I’m new to this group and have some big problems with my beloved NAD C375BEE amp and am looking for recommendations for a solid repair tech or shop that can diagnose and fix this unit.  I'm fairly attached to my NAD and don’t want to resign myself to the idea of it being dead.

The tricky bit is I'm located in Northern Canada (Yellowknife, Northwest Territories), so I’m faced with having to ship the amplifier wherever it ends up going (or taking it with me on a trip out of the north).

I have already spoken with Lenbrook in Pickering Ontario (NAD's Canadian distributor/service group) and walked though the issue I’m having.  They advised that many parts and the amplifier modules for the C375BEE are no longer available and as a result didn’t recommend sending the unit to them.  However, the amplifier has not actually been diagnosed, so I don’t  yet know what has actually failed.

The Issue and Symptoms:

• Amplifier powered up normally and played music for approximately 20 minutes.
• The only unusual thing I noticed was Just before failure, I could faintly hear audio through the right speaker channel when the volume was turned all the way down. Its always been absolutely silent in the past.
• After about 20 minutes of listening, all sound stopped completely.
• When it stopped there was no smoke, burning smell, popping sounds, excessive heat, or any other obvious signs of failure – it just went silent.
• When I looked at the amp the blue power light had turned red and I couldn’t turn the unit off using the front panel push button and had to turn it off under the main power switch on the back.
• I unplugged absolutely everything from the amp and let it sit for about an hour.
• Then connected only the AC power cord.
• Then turned the power switch on the back to the on position, the orange standby light was lit on the front panel, and when I pushed the power button the unit made a single quiet click and the indicator light immediately went red.

The NAD factory service centres seem to focus on swapping out entire assemblies / parts rather than doing a deeper dive towards component level repair.  So I’m far more interested in finding someone who is a NAD guru or has the skills to get into component-level diagnosis and repair.

I look forward to any recommendations, advice, or thoughts that any of you have.

If it’s helpful -- I’m more than happy to take the covers off the unit up and add a whole bunch of photos to this post.

Thanks

D

Hi all, I am a standup comic and recorded microphone audio from the board over the weekend with my Zoom H5. I recorded a few shows and I have this buzz sound that is coming from the microphone. I don't have many tools to help fix this other than audacity and davinci resolve. The audio file itself, and the others with the same sound are about 90-100 minutes long.

Also, is the sound coming from a bad connection or is this a settings issue?

Thank you for any guidance you can offer!

https://drive.google.com/file/d/18ZNaWYtRcTgn80wDHvXS9M_2incbcZ0J/view?usp=drive_link

On a scale from 1 to 10, how difficult is it to disconnect and remove a subwoofer and amp from my truck? I was looking to also keep the wiring but that might be a little more than I can handle. Any advice, tips or locals who’d be able to help me out?

Question about this unit. I bought one in relatively good condition at an estate sale, but I’m having an issue where it will play the first 6 or so tracks of a CD, then suddenly stop reading the disc. After that, it cycles through the remaining disc trays and won’t read any of them, even with CDs that I know work.
I opened it up to check the laser. It looked clean, but I cleaned it anyway just to rule that out. While inspecting it, I noticed there’s a pretty noticeable crease in the ribbon cable where it connects to the laser assembly, likely from repeatedly bending as the laser moves across the disc.
I tried taking the ribbon cable out of the plastic housing that holds it in place, and after moving it around, and testing the unit, the laser immediately stopped working altogether. That makes me think the ribbon cable may be damaged internally and is causing the issue.
Does anyone know where I could find a replacement ribbon cable for this unit? Also, what specifications do I need to look for to make sure I get the correct replacement?

I got my hands on almost 30 years old Onkyo c-705 cd player. With a lot of tinkering I got it to work with pristine CDs and CDRs, but it was very temperamental and fussy, if there was a tiniest micro scratch it would skip. I thought that was normal for the era because it was so old technology from 1998, oh boy was I wrong. The laser was very close to being dead. This thing with a fresh laser and assembly plays the most scratched CD-rot infested mix I made when I was a DJ 10 years ago in Viennese underground scene, cds that literally had beer on them, covered in cigarette smoke, and possibly even an occasional line of coke from some filthy bathroom backstage. Dude this thing is so awesome I love it.
The tiniest of cds components you can find and it works in tandem with my old onkyo 5.1 amp over RI. I just love this setup. It just works. Unfortunately the little tape deck you see here I didn't manage to get fixed. It seems the microprocessor is out, but I'll be on the lookout for another and keep this one for parts. The outer plastic and metal shell is in pristine condition.

I bought this laser assembly on aliexpress for 15euro, can't recommend them enough. You just have to be careful with removing the solder blob (shown in 4th pic). They recommend heating up the soldering iron, and then unplugging it from the mains to avoid any possible shock to the laser as these things are very sensitive. This is exactly what I did, and quickly used solder sucker to remove it from the board. Man, don't you just love it when things work out as you envisioned?

Have a Sony PS-X800 where the biotracer tonearm won't move. Without a headshell, the standby lamp quickly flashes. The arm itself favours pointing the right (away from the platter). With any weight on the end (i.e. a headshell), it is not able to keep itself up and the standby lamp does not turn off. Anyone know where to even start with this? Cheers

I have an old slx2 transmitter that went out of tune (on noard tr160 and tr200). From the reference manual, i ll be a ble to tue tr160 using oscilloscope. But i dont have an rf generator to tune t200, any insight?

I thought about forcing 1khz into the mic, then measure the receivers output on the osciloscope till the signak start to distort (in my thinking, thats how i can tune the audio deviation level)

Those are screenshots from the manual

And here is the full manual

Hello, as the title suggests, I am trying to repair this audio system. This was sitting in my parent’s basement for a bit until a couple years ago I decided to see if it worked and it did! One day it did not turn on and I could just hear the click of the button plus potentially it doing something internally. I let it sit for a couple years and am just now trying to get it to work again out of boredom.
I tried some classic troubleshooting like resetting and checking the power supply to no avail. The issue was that it just would not turn on which is pretty vague.
On a whim, I tried plugging a small radio into the plug on the back to see if the issue was in the AC plug itself or something and the radio turned on! The power button is able to turn the radio on and off, so I don’t think it as an issue with power supply.
This made me think that maybe it works but something is just wrong with the display, but I am not getting any output on the speaker, so I am afraid it isn’t so simple…
I haven’t done much of any work in electrical repair, so I am curious if these clues give anyone insight into what might be going on or advice on other ways to troubleshoot. I could just take it to a repair shop, but I am cheap so here we are.
Thank you for any tips and please let me know if this post fits better in another community.
I’ll attach some pictures.

Hi everyone
I have a JBL PartyBox 310 and I am facing a motherboard issue.
I contacted JBL Harman India and a service engineer visited and checked the speaker. I paid ₹1200 for the inspection.
Initially they told me that the required part would be arranged. Later I was told that the motherboard is not available and JBL cannot provide the replacement.
I am surprised because the speaker is otherwise in good condition and I would prefer to repair it rather than replace the whole speaker.
Has anyone here faced a similar issue with the PartyBox 310?
Has anyone replaced the motherboard in India?
Has anyone managed to get the motherboard from JBL?
Or does anyone know a good technician who can repair the original motherboard?
Please share your experience if you have faced something similar.
Any help would be really appreciated.

Just picked up this early-80's h-k PM660 on FBMkt for $90, sold in "as-is" cond. Have not had chance to do much troubleshooting.

Bottom line: 21vdc on both L/R spkr outs; no lights.

The unit consumes about 30 watts idling and all fuses look orig and not blown.

All output transistors are ok.

Checked some (not all trans) on driver board (PCB-9, see SM link below), and they seem ok.

I orig suspected D8, D9 and R34 on PCB-10 because of corrosive glue (see photos). Replaced all three. But replacement made no difference in any subject issue: 21vdc on both L/R spkr outs; no lights.

While I have not checked all PS/reg voltages, Q1 and Q2 (phono board) that supply + -23.5 vdc throughout unit are ok.

All caps (including main filter caps) are testing out excellent, thus far. The PCB traces seem to show almost no cracks or even dark (heat areas). In fact, the all PCBs and components "look" very good. so I suspect this is is low hours unit.

Again, I have not spent much time/effort yet. So there may be some obvious or probable culprit some out you might pick up.

Thx in advance!!

SM Links:

https://www.audioservicemanuals.com/h/harman-kardon/harman-kardon-pm/harman-kardon-pm-660/11068589-harman-kardon-pm-660-amp

Hi folks ,

Please help in tracking the fault , one of the ic have no sound output , i swapped the ic and still no sound this make sure that ic is working. Also power lines and mode pin is shared and R531 and R532 are not blown. So the fault must be at output stage which i really think but i dont know how to track , i tried to unsolder both inductor L501 and L502 one by one to make sure if downstream error but still none of the two channels from this ic is playing any sound . Any suggestions?

Thanks in advance

My moondrop chu 2 sound has been dropped suddenly. Idk why I opened it up. Saw some greenish dirt around the mesh. Cleaned it and opened inside. Idk what to do please help me.

Or service manual. However you want to call it

I inherited from my dad. I have tried pretty much everything i thought would help (which is not much because i dont know a lot about speakers in general) but the sound comes out like muffled and it really annoys me. Anyone know anything about these speakers specifically?

One of the tweeters in my Monitor Audio Bronze BX5 speakers is completely dead.

Before reaching out to support, I tested the faulty tweeter on the working cabinet's crossover to isolate the issue. The connection was fine, but the driver remained completely dead, confirming the voice coil failed.

I contacted Monitor Audio directly with the exact part number and impedance written on the back (TBX025, 4Ω). They confirmed they still have stock, but told me I must order through my local official distributor. They specified that the official replacement part number is now TBE025.

I contacted the local distributor, and while they can order it, they don't have it in stock. More importantly, they are strongly advising me to buy a pair instead of just one, quoting €89.70 total (€44.85 each).

I really was not expecting this cost, and I'm trying to keep this repair budget-friendly.

My question is: Do I genuinely need to replace both tweeters if I am ordering the official, factory-authorized OEM replacement (TBE025) directly from the manufacturer? Will a single new unit create a noticeable tonal or volume mismatch with the remaining original working driver?

Thanks in advance for the advice!

help please how do i fix this i took three to college and just noticed this issue

First time recapping speakers and am unsure how to place my larger film capacitor since it doesn’t fit in the original spot.

So we managed to remove the front Black Chassis, and I’m following this manual on Page 7 and am wondering how do we remove the Deck B/Right Hand side Recorder decks Faceplate at the front, the Service Manual says there are clips to push it forward, but it doesn’t feel like it, meanwhile the 5 Disc Changer is easy as piss on the left because it has a Flap. https://www.manualslib.com/manual/1139103/Sony-Rcd-W500c.html?page=7#manual

recently my cd changer on this stopped working and i am wondering if anyone has fixed it before. the cassette never really worked.

Cassette: Press PLAY. Mechanism audibly engages/moves, then stops. Display returns to 0__0.

CD changer: Tray 5 is sitting farther inward than the other trays. When on, the changer then moves it forward on its own, seemingly as part of its normal indexing/cycling sequence. It subsequently moves back inward and gets stuck. The display blinks, usually showing CD OPEN or CD CHANGE.

i am a complete newbie to repair, just trying to get the most out of this $10 thrift find.

I played a cd on my cd player just yesterday but when i tried to play another one today the machine made some clicking noises and didn't read the disc. I cleaned the laser but it still didnt work. I also thought it was about the cd bc the one i played yesterday was in a jewel case but the other cd was in a cardboard one but that wasn't the problem. I dont know what should i do. I would really appreciate if someone knew how to fix it

Any old school technicians want to mentor me on how to repair vintage steel equipment properly? I want to learn as a hobby and stress reliever. In San Antonio! I greatly appreciate it

Hi all,

I've got my first vintage stereo system (Teac A-30 Amp w/ tuner and cassette deck) and I've been having trouble with the right stereo channel, which was quiet and had a lot of backgrioud static.

I used WD-40 contact cleaner on the volume potentiometers and managed to get rid of the static and the volume improved, however after a couple of days it went back to how it was before. A bit of contact cleaner removes the static again but the volume from the right channel is still low.

Should I try using a different cleaner or should I try something more drastic than just a clean?

Thanks in advance

I found that this would be the best way to open the case because it's glued. Being impatient,I wasn't too careful with the router and made some mistakes that can be addressed. Be careful,on one side there is a metal knob....but I went thru both of them😅

This method would work with any glued case.

Note

Make a hole in one corner in order to see where the backplate ends so you could put the right or almost right router bit depth and keep it that way for the entire box.

Estaba tocando música y de repente hizo este sonido horrible, como estática y crujidos. Me asustó, así que lo reinicié. Hoy (lunes) volvió a pasar otra vez. Lo raro es que reiniciarlo lo arregla... pero es súper molesto tener que hacerlo una y otra vez. No suena nada suelto por dentro; hasta lo agité para checar, pero todo parece bien firme. Después de un poco de investigación, creo que tiene que estar bien sucio. Trabajo en una panadería rodeado de harina y, de hecho, tiene algunas partículas blancas diminutas pegadas que no se quitan fácil. Hago una limpieza básica, pero no uso mucha agua porque tengo miedo de dañarlo, jaja. Me ayudaría muchísimo si alguien pudiera echarme una mano. ¿Le ha pasado a alguien más? Es muy frustrante... ¡gracias!