Svardskampe
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Keyboard and mouse does not work in desktop [solved]

Wed Sep 04, 2013 4:11 pm

Hey, I have just started fiddling around with it, using raspbian.
Everything seem to work fine. I can use the keyboard without problems whatsoever, just nothing in desktop mode. Everything before typing startx is no problem. Anyone knows what could be wrong?

itimpi
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Re: Keyboard and mouse does not work in desktop

Thu Sep 05, 2013 12:26 pm

The commonest cause for this is insufficient current from the power supply (what is yours rated at). Starting up the GUI increases the current required over that used in console mode.

Svardskampe
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Re: Keyboard and mouse does not work in desktop

Thu Sep 05, 2013 5:30 pm

The official (older model) Asus nexus 7 charger. It's rated 5V and 2A, and is listed in the wiki as a verified power supply. The keyboard I'm using it with is a standard OEM HP keyboard (dt528al) picture and a basic logitech mouse. (B100) picture

mindmasta
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Re: Keyboard and mouse does not work in desktop

Fri Sep 06, 2013 8:19 pm

2 Amps should be plenty (assuming that it is actually delivering what it claims...maybe you should test that!). Both Pi models are rated < 1A.... all you have connected to the Pi are the keyboard/mouse ?

Are you aware of the keyboard shortcuts to toggle the menu once in the Dekstop? Are you sure you're doing the proper keystrokes?

What about the mouse? Are you able to try another one?

Do you have another machine in which you can VNC into the Desktop for now as a workaround until you figure out the problem?

Svardskampe
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Re: Keyboard and mouse does not work in desktop

Sat Sep 07, 2013 1:23 pm

I can't really test the throughput of amps as that would require me to build some kind of meter in between a usb male and female connector. It's not as easy to test out what amps it pulls as it is to test voltage. Don't have these kinds of connectors laying around like that.

What I did notice. Tried with my logitech g500. Booting with the mouse in, did not display anything on the monitor (connected via hdmi). But I left it out and with only the keyboard in, booted LXDE and waited for a quite a long time. (5 full minutes or so). Plugging in the logitech g500, mouse works, keyboard works, albeit everything very skippy and laggy.
The standard mouse still didn't work.

I closed LXDE again and I saw lots of errors like this

Backtrace:

[mi] These backtraces from mieqEnqueue may point to a culprit higher up the stack.
[mi] mieq is *NOT* the cause. It is a victim.
[mi] EQ overflow continuing. 100 events have been dropped.

Backtrace:

[mi] Increasing EQ size to 512 to prevent dropped events.
[mi] EQ processing has resumed after 147 dropped events.
[mi] This may be caused my a misbehaving driver monopolizing the server's resources.
[mi] EQ overflowing. Additional events will be discarded until existing events are processed.

Backtrace:

[mi] These backtraces from mieqEnqueue may point to a culprit higher up the stack.
[mi] mieq is *NOT* the cause. It is a victim.
[mi] Increasing EQ size to 1024 to prevent dropped events.
[mi] EQ processing has resumed after 37 dropped events.
[mi] This may be caused my a misbehaving driver monopolizing the server's resources.
[mi] EQ overflowing. Additional events will be discarded until existing events are processed.

Backtrace:

[mi] These backtraces from mieqEnqueue may point to a culprit higher up the stack.
[mi] mieq is *NOT* the cause. It is a victim.
[mi] EQ overflow continuing. 100 events have been dropped.


I would reckon this would be helpful. Need to google it out.

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mahjongg
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Re: Keyboard and mouse does not work in desktop

Sat Sep 07, 2013 3:44 pm

even with a perfect power supply, there is still a chance the PI (and thus the USB devices) receive insufficient power, I can think of at least three reasons:
  • The cable between the PSU, and the microUSB input connector may be of low quality
  • The polyfuse on the PI (F3) may have been triggered, and is still not completely recovered, causing a voltage drop over the polyfuse
  • Dirt in the microUSB connector may prevent good contact.
Specifically the polyfuse may cause problems, don't suppose it cannot have been triggered! To make sure your power is OK, measure it between test-points TP1 and TP2.

Seems the cause of the problem lies in USB communication failures, and these may be caused by power issues.
Of course it might also be that you have a bad PI, for example if the crystal oscillator on the LAN/USB-hub chip on the PI (LAN9512) "stutters" you might get failures like these. Or perhaps one of the USB connectors has a bad pin.

Svardskampe
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Re: Keyboard and mouse does not work in desktop

Sat Sep 07, 2013 11:11 pm

mahjongg wrote: Seems the cause of the problem lies in USB communication failures, and these may be caused by power issues.
Of course it might also be that you have a bad PI, for example if the crystal oscillator on the LAN/USB-hub chip on the PI (LAN9512) "stutters" you might get failures like these. Or perhaps one of the USB connectors has a bad pin.
TP1 and TP2 give 5.6V to 5.8V when in command mode. As I boot up, my multimeter shows 6V.
Note that I don't trust my multimeter in the decimals. I suspect it measures a good half a volt to 0.8 (maybe 1V) too high.(It monitors a fresh duracell 1.5V battery as exactly 2.00V).

I could exclude the USB cable or dirt, as the pi has been laying around in its box only, and I used different USB cables I charge my devices every day with.

How could I test the crystal oscillator? Or any other tests I could conduct to look at the culprit.


Would be quite a bummer if it turns out I got a bad pi :(, it was one of the first, I believe the first batch of 10K Pis. I just booted it up, check if the leds worked and see if it booted from the SD and it seemed all up to snuff. Since then it had been laying in its box until I set my mind on a pretty cool idea to work out. :/ 2011 it says on the PCB, I believe any form of warranty period has run out by now.
Last edited by Svardskampe on Sun Sep 08, 2013 3:24 pm, edited 1 time in total.

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mahjongg
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Re: Keyboard and mouse does not work in desktop

Sun Sep 08, 2013 12:15 pm

5.6 to 5.8V is far too much, the permitted range is from 4.75 to 5.25V.
Also the PI has a protection device that shorts the 5V supply if it sees, even for a short time, more than 6V. This blows the polyfuse. I suspect your voltmeter is broken and completely unsuitable.

measuring the crystal requires at least an oscilloscope.


one thing you could do, if careful, with a low wattage (15W or less) soldering iron is to re-heat (melt) the solder of the four connection points of the crystal in question X1, don't heat each pin for more than two seconds or so. This has helped others that had non- or badly oscillating X1 crystals. But its just something you could give a try. Make sure your soldering iron is well isolated, and is electrically connected to the PI if its suitability to soldering electronics is doubtful, or you could damage the PI with voltages leaked from mains to the tip of your iron. If you short the voltage with an end of thin flexible wire to the GND of your PI,, for example to the outside of the RCA video plug, or to the metal of the USB ports, or Ethernet port, then electrical damage is unlikely. Connect the other end of the wire to metal of the soldering iron that stays relatively cold.

Svardskampe
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Re: Keyboard and mouse does not work in desktop

Sun Sep 08, 2013 3:22 pm

mahjongg wrote:5.6 to 5.8V is far too much, the permitted range is from 4.75 to 5.25V.
Also the PI has a protection device that shorts the 5V supply if it sees, even for a short time, more than 6V. This blows the polyfuse. I suspect your voltmeter is broken and completely unsuitable.
Well, I already said my multimeter was pretty unreliable for monitoring a fresh duracell 1.5V battery as 2.00V.
mahjongg wrote: measuring the crystal requires at least an oscilloscope.
I don't have that kind of specialized equipment :(
mahjongg wrote: one thing you could do, if careful, with a low wattage (15W or less) soldering iron is to re-heat (melt) the solder of the four connection points of the crystal in question X1, don't heat each pin for more than two seconds or so. This has helped others that had non- or badly oscillating X1 crystals. But its just something you could give a try. Make sure your soldering iron is well isolated, and is electrically connected to the PI if its suitability to soldering electronics is doubtful, or you could damage the PI with voltages leaked from mains to the tip of your iron. If you short the voltage with an end of thin flexible wire to the GND of your PI,, for example to the outside of the RCA video plug, or to the metal of the USB ports, or Ethernet port, then electrical damage is unlikely. Connect the other end of the wire to metal of the soldering iron that stays relatively cold.
As I don't have access to any sort of regulated soldering iron, just a common one which suits for the household needs. (However I'm willing to invest in one if that isn't too costly), the fix of reflowing solder seems comparable to common GPU problems. Have there been people before me succesful in baking the pi in the oven as far as you know? I will google a bit on it as well. EDIT: Found this one http://goughlui.com/?p=160)

Also, are you sure this is the case? Or could it be a different problem? The measures that need to be taken are quite draconian to say the least.


edit: Mystery solved. I suspect my logitech g500 is demanding too much power through the pi. When I was at my parents house I tried using my moms simple USB mouse and I did not get any errors whatsoever.

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