Just a shot in the dark here. I have a Luxman F-105 with no audio output. There is a blown 1/4 watt resistor near a voltage regulator which I suspect is the cause. The markings are burnt off so I have no way of telling what the value should be. Oddly it's in series with a 2 watt 12 Ohm resistor . Would anyone here have access to a service manual for this piece ? The resistor number on the board is R809. See pic for an idea - the 2 watter is the one beside the regulator and the blown resistor has been removed . TIA for any help. Mike.
Attachments
There is an AV-amp F-114 on the HIFIengine, but models can differ tremendously.
R809 can be in series with the 12Ω/2W resistor, but I guess there is another branch going elsewhere from this resistor to supply other parts of the circuit. R809 is for a separate (less current consuming) branch, and something is broken there. It can be an output relay or a mute circuit just to name two.
Can you clearify what this F-105 is actually (pictures of front and rear may help).
R809 can be in series with the 12Ω/2W resistor, but I guess there is another branch going elsewhere from this resistor to supply other parts of the circuit. R809 is for a separate (less current consuming) branch, and something is broken there. It can be an output relay or a mute circuit just to name two.
Can you clearify what this F-105 is actually (pictures of front and rear may help).
Last edited:
That resistor is likely to be only a symptom, the real problem is probably elsewhere.
I did try, plenty on LV-105 /F114 but only one with the F105 service manual but it costs.
Its a pity the markings are burnt off the regulator ,sometimes shining a light at an angle can make out faint markings.
In 1984 Luxman was sold to Alpine Electronics who changed the name to Alpline so if the F-105 is round about that era then I can understand why its hard to get a schematic.
The new company went downmarket selling to Costco (USA) and didn't make it -sold off in 1994 which enabled their reputation ( Luxman )to be restored.
Its a pity the markings are burnt off the regulator ,sometimes shining a light at an angle can make out faint markings.
In 1984 Luxman was sold to Alpine Electronics who changed the name to Alpline so if the F-105 is round about that era then I can understand why its hard to get a schematic.
The new company went downmarket selling to Costco (USA) and didn't make it -sold off in 1994 which enabled their reputation ( Luxman )to be restored.
I meant the resistor is unreadable and definitely open. I suspect there is a lot of heat from the regulator and that may have caused the eventual failure of the resistor. Of course there may be another problem elsewhere but it's simple enough to plug in a new resistor of the correct or near enough value and see what happens. It appears the resistor slowly failed as it's still in one piece but the paint is pretty much gone. The worst that can happen I suppose is it will fail again or it may just work. When I put a new one in I'll put some insulation on the leads and position it further from the regulator. Here's a video of a 105 in operation. Luxman F-105 Surround Sound Amplifier / ADS L520 Speakers - YouTube
In mine all the readouts and indicator leds are working, the master lineout volume control works. The f105 basically takes a stereo input and emulates a 5.1 system with dolby and delay - it has a center speaker O/P and a left right rear speaker O/P . It can also control an entire luxman system from just the F-105 remote and do all the functions of an AV receiver. It has i/ps for cd, tuner, tapes video etc.
In mine all the readouts and indicator leds are working, the master lineout volume control works. The f105 basically takes a stereo input and emulates a 5.1 system with dolby and delay - it has a center speaker O/P and a left right rear speaker O/P . It can also control an entire luxman system from just the F-105 remote and do all the functions of an AV receiver. It has i/ps for cd, tuner, tapes video etc.
Did a bit of tracing and the bad resistor is connected to the 2 w 12 ohms resistor which is connected to ground via an electolytic cap. the other side of the bad resistor is reading 34 V dc which connects directly to a 1/4 w 100 resistor which is dropping 2.4 volts and connected to a 15k resistor . From there I can't see where it goes . The volt reg is a 78M09A and I'm not getting much from it - in the fractional volt range . The regulator obviously is a 9 volt rated at 500 ma. That's where I'm at now. Not going to put too much effort into this as it's more than it's worth but if I can get a value for the bad resistor I'll try that and if it flies, great. Otherwise it goes out as a parts unit. Thanks for the help so far. Mike.
