Hi Folks,

first off, nice forum you got going there. I'm new to this whole amp fixing thing, though.
Well, lets get to the problem:

My Hughes & Kettner Matrix 100 Head's effects broke down on me. Usually, it forget's the last selected channel and switches to the clean channel.
The clean LED keeps blinking and trying to change the effects or channels won't work. Master Volume still works though.

BUT, when i power down/up the amp several times while holding down all the channel buttons (effects reset), it occasionally works again with a chance
to brake down at any time while playing. That also seems to be the case, when i leave it unplugged a long time and fire it up after that. I contacted a local HK dealer who told me it could have to do with the electronic filter stabilizing the current to the effects circuit board (german term "Siebung"). IMHO, this would indicate a problem with the internal power supply unit.

Why in hell does it work sometimes after the above procedure??
After what i've heard, this is a common problem with this series of amps, but i couldn't find any solutions on the net nevertheless.

Any hints or maybe a service manual would be very helpful. Could it be a bad capacitor or something similar?


Thanks alot in advance for any helpful contributions,
best regards,
MrKnStR

EDIT: I almost forgot, the amp itself is a refurbished one and the problem started after I accidentally left it switched on for two days or so. Maybe that wore parts down, but I can't imagine anything except the capacitors to wear down over time. I never cranked it up to full volume, so it's not a heat/overload issue.