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geekhack Community => Keyboards => Topic started by: tsv on Tue, 22 September 2009, 06:20:19

Title: Not enough power for my board?
Post by: tsv on Tue, 22 September 2009, 06:20:19
Hey all,

My IBM Model M13 arrived today from eBay, and I'm having a wee problem. When *just* the keyboard is plugged in, or *just* the TrackPoint, it functions okay, but when I plug them both in it fails to work.

I assume my motherboard is not supplying enough power?

Are there any solutions to this? I assume purchasing a PS/2->USB adapter may well be the best idea, but is there any way I can make sure I'll get one that can handle the power?

Cheers!
Title: Not enough power for my board?
Post by: itlnstln on Tue, 22 September 2009, 10:30:11
Quote from: ripster;119792
First thing to check is whether it works OK on another computer. Another Geekhacker posted a similar problem and 120 posts later it ended up being a power supply issue. (Which we identified around Post 5).

... But it couldn't possibly be my power supply.
Title: Not enough power for my board?
Post by: tsv on Wed, 23 September 2009, 04:32:28
Will try it on my housemate's PC as soon as I'm home later.

I don't quite understand how it could be the PSU, do you mind explaining? Do some only supply a certain limited amount of power to certain ports or something?

Cheers!
Title: Not enough power for my board?
Post by: tsv on Wed, 23 September 2009, 07:47:31
Well it works perfectly on my friend's PC. It stopped working on mine entirely for a while there, but now the keyboard side is fine again.

Do you think the PSU is to blame?
Title: Not enough power for my board?
Post by: itlnstln on Wed, 23 September 2009, 08:09:27
It very well could be.  It might also be a mobo issue in terms of how it regulates power to the USB ports.  You may even want to try a powered USB hub first to see if that helps.
Title: Not enough power for my board?
Post by: skriefal on Wed, 23 September 2009, 08:50:52
He's not using a USB adapter yet.  Doing so may resolve the issue, and should be a cheap experiment.  Perhaps a couple bucks on eBay.
Title: Not enough power for my board?
Post by: itlnstln on Wed, 23 September 2009, 09:17:48
Quote from: skriefal;120008
He's not using a USB adapter yet. Doing so may resolve the issue, and should be a cheap experiment. Perhaps a couple bucks on eBay.

Oops.  That's what I get for skimming the first post.  It's still worth a shot.  Although, if it is a bad PSU, there might be more bad things coming.
Title: Not enough power for my board?
Post by: tsv on Wed, 23 September 2009, 09:37:06
Cheers for the help guys. I'm hoping to have a new PC in a few months so for now I'll try and get my hands on a USB adapter and hope. Will report back!
Title: Not enough power for my board?
Post by: itlnstln on Wed, 23 September 2009, 09:53:23
It might also be that the 5v rail (someone correct me if I'm wrong) in the PSU might a little underpowered. Most newer BIOSs will have a screen that shows the PSUs output on the different rails.  If you're handy with a screwdriver or two, you can open up the PSU case, and adjust the pot for the appropriate rail.  Do it in VERY small increments (you don't want to give it too much gas, or you might fry something) and check the rail in the BIOS.  I used to set my rails between .1 and .3v higher than the rail value (so my 5v rail was putting out 5.2v, for example).  This might fix your problem, too.
Title: Not enough power for my board?
Post by: timw4mail on Wed, 23 September 2009, 12:45:11
Quote from: itlnstln;120016
It might also be that the 5v rail (someone correct me if I'm wrong) in the PSU might a little underpowered. Most newer BIOSs will have a screen that shows the PSUs output on the different rails.  If you're handy with a screwdriver or two, you can open up the PSU case, and adjust the pot for the appropriate rail.  Do it in VERY small increments (you don't want to give it too much gas, or you might fry something) and check the rail in the BIOS.  I used to set my rails between .1 and .3v higher than the rail value (so my 5v rail was putting out 5.2v, for example).  This might fix your problem, too.

Quote from: ripster;120051
Show Image
(http://lc.fdots.com/cc/lc/d1/d1d0423803bab645dd361e8ea06b62ea.gif)


Discharge the caps properly first.  Simple way is to pull the plug and hit the power button.  Safest way is to put a resistor over the +/- of the caps or a screwdriver if you like fireworks.

I sure wouldn't be trying that. Buy a reputable PSU, and you shouldn't have to worry about such possibilities.
Title: Not enough power for my board?
Post by: itlnstln on Wed, 23 September 2009, 13:33:33
Quote from: timw4mail;120052
I sure wouldn't be trying that. Buy a reputable PSU, and you shouldn't have to worry about such possibilities.

I have used Antec, Enermax and other "good" PSUs that have had the rails set incorrectly.  It's not a quality issue, it's just a settings issue.  That said, if you don't have a quality PSU to start with, then you're just pissing up a rope.
Title: Not enough power for my board?
Post by: Rajagra on Wed, 23 September 2009, 13:42:02
Quote from: ripster;120053
Wha.....?  You're no fun.
Show Image
(http://images.needcoffee.com/do-not-lick.jpg)

Better use the correct tool to be on the safe side...

(http://www.thinkgeek.com/images/products/zoom/vilcus_plug.jpg)
Title: Not enough power for my board?
Post by: 1839cc on Wed, 23 September 2009, 13:49:15
Quote from: Rajagra;120069
Better use the correct tool to be on the safe side...

Show Image
(http://www.thinkgeek.com/images/products/zoom/vilcus_plug.jpg)
LOL. Where can I get one of these?
Title: Not enough power for my board?
Post by: Rajagra on Wed, 23 September 2009, 13:49:37
Quote from: ripster;120071
I don't know how you Europeans survive that 220v stuff.  I've gotten 110v before and that was enough for me, thank you.

It's the volts that jolts, but the mils that kills.

Quote from: 1839cc;120072
LOL. Where can I get one of these?
http://www.thinkgeek.com/stuff/41/lebedev.shtml
http://www.artlebedev.com/everything/vilcus/

In all honesty I can't tell if it's safe to use, or a Darwin Award device.
Title: Not enough power for my board?
Post by: roaduck on Wed, 23 September 2009, 14:00:36
As I understand it - current (amount) in amperes is more important than voltage (speed).8 MN1500 alkaline batteries have the same potential difference (ie voltage between the anode and the cathode) of a 12v car battery but the sealed lead acid battery with ten 1.2v leclanche cells in series have much more current than the penlight batteries.
The first thing I look for in a computer PSU is over-regulation and high current.

I had a few problems with power supplies on my first three computers.The first was a Patriot that had a psu that shorted and produced blue sparks on insertion and extraction.I put it in a new case with a cheap PSU and promptly sold it.The next had a 350w which I upgraded to 550w.My last home-built power supply unit had the original frame transformer replaced with a round emf-shielded,eddy-current stabalised toroidal transformer that gave out the same 600w as the original but had ten times more amperes on tap.With a constant bias voltage (class a) there was no need for a switching circuit and it worked like a dream apart from the fan had to be upgraded to a mains alternating current 230v unit to cool it.
Title: Not enough power for my board?
Post by: itlnstln on Wed, 23 September 2009, 14:03:13
Quote from: Rajagra;120073
It's the volts that jolts, but the mils that kills.
 
 
http://www.thinkgeek.com/stuff/41/lebedev.shtml
http://www.artlebedev.com/everything/vilcus/
 
In all honesty I can't tell if it's safe to use, or a Darwin Award device.

Definitely the latter.
Title: Not enough power for my board?
Post by: 1839cc on Wed, 23 September 2009, 14:14:45
Quote from: Rajagra;120073

http://www.thinkgeek.com/stuff/41/lebedev.shtml
http://www.artlebedev.com/everything/vilcus/

In all honesty I can't tell if it's safe to use, or a Darwin Award device.
Makes a great gift...
Title: Not enough power for my board?
Post by: Rajagra on Wed, 23 September 2009, 14:18:17
Is that rock USB 2?

I always buy PSUs with a switch on the back. Not only is it a sign of quality, but I never forgot a friend's story of when smoke was pouring out of his PC and he couldn't find a way to quickly power it off. (I think it was too close to the wall to yank the cable out.)
Title: Not enough power for my board?
Post by: roaduck on Wed, 23 September 2009, 15:05:39
Thinking back I wouldn`t build another linear PSU for a PC.It was expensive (£500) in parts alone mainly for the 3.0 KVA toroidal transformer, 4 x 400,000 microfarad capaciitors and full-bridge rectifiers,they are very inefficient,get very hot and acoustically noisy (with a 200mm A.C. fan) and 12" aluminium cooling fins.Plus they are heavy and huge - 24" x 18" so they have to be external and painted in matt-black exhaust paint.The best thing was very low ripple current and electrical noise coupled with high-regulation made it good for isolation from sensitive internal digital circuits like the DAC.
Title: Not enough power for my board?
Post by: JBert on Wed, 23 September 2009, 16:21:10
Quote from: ripster;120088
I've got 4 of these suckers - 3 in computers and 1 as a spare.  (I had an OCZ go bad on me once on my wife's computer.  She was not happy.)
Show Image
(http://www.techcomputers.pt/loja/images/Silencer_750_Red_3827.jpg)
Heh, should your computer explode, you can still find the shrapnel from your PSU in all the wreckage. And I wouldn't want to transport one of those by air though, some people may start thinking the black box got unplugged.

Anyway, 750W should be enough for everyone. I got a CoolerMaster 700W Silent Pro and I must say I can't complain. Decently efficient in most power ranges and nearly silent to boot.
Title: Not enough power for my board?
Post by: rdh on Wed, 23 September 2009, 21:01:17
Quote from: Rajagra;120073
In all honesty I can't tell if it's safe to use, or a Darwin Award device.


Safe to use?  For very loose definitions of "safe" and "use", maybe, provided you're using one hand, not grounded, and willing to ignore burns, sudden involuntary muscle contractions, nerve damage, etc.

If you want to try for the award, simply use one finger from each hand.  No grounding required!

Quote from: Rajagra;120073
It's the volts that jolts, but the mils that kills.


Sing it, brother!

Put enough current through your heart and lungs (it doesn't take much), and you're outta here.

I had a professor who was fond of claiming that you could kill yourself with a D-cell.   He recommended sanding the skin off the inside of your wrists, rubbing lots of salt into the wounds to improve conductivity, then holding the battery so that the positive terminal contacted one wrist and the negative terminal the other.  

Who knows, it might even work.  But you'd have to be really determined.
Title: Not enough power for my board?
Post by: Rajagra on Thu, 24 September 2009, 14:53:23
Quote from: rdh;120176
I had a professor who was fond of claiming that you could kill yourself with a D-cell.   He recommended sanding the skin off the inside of your wrists, rubbing lots of salt into the wounds to improve conductivity, then holding the battery so that the positive terminal contacted one wrist and the negative terminal the other.

When at school I connected a battery to a transformer via a switch that *disconnected* the power. I wired the output of the transformer to the surface of the switch. Boy, did people jump when they pushed that button.! :evil:

LOL I just noticed the rating on that device: 10A 250V. Good to know they didn't skimp on the spec. :lol:
(http://www.artlebedev.com/everything/vilcus/vilcus-eu-plugged.jpg)