Hello everyone, I'm new to the electronics repair hobby. I could not afford a Luxman M-117 so I purchased a broken one and figured I would try my hand at repairing this one. So here goes.... The right channel has -74 volts DC at the speaker terminals all of the output transistors are showing the same -74 volt on the emitter leg. Should I remove all of the output transistors and test? I have attached a service manual. Any help would be appreciated?
-
-
Re: Luxman M-117 amplifier
Look at the bright side. You got a working channel and a non working one. With amps I work backwards. So check the finals first and you also can swap from side to side. It also could be the driver or the pre-driver. Look at the block diagram on page 6. In the final stage there are large 0.22 ohm 2w resistors one for each transistor, check those too if they went open.Last edited by CapLeaker; 08-31-2022, 02:30 PM. -
Re: Luxman M-117 amplifier
Cool, thanks for the pointers. So if any of those resisters goes open it would cause this condition?Comment
-
First off I would like to thank this community as it has provided me with great information that has helped me greatly on my repair for this Marantz SR5012 AV receiver. I am creating this new thread as the other 2 that I have created here has had their original question/problem solved and I plan that this is the final thread on my repair. Please note that this is my first time repairing audio amplifiers so I may not be aware of common issues and things to know.
Lets start at what I have done so far. Random speaker popping on all channels is fixed by replacing the 2 large filter... -
Hi:
I've realized that one of the channels of this amplifier has no proper sound.
This is the signal at the speakers output.
As long as the audio coming in to the amplifier board (blue) looks ok although with some noise due to the wire, I think that there's nothing to look at the preamp section.
Now, I could start looking at components to see whether I find the guilty one.......but I would rather prefer to ask for advice. Here there is the amp. schema. Which points would you check with the oscilloscope to gather... -
So like the title says, I have an old Stereo Receiver/Amplifier that I picked up from the goodwill, it's a HH Scott Model A510. When I first got it home it had zero output. Opened it up, notice the fuses are missing. Pop in 2 new fuses (AGC4A 250V) and try again, within 5 seconds the L channel fuse POP! I don't see any visible indications of damage or arc burns on the PCB, no popped resistors or diodes, no burnt traces or blown out caps. So I decide to just try another new fuse, POP. Swapped around my R and L speaker wires, and checked the integrity of all wires and connections. Everything looks... -
Anyone run memory speed tests with an old X58-based triple channel 1st gen or any other >2 channel board? The one I have is a Gigabyte I think.
Anyway I had four 4GB DDR3-1333 modules in the 6 memory slots and got around 11GB/sec memory speeds assuming that it went dual channel since it didn't have enough modules for triple channel. Now I stuck in two more 4GB modules, but they are DDR3-1600. I'm still getting 11GB/sec speeds according to memtest86...
Just wondering, anyone do memory speed analysis on these triple (and higher) channel memory boards? Are there any... -
Hi guys
I'm trying to repair this powered mixer. Sorry this is a bit long but I want to give as much info as possible to help get an answer,
As soon as it powers on the protect light comes on. There are relays that connect the speakers to each channel of the amplifier but they never click. If I connect a 60W light bulb in series with the mains supply it comes in bright then goes to maybe 30-50% brightness - it seems to dim a little further over time
I have power to the amplifier, I think it was as about plus/minus 50-60V for the main amp, and plus/minus 15V...
Comment