hifi engine

Luxman L-100 schematic needed


I'm restoring my dad's Luxman L-100.
I stumble upon something strange. R933 keeps burning away when I renew it. The original one was also burned. The strange thing is that it has always functioned well. Only it's last days were a bit less. The description sounded " sometimes you hear a big bang out of the speakers, and sometimes it will go into protect".
I would like to know if someone has a schematic or better, a service manual ?
Or maybe an experienced person can give me a hint, if this sounds familiar ?

Thanks in advance

Well, here it is:

Caffrox, One thousand times thank you!

This big boy (l-100) is alive and kicking like new (!)
All specs are fine and it sounds so darn fresh again :-)
It has been cleaned inside out and almost looks like new.
Though I don't need it at all, I just love to get new life in "beasts" like these.
Shiny again and she's lurking for a new owner. I've had some people already with interests.

Now I'm starting on a Pioneer sa9900. I've done the tuner (tx9500) already and it is funny that with a complete
recap those machines sounds soooo much better than nowadays "rubbish". The ctf-8080 cassette deck is also there,
so that would make a very heavy three component stereo :P

Best regards !

Luxman L100

It is for sure not a job that you do in an evening .... or a day. :)
But, it's alive again, and how !
I have replaced every capacitor, and cleared all connectors too.
put in one PA channel, was ok, second PA channel also ok ..... but ...
I have replaced r933. It doesn't look nice, a burned resistor.
Can someone tell me why this darn thing will go up in smoke every time ???
Or do i have to speak with that big relais ? :p
(read: everything that can burn will be burned of r933 untill there nothing to burn anymore)
Fun thing is that it's value doesn't change (around 560ohms).
1/2 watt it says ..... i'd love to put a watt in there but maybe this sounds familiar.

It's not always a short that smokes
resistors stink when hot

Luxman l100 resistor r933

Hi sorscha. It was odd i was looking for some info on the exact same problem. on the power board PB647. resistor r933 gets hot and burns all the color code of it. i did the same Changed all caps on there. would like to no Did you fix it. Im looking in to changing the relay transistor Q913 also Q910 witch is inline with the resistor in question.
Any help would be great.
Do like the big luxman l100

Luxman L100 restored

I forgot to mention that I made several photos's during the process. I have it described at my site.
Though it is not available in pdf yet, the html is there.


The story hasn't been finished ... yet

Luxman L100 board 647

Hello mr. Leach,

I think you should check all the transistors there. Q910 and q913 were the culprit at mine. I also noticed very strange behavior when I was 'moving' the board when powered on. I then found broken pin solder joints (!)
Also ... as this wasn't all ...
Reflow every solder joint, and reflow every pin (where the wire-wraps go). Wire-wrap is one of the most bad things
used in amplifiers (I really hate them ) The solder joints are very prone to corrosion because the pins are not secured. I found several 'loose' pins which I could pull out without any effort. Reflow ! (the whole amplifier).
Big, big job , but it pays of giving you a smile from one ear to the other :)

Luxman L-100 schematic needed

It seems you are right,
But i had to use a more modern computer. There i got a timer :)
I use an old unix box with probably an outdated internet browser.
But i got it !
Thanks! Now i know where the culprit is :)

It's not always a short that smokes