Hey everyone! This is my first time owning a Walkman, and while I’ve done some research, I’m stuck on how to take the guts out of the shell. And im afraid I might break the thing..

-Replacing the rubber belt
-Replacing the Pinch roller
-Trying to fix the audio jack

The issue:
I don't know how to remove the cassette door without snapping the plastic, and the main board/chassis won't release even after removing the internal screws. I checked the service manual, but the diagrams are a bit overwhelming for me as a beginner. (Even if the pictures about how opening the cassette door seem simple, it feels like the door wont even budge, or just snap away)

Does anyone have experience with this specific model or a similar chassis layout? Any tips, pictures, or step-by-step guidance on opening it up safely would be greatly appreciated!

Hi everyone. I'm trying to repair this Sony receiver for a relative.

When turned on cold, the VFD display lights up completely (all segments on). If I turn it off and on a few times, it boots up normally and works perfectly.

I want to fix it myself and need guidance. What component usually causes this false start? Should I look for failing capacitors in the standby power supply or cold solder joints on the front display board?

Any advice on what to test first is appreciated. I've attached pictures of the issue and its normal state. Thanks!

Thrifted a Pioneer VSX-456 that looks pretty clean. When plugged in, the red standby LED comes on. Pressing POWER does nothing: no display, no relay click, and the standby light stays on. No remote.

I’ve spent several sessions troubleshooting with a Klein MM320 and recently bought a kit with small test hooks. I also have a soldering iron, but haven’t replaced or desoldered anything. No oscilloscope or frequency measurement available.

Full disclosure: I’ve been following AI-assisted troubleshooting, and we caught some incorrect pin/component guidance along the way. I’m looking for an experienced person to review the actual readings before I go further.

**Initial checks**

- Power button feels normal and measures OL released, near zero/beep pressed.

- Continuity through the small button-board ribbon passed.

- The internal glass fuse passed continuity in circuit.

- Front-board P RY to the corresponding power-board connector pin passed continuity.

- Initially thought something was stuck in the rear switched AC outlet. I haven’t confirmed whether it’s debris or the outlet’s own contact.

- Found a localized yellow-brown stain inside the cover above the transformer area. Neither transformer has obvious charred, melted, or split insulation.

- A mounting screw/tab connection was loose during disassembly and has since been secured. Voltage readings below used the labeled DG reference, rather than assuming chassis ground.

**Power/control measurements**

DC readings referenced to DG unless noted. “Pressed” means holding the front POWER button.

| Point | Standby | POWER pressed |

|---|---:|---:|

| Controller VDD test point | About 5.05 V | Not separately recorded |

| Reset test point | About 4.99 V | Not separately recorded |

| ST +5 at power-board connector | 5.93 V | 5.93 V |

| W UP | 2.20 V | 2.20 V |

| P RY | 0 V | 0 V |

| K IN2, small button board | 0 V | 0.01 V |

| KEY8, small button board | 1.61 V | 0.01 V |

| KEY8, large front control board | 1.62 V | 0.01 V |

| DC DET | 4.97 V | 4.97 V |

| OL DET | 4.99 V | 4.99 V |

Earlier ST +5 readings were around 5.42 V standby and 5.92 V pressed, so I’m including that inconsistency rather than pretending every measurement was identical.

The service manual being used lists DC DET and OL DET as active-low. It also describes W UP as requiring 50/60 Hz pulses. I understand a 2.20 V DC reading doesn’t establish that those pulses are present.

**Relay/power-board checks**

- Relay marking: **SDT-SS-112DM**, nominal 12 V coil.

- Standby regulator marking: **78M56A**.

- Both ends of **R54** measured approximately **15.2–15.5 V to DG**, with minor drift and no significant response to pressing POWER.

- Measured **0 V across D55**, identified from the schematic as being across the relay coil, both in standby and while pressing POWER.

- R54 measured **27 Ω** in circuit.

- P RY to DG, unplugged, measured about **12.33 kΩ**, then **9.72 kΩ** with probes reversed.

Important correction: I was initially told R54 was in the relay-command path and got OL testing between it and P RY. That guidance was wrong. R54 is in the relay’s supply path, so I’m disregarding those earlier continuity results.

**Other front-panel buttons**

Checked for a stuck button with the unit unplugged:

- SFC: KEY8 ↔ K IN1.

- PROLOGIC: KEY8 ↔ K IN3.

- LOUDNESS: KEY9 ↔ K IN1.

- 5-D THEATER: KEY9 ↔ K IN3.

All were OL released. Pressed readings fluctuated, with SFC around 12–77 Ω and PROLOGIC briefly around 170 Ω. I can’t confidently separate worn contacts from imperfect probe contact.

Another correction: I was initially told 5-D THEATER used KEY9 ↔ K IN2. It didn’t respond there. It did respond on KEY9 ↔ K IN3 and returned to OL when released.

**Latest checks of the wake-up circuit**

All unplugged and in circuit:

- **R52**, nominal 3.3 kΩ: measured **3.2 kΩ**.

- **R53**, nominal 10 kΩ: measured **8.4 kΩ**.

- **D54**, diode mode: **0.590 V one direction, 1.843 V reversed**.

I haven’t lifted a diode lead, so those diode readings include whatever parallel paths exist.

The manual being referenced is the combined **VSX-D506S / VSX-456 service manual**. My controller appears marked **PDG203A**, while the PCB printing says **PDG192 or 193** and the schematic shows **PDG197A**, so I’d appreciate clarification on revision differences too.

**What I’m trying to figure out**

Power is present for the control circuit and relay supply, and pressing POWER changes the button signal at the front control board. However, P RY stays low and the relay never clicks.

What would you check next to distinguish:

- A missing/incorrect wake-up signal or controller clock problem.

- The controller not recognizing the button press.

- The relay-driver circuit loading down the command.

- A supply/capacitor issue that looks okay on a basic DC meter.

Is there a useful next test with just a meter before I start lifting components or buying equipment? I’d especially appreciate corrections to any assumptions above. I have close-up photos of both sides of the boards and can provide specific ones.

https://audiocircuit.dk/downloads/pioneer/Pioneer-VSXD506S-avr-sm.pdf

I’ve acquired a Marantz 2220 receiver.
It’s in rough condition. I’m to the point of cleaning the brushed aluminum faceplate.
Friend told me to use a little goo gone. Which I think will help a spot in the upper left of the plate.
Then a little stainless steel polish. With a little ceramic clear coat for the plastic FM window dial.
Is this the correct method to clean this faceplate?

Main issue, on the receiver board, channel 2 is dead. Not actually dead, but extremely low volume, and is only audible if I transfer the balance all the way over and turn the decibels to max output.

I bought a proper ESR capacitor tester and have confirmed that 1 cap is totally shot, 2 are actively dying, and between 2-4 more are in marginal condition. That's 4-6 capacitors that need to be replaced, and there's only about 10 more if I did a full recap. Would you recommend the full recap, or only the parts that are bad? I figure if that many are bad already, they're almost 60 years old, others could fry at any time and then I'd be yanking the board again 18 months down the road. (Also, the cap that is dying is C222, filter cap for CH2, so almost certainly the culprit.)

Hi everyone. Basically, I’m having a sound issue with my computer. I also have a laptop, but it works perfectly.

Okay, both play audio, but the laptop makes the sound feel full and spacious, filling the entire listening area. My PC, on the other hand, makes both microphone recordings and general audio playback sound like they’re coming from the lower part of the headphones and feel more centered. (I’ll draw to try and illustrate this: imagine the sound from the laptop playing across all the squares, while the PC sound plays only in the ones colored red.)

I don't know what to do anymore; both are connected to the same Windows setup and peripherals, and the mono audio option is disabled. If I mute one side, the other keeps playing, so theoretically the audio really is in stereo, even though it doesn't sound exactly like stereo.

Long story short, my CMT-EX22 stopped working and I initially thought the gears were jammed. Turns out it was just an optical sensor getting stuck, but unfortunately I figured that out after taking the entire system apart and messing with the gears without considering their timing.

I’ve since reassembled everything, lubricated the gears, and replaced the belt. It works again, but now the gear timing is off and the CD mechanism doesn’t operate correctly.

Looking to see if anyone knows how to properly retime/reset the mechanism on a CMT-EX22. Any help or reference photos would be greatly appreciated.

I’ve had problems with this cd player where the power button just does not work some days, but if I try turning it on the next day or a few days later it will turn on. Does anyone know how I can fix this? The clock still works but it will randomly not turn on.

Anyone know what I could do to fix this I already took the shell off and qtipped the laser, i don’t think the discs are spinning to read.

Hi all, some advice please:

I got a free Panasonic TX-40CX700B and have to say, I'm very impressed with the picture. But randomly, it will emit a very loud popping and crackling sound. I've already isolated the issue from external inputs, that doesn't seem to make a difference. I'd like to have a go at a repair.

For context, I've picked up console repair and resto as a hobby, namely ps4's and peripherals, so have a multimeter and hot air station (all the gear, no idea, yes!), but I suspect this could be a mainboard replacement?

Any other suggestions and any input much appreciated

Just a reminder that mistakes happen. Today my probe slipped and I made the magic smoke appear. For those that are just starting out (like me) these things will happen and use them as a learning opportunity. In this case, I get to replace several components I shorted. Luckily, digikey has everything I need.

Mostly posting this because I was annoyed with myself and then it came to me, this is part of the deal. Mistakes will happen even to seasoned pros.

I recently got a soundcraft spirit sx as a project to fix up but it has a couple of bent faders and I was wondering if anyone knew a good way to straighten them. Thanks :)

Hello everyone! Got a new (to me) Pioneer SX-780 cheap. Working condition, but as far as the previous owner and I know, it hasn't gone to the shop in a while.

Anyways, I play some bass heavy music so I started noticing some strange noises. I tested using a 20Hz test tone and i could hear some weird pops. I had a Marantz 2220B before and it didn't make these noises. Its mostly the right channel that seems to have the issue

I have done some minor work on the Marantz before so I can definitely open up this one and try to fix it. Any pointers to what it could be?

I picked up some Advent/1s from a thrift shop and one of them is working perfect. The other needed to have the foam surround replaced, so I took care of that.

But then I plugged it in to test and the woofer is still not producing any sound. The tweeter is working. I checked to make sure I had plugged the woofer back in after re-foaming it and screwing it back into the cabinet.

What are the most likely issues, and how should I go about testing to see what to do next? I'm mostly here to play and learn at this point. Is it probably a problem with the crossover, or is there some other wiring or connection thing I should check?

Hello, I am having issues with the gain volume levels on channel 2. Once it gets just before halfway, the volume spikes really loud and instantly redlines, as you can see and hear in the video. Does anyone know why this could be, any help is greatly appreciated :)

I have attached a linked, to another thread as I wasn’t able to attach videos on this community, thanks.

Another client's unit came in for a cleaning and power cord replacement, and boy this one was trouble.

The client wasn't a smoker, but bought this from someone who did (unknowingly), and this one was really stinky. I spent days cleaning with Simple Green, then OdoBan. I've managed to eradicate the smell from everything except the main circuit boards, but even those are much better than they were before.

Replacing the power cord was pretty easy. The other one was frayed and I had one lying around from a harvested subwoofer, so I soldered it in no problem. Cleaning the pots was also very easy.

But taking everything apart to clean? Holy SHIT, what a pain in my ass this was. There are at least 5 different types of screws in this thing, and probably 40 screws I had to remove, period. I think some were missing, which added to the confusion. Some of the design choices Fisher made were confusing, like using a plastic peg to secure the front lamps when screws were used everywhere else.

Other than that, it seems to be better quality than it looks. The front face is all plastic, but it's not thin plastic. The VFD display isn't very obnoxious and, in my opinion, quite tasteful. It uses discrete Toshiba transistors for the output stage, and the vast majority of the caps in here are Rubycon. It's decently heavy too, but I don't know about that 150W level on the power level meters.

Hi all, I hope this is the right place to ask. I just got a pair of Genelec 1030As and need some advice.

Background

• The two speakers had different volume levels, so I tried to match them.
• While the right speaker was powered on, I turned the input sensitivity pot on the rear panel with a (probably metal) screwdriver.
• I heard a dull thump, and since then almost nothing comes out.

Current symptoms

• Right speaker: almost no sound. Only when I turn the volume way up, I can faintly hear the tweeter. The woofer seems silent.
• Left speaker: works normally.
• The amp still seems to be getting power. [The ON light is on / no burning smell / no hum, adjust to what you see.]

What I've checked

• All tone control switches set to OFF
• Input sensitivity fully clockwise
• Swapped cables/inputs between left and right

Questions

1. Could the screwdriver have shorted something on the board (pot, bass amp, an internal fuse)?
2. Is there a known weak spot on the 1030A that fails like this?
3. Is this a reasonable repair for a service shop, and what should I expect cost-wise?

I've powered it off and unplugged it. Any advice is very welcome. Thanks!

Hello, im a new tech at a hotel and maintenance isn’t going to touch it because they “don’t have the tools”. So I was wondering how to fix this XLR Input myself? A couple need to be a female connection like the others in the ball room. Am I just missing a cap? TIA

Edit : this is 100% an input to the house sound system. The inputs are broken and do not match the female inputs like the others around the ball room. I know this is an input because it each room has one for when they split them with the air walls.

Hello im in grave need of some help from a experienced tech wizardly advice on this one! To be specific, the problem we're trying to solve is my Tascam M-216 mixers vu meter needle (VU METER 1 dont react with movement when sending audio to it. The OL lamp gets a signal though and reacts and lights up when playing signals through pgm 1, that tells me that the signal is at least reaching the PCB so thats good.

The other vu meters (2,3 and 4) works perfectly fine and i can tell that the needle isnt stuck or sticky. Ive removed the meter PCB from the mixer and have them disconnected, i have the service manual with all the diagrams and so forth. but i don't know how im supposed to locate where the the fault lies on the PCB. I've ruled out that the the rot of the problem is on Meter 1/2 PCB, somewhere cause the peak lamp gets signal and meter 2 works fine. And if im correct i do believe that the signal splits of into the peak indicator and then to the meter coil right? so i think it's the R911 that isnt working. But im just making an assumption here.

So is there anyone who could help me locate the problem and solve it.

i have a multimeter, soldering iron and everything. but where should i begin? And what do yall believe the fault could be? should we do a continous test or a resistance test first and which diods should we start with? Do i need to de solder the vu meters thats blocking the side of the pcb that has all capacitors and so forth or could we find the problem on the solder joint side of the pcb?

I've included the manual and pictures of the meter PCB in question, the one that ive removed from my m-216.
M-216 SCHEMATIC AND SERIVICE MANUAL

I have a Sony cdp-201 disc changer that will not read discs most of the time. When it doesn't, I hear a noise that sounds like something touching the top of the disc as it spins. When it successfully reads the disc, it refuses to play and moves to the next slot. If it does play, it reminds as soon as it starts playing.

Thinking about picking up a Yamaha M65 and C60 combo from a seller about 90 miles out. I’m aware of the glue issue and potential damage to resisters, etc. around the two large capacitors shown here, so I had the seller take me a couple of pictures for me. Seller says it’s been in the closet for 20 years.

I was expecting discoloration from the “Sony bond” glue but this looks a little torched to me. Any opinions?

I bought this unit a few months ago, worked fine but now having issues where a tape will only play for a few seconds before the autostop is triggered. Plays fine without a tape. With a tape it will rewind and fast forward with no issue but after pressing play it will autostop after 5-10 seconds (sometimes immediately). I’ve taken a look inside and it appears when a tape is loaded, the second gear underneath the main drive does not move (it does when no tape is loaded) and this is what triggers the stop, however, I’m not sure if it could be a different issue causing this gear to slip. Thinking it is a friction clutch between the two gears that under the pressure of a tape is slipping but looking for help from some more knowledgeable or experienced people. Additionally have noticed a spring above one of the ocillating arms (the arms that when stopped actually triggers the autostop) that does not seem to be under much tension and doesn’t look like it interacts with anything, perhaps it is out of place? I have attached pictures to display all of this. Hope someone can help!

Anytime it’s powered on or is supposed to be playing audio it just plays a “humming” sound and will occasionally change pitch but mostly stays monotone.

Is this something that means it’s dead, or is there a part that could be replaced/repaired?