve the problem.

I haven't played any memory intensive games since the second crash, because I do not know if it was specific to the one game, or if I would destroy another keyboard.....and keyboards are starting to get expensive.

I have two questions, first is, anyone have any ideas on what caused the crash?

The second is, is there any way to reset the keyboards?

Thanks.


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## qldit (Mar 18, 2005)

Good Evening Kortai, that is an interesting problem, actually most motherboards will have a fuse involving the keyboard power line but these are not generally user replaceable.

As you are aware PS/2 and USB keyboards are a little different, I suspect you are describing a PS/2 type.

I imagine you have confirmed these keyboards are inoperative by trying them on other machines. 
This problem should not happen.

This problem should not normally be caused by a motherboard defect but it is possible it could be, especially if the electrolytic capacitors were dry.
Check www.badcaps.net for inspection method.

The most likely cause of this problem is the PSU with high voltage rails.

I dont believe it can be caused by any softtware or memory circumstance.

If you can obtain and run a copy of Everest Home analysis program it may give a clue in the sensors page. I dont have the URL for thr older free copy handy, you will need to look for it.

qldit.


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## Kortai (Jun 11, 2006)

Thank you,

I haven't opened the box yet to check and see if the cps are bad yet, but I want to know if replacing the power supply could fix this problem? Assuming the caps aren't bad.

While I am using PS/2 keybords I had to buy a usb converter, as the PS/2 port is now dead.

Actually, right now I'm using the on-screen keyboard......


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## qldit (Mar 18, 2005)

Good Morning Kortai, I would be inclined to inspect the machine and try to determine what the voltages are before getting further involved with replacing components.
You need have an idea of what the voltages actually are.
This is like war, you need intelligence from the battlefield to form an address idea.
qldit.


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## Kortai (Jun 11, 2006)

Field	Value
Core Voltage	1.50 - 1.65 V
Field	Value
I/O Voltage	1.6 V
Field	Value
Typical Power	44.0 - 64.0 W (depending on clock speed)
Field	Value
Maximum Power	48.5 - 74.3 W (depending on clock speed)


All values are from everest......

Field	Value
CPU	21 °C (70 °F)
Field	Value
Maxtor 4R080J0	42 °C (108 °F)


I'm starting to think overheating is the problem.

Oddly, under chipset, south bridge.......Field	Value
Core Voltage	2.5 V


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## qldit (Mar 18, 2005)

Good Morning It seems the voltages that would be more inclined to be in error are not displayed for you. Some boards don't have many sensors to allow this.
Yours appears to be one of those, always the case when you need it, you don't have it!

The voltages I would have been more interested in would have been the +12 volt and +5 volts.

I can't explain why the keyboard LEDs are flashing. 

Are you familiar, and do you have a meter that you might use to measure the voltages on one of the drive power lead plugs? 

If you do, use it to measure the actual voltages on one of the plugs.
The voltages are both DC and when measuring the four wires in them, expect +5 volts on the red and black pair and +12 volts on the yellow and black pair.
These pairs are from the outsides of the plug and black is negative.
Hopefully your wires will be this same colouring. 

That CPU temperature looks odd, surely it can't be that cool!

Is there any possibility these keyboards were the same and may have had some kind of inherent problem?

The only other suggestion would be to get a cheap USB keyboard to use as an interim measure until some kind of reason might be found.

Sorry not much help.

As I mentioned I am suspicious of that PSU but it needs to be checked before replacing it.
The simple PSU testers might be helpful but they are pretty basic.

qldit.


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## Kortai (Jun 11, 2006)

As a general rule, I am no good with hardware issues. Manually testing the PSU is beyond me. I purchased a PS/2 to usb converter so I can use any keyboard.

Could it be that the PSU gives a slight power surge when it crashes, that is killing my keyboards? It has also burnt out my first PS/2 to usb converter....

Could that reasonably explain everything?


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## Rumpo-Stiltskin (May 9, 2006)

"eMachines" are legendary for having suicidal power supplies (not that the rest is usually anything to celebrate).
It's either that or the motherboard, but i'd go out on a limb and say just get a new power supply, otherwise there may not be anything left to save soon.
If it's the standard PSU that came with the machine then it needs replacing anyway.

Try something from: Antec / Seasonic / Fortron / Sparkle / Thermaltake etc. (or any other good, branded supply).

Unless of course the existing power supply or case is a non-standard size, which may necessitate the adoption of a new case as well.
It could get complicated...........

--------------------------------------------------

Link for you:

http://www.consumeraffairs.com/computers/emachine_power.html


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## Kortai (Jun 11, 2006)

As it turns out, the situation was indeed due to bad caps.

I had to replace not only the motherboard, but also the hard drive. Everything is working fine now.

Thank you.


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## qldit (Mar 18, 2005)

Good Morning Kortai, it seems that we can do all kinds of incredible things except make reliable simple capacitors.
It is scary isn't it!
This problem is ongoing and common, almost as if it were accepted norm.
Nice to hear you sorted it out.
Cheers, qldit.


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