LUXMAN R-1070 (3 fuses blown and faint sound if relay clicks)

[68BStang]

New-to-Me R-1070.

This single owner unit is stuck in Protection Blinking mode with the top 3 fuses burnt.
Now I tried replacing all 3 but it still happened, but randomly the Relay would Click and there would be sound;

Furthermore the R-CH was faint, and when the volume went too high it went back into Protection.
After much time and a second random relay click, the L-CH was perfect, until it wasn't and then resulted to acting and sounding exactly as the R-CH.

What typically causes these issues with this model?

 

[Blue Shadow]

OK

Get the SM from hifiengine, register, log in and download from the Luxman library on that site.
Then determine exactly which fuses are blown
Then folks can start looking at reasons for those to pop and offer guidance on what to check.

How are you at soldering?
Have you got a DMM?

Look into making a dim bulb tester. This allows powering up a blowed up unit maybe even freshly repaired and limits damage if there are problems. Google or ak search a dbt to find out about this device.

 

[68BStang]

OK

Get the SM from hifiengine, register, log in and download from the Luxman library on that site.
Then determine exactly which fuses are blown
Then folks can start looking at reasons for those to pop and offer guidance on what to check.

How are you at soldering?
Have you got a DMM?

Look into making a dim bulb tester. This allows powering up a blowed up unit maybe even freshly repaired and limits damage if there are problems. Google or ak search a dbt to find out about this device.

Thank you for the response Blue Shadow.

I would comfortably say my soldering skills are very good. I have a pro Meter as well, I just don't know how to test/troubleshoot Amps.
Was hoping to find some direction based on my symptoms.

 

[Blue Shadow]

I just don't know how to test/troubleshoot Amps.

Welcome to the club. Even though there is a sticker saying no user serviceable parts inside we all want to jump into the unit and give it a tweak, repair, recap or whatever. Learning electronics is not something done quickly but fortunately there are some friendly folks on ak that will come to our rescue and advise on what to check for and recommend replacement parts when originals are nla.

I'm guessing the fuses that are blown on your unit are F201, F202 and F203 on the board that has the 5 fuses on it. Guessing they are numbered top to bottom, don't know, don't have a 1070 here. Confirming this will let those that can help get an idea of what the next steps to do might be.

 

[68BStang]

[QUOTE="Blue Shadow, post: 16003196, member: 4989"I'm guessing the fuses that are blown on your unit are F201, F202 and F203 on the board that has the 5 fuses on it. Guessing they are numbered top to bottom, don't know, don't have a 1070 here. Confirming this will let those that can help get an idea of what the next steps to do might be.[/QUOTE]

Ok ty again Blue. I appreciate the insight, I'm super new and learning the ropes. I have photos and would love to post them, just need to figure out how. Annnnd just did .

So the pic with the 3 fuses propped up are the blown ones. The second photo is to show what seems like some higher temperature signs, as is pic 3 on the Left and Right Transistors with the metal heat sinks attached (a smaller transistor appeared to be either glued to them, or melted? You can not see in the uploaded image but the original does show 201 and the bottom half of the second two, in 202

 

[Blue Shadow]

Those collars on the transistor pairs are so they heat up the same. Probably part of the bias circuit.

As to your issue, maybe some kind soul will look at this chunk of the schematic and help you search for the problem that causes the fuses to pop.

Please confirm that the fuses are labeled F1, F2 and F3 as those are the ones in the lower left of the diagram. If it was F4 and F5 gonna need a different chunk of the schematic.



The full schematic large enough to read is available on HFE in the service manual

 

[Goldie99]

It may or may not be related to your problems, but the 3 (or 5 ?) gold coloured caps on the fuse board should be checked for any signs of distress (swelling, cracks, etc.), and preferably changed (e.g., C206 & similar). They look to be a known generic problem type after so many years.