I just know there is a simple solution to this.
I'm trying to link an electric guitar to Hydrogen and Rakarrack using QJackCtl - but I am getting no sound from the speakers.
So far:
1. Guitar into Mic or Line input on Mobo - get sound out
2. Playing CD's - get sound out
3. On-line: Videos, Music, Radio - get sound out
4. Hard drive MP3's through VLC Media Player - get sound out.

QJackCtl, Hydrogen and Rakarrack all installed correctly and appear to link up OK - in accordance with the Help files offered by Rakarrack, Hydrogen and QJackCtl. When I start a Hydrogen sequence, QJackCtl indicates and follows the same time-line.
There appears nothing wrong in the QJackCtl log.
In QJackCtl - Hydrogen automatically links its OUT channels to QJackCtl PLAYBACK Channels.

I'm running Mandriva 2009.1 with a Core 2 Duo E7300 CPU on an ASRock P43Twins1600 Mobo using the onboard Intel HDA Audio.

I've run through the normal Mandriva sound check i.e.
"lspcidrake -v | fgrep -i AUDIO" - finds snd-hda-intel as the driver
"grep sound-slot /etc/modprobe.conf" - returns: alias sound-slot-1 for the snd-hda-intel driver
"/sbin/lsmod" - Ok but not entirely sure what I am looking for here
"/sbin/chkconfig --list sound"
sound 0;off 1;off 2;on 3;on 4;on 5;on 6;off 7;off
"/sbin/chkconfig --list alsa"
alsa 0;off 1;off 2;on 3;on 4;on 5;on 6;off;7 off
(Aside - replaced all colons in above for semi-colons as for some reason colons ( are interpreted as images and I'm only allowed 8 images ??? - but I digress)
"aumix -q" : command not found (probably because I'm using alsamix or Kmix)
"/sbin/fuser -v /dev/dsp" : no response

So where do I go from here? In response to several searches I've tried running with pulseaudio on and off (with reboots) and still nothing. Is there a simple command line check on the QJackCtl app which will see if anything is getting to this point as I believe that this is where it is alll falling over.

With much thanks for any help
Colin

Since I'm not familiar with Mandriva and have not used PulseAudio, I can't offer much detailed advice, but...

If it's a problem with how jack is configured, just route the input to the output in qjackctl and see if you get any sound simply passing through. Make sure your jack configuration includes the proper input/output devices. Sometimes you'll have a sound card chip on the board that isn't actually connected to anything, or more often, a chip that supports more inputs and outputs than what are physically implemented on the circuit board (so your sending audio to a pin on the chip that isn't connected to anything). Sometimes the problem can be corrected by simply changing the hardware devices that jack is using.

It's a stab in the dark, but it's worth experimenting with the different devices you have available in the configuration utility in qjackctl.

Well - I've got it to work but I don't know why or really how.
I saw a Mandriva Forum item on "No sound after resume from suspend" which
contained the following - and as I was getting a bit desperate - I tried it -
killing things seemed a good idea.
# Killall pulseaudio
# Killall kmix
# /etc/init.d/alsa restart
# /usr/bin/pulseaudio --daemonize --log-target = syslog
# /usr/bin/kmix

The final two lines didn't seem to work - threw up the following:
<unknown program name>(24948)/: KUniqueApplication: Cannot find the D-BUs
session server
<unknown program name>(24947)/: KUniqueApplication: Pipe closed unexpectedly
So left these out.
Occasionally I get the following after the # /etc/bin/alsa restart

WARNING: Module snd-mixer_oss already in kernel
But Invoking Aumix seems to cure this - don't know why.

Anyway - the outcome is that I now have Electric Guitar linked to Rakarrack
with all its effects and have Hydrogen providing the drumming background -
Success - but the wife and neighbours now hate me.

It looks like pulseaudio was messing things up. If the last two failed, then that means that pulseaudio did not come back up, but you do have alsa. Jack is friendly with alsa, but I have seen a number of places where pulseaudio stomps on jack, or vice versa. I'm guessing the problem is that alsa owns the hardware, and pulseaudio and jack both want to take complete control of the device presented by the alsa drivers. In this case, it's one or the other.

I'm not sure how development is going with this, but jack needs to be started as a client of pulseaudio, or vice versa.

I'm glad you got it working! Enjoy annoying people with loud noises...although it doesn't require a working FX program to do that. My guitar amp on its own can turn the neighborhood into a party.