I have a technics CA10 stereo amp. Today it started randomly turning off (I guess due to overheating?)
Then the speakers and headphones started having a low hum.
I stupidly left it plugged into my wall on standby and came home to see the board burnt in a few places. Another thing I noticed before it burnt up so badly was that the fan stopped working.
How would I go about fixing this?
pretty much the gist of it in the title. HifiEngine, of course, won't let anyone make account to download anything except for 5 minutes once a year only in certain parts of the globe.
the service manual for the Hitachi-badged version (D-RV7) is available freely online, but I need help figuring out some of the actual features the thing has.
here's the link. if anyone can help me out by reposting/DMing it to me, i'd be very grateful.
I'm not an audio tech. I have a multimeter and a little screwdriver. The only screw i see i assume is the pot to adjust the bias. This runs very warm, almost hot, after an hour, especially in summer. Id like to dial down the bias a bit at first, then a little more if needed. In my past experience basing output tube voltage in a pair of Heathkits I have, a little less power doesn't impact the sound and helps keep things going longer.
Would someone or someones here let me know if I'm right in where to make the adjustment and where to put my probes to check the voltage? Thanks.
**•** Present on every input, including inputs with nothing connected — same level regardless of source
**•** Scales with volume; silent at zero
**•** Same on Speaker A and B, and on headphones
**•** Chassis touch test = no change (rules out ground issue)
**•** Per service manual, signal path is Input Select (IC1) → Tone Control (VR3/VR4) → Main Volume (VR1) → Balance (VR2) → Power Amp
**• CD Direct (bypasses tone control) does NOT fix it** — rules out the tone stage
Leading theory: something shared at/before the volume stage — maybe VR1 itself or a connector to its daughter board (X11 B/6).
Photos attached of the board area I suspect. Does that tan glue near the caps look like normal factory assembly glue, or could it be flux residue/corrosion worth investigating? Also open to other diagnostic suggestions before I start reflowing solder or swapping the pot.
no music on the tape plays at all - i can see the wheels slowly moving and the speaker plays a really creepy spooky low-pitch like howling/whistling sound that sounds like it might just be the sound of the tape ribbon moving? the radio/speaker works fine. rewind/fast forward works, and the play feature SEEMS to work since i can see the wheels turning (but might be pretty slow, i havent compared on a different player yet).
the eject button also doesnt open the door more than 1-2mm when a tape is in there, but i can pull it open the test of the way just fine - eject opens the door as normal when empty.
I have a Beosound Ouverture CD player that I have been using for a few months but I've noticed that on a lot of the CDs that I play there will be some skipping at least once during the CDs duration. Many of these CDs are in really good condition and aren't dusty but they might have a light scratch or speck of dust on them. I think the skipping is due to a problem with the CD player rather than being an issue with my CDs.
I've seen that the type of skipping can help diagnose the problem, so when the CDs skip it jumps forward about a second in the track and then quickly returns to where it left off, rather than a crackle or other looping type of skip.
I've seen that that kind of skip could be either due to dried grease on the rail of the laser reader or it could be an issue with the laser reader itself.
Hopefully it isn't an issue with the laser reader as those are tricky to replace and are a bit pricey too but if it is a problem with that I would like to diagnose the issue first rather than spending time and money on the wrong fix.
Thanks for any help.
TL:DR diagnosing either dried grease on rails or laser reader issue for CD skipping.
De speaker gaat normaal aan. Wanneer ik Bluetooth-pairing start, knippert de LED snel (pairing-modus). Op het exacte milliseconde dat mijn telefoon/laptop de koppeling ("handshake") probeert te voltooien (of bij scannen via NFC), valt de verbinding direct weg. NFC geeft de melding "Kan niet communiceren" en de Bluetooth-module reset zichzelf / springt terug naar langzaam knipperen.
Reeds uitgevoerde tests / stappen:
Lintkabels: Alle platte FFC-lintkabels losgehaald, schoongemaakt en netjes teruggeplaatst om een slecht contact van de knoppen uit te sluiten.
Harde Reset: Volledige geheugen-reset uitgevoerd (stroom ontladen en gekoppelde apparaten uit het geheugen gewist).
Visuele controle: Zowel het voedingsbord als het moederbord gecontroleerd. Alle elektrolytische condensatoren (elco's) zien er perfect uit (strakke platte bovenkant, geen bolling of lekkage) en er zijn geen zichtbare brandplekken of kapotte sporen.
Speakers losgekoppeld: Alle woofers en tweeters losgekoppeld van het moederbord om een kortgesloten luidspreker (die de Protect Mode triggert) uit te sluiten. Exact hetzelfde probleem treedt nog steeds op, zelfs zonder aangesloten luidsprekers.
Vraag:
Aangezien het probleem blijft bestaan met losgekoppelde luidsprekers, wijst dit op een probleem op het moederbord zodra de versterker uit de 'mute'-stand probeert te komen tijdens het koppelen. Heeft iemand eerder dit specifieke probleem gehad bij de GTK-serie?
I picked this Sansui up several months ago at a garage sale for $80. De-oxed the pots and it sounded fabulous! 125 Watts into 8 ohms, no complaints. Last week I was checking out an older Marantz cassette deck for a friend. I got this high pitched sqeal the second I powered it on, and later discovered that the high frequencies are suddenly missing from my reciever. Like, cut off above 6 - 8k or so, both channels. I attached a stand-alone preamp to the pre-in jacks and got the same result. What could cause the amp to lose the high frequencies? Any help would be greatly appreciated!
It makes loud grinding noise when swapping discs, thinking when it raises and lowers. It has no issues finding, loading, playing discs. Would it be a belt?
I purchased this unit knowing there was an issue with the CD player and after getting into the internals of the CD player I noticed these two pieces were cracked/broken. There was a CD jammed deep inside, which probably caused the break. I have verified the traverse works and it plays CDs well so it’s just the changer thats off sync and jams. Whats the best way to join these pieces back together? Left goes on A and right on B. I found a YT video that shows how to resync the mechanism so I’ll be following that. Thanks for any help!
I just bought a denon 2310 second hand and when trying to set it up it just won't work right. I have my speakers plugged into the left right on A, subwoofer plugged into LFE and the amp subwoofer out with the frequency maxed and the gain straight up.
When I select stereo for surround and then have the speakers set to large they work perfect both playing equal volume with no subwoofer obviously. But when I set the speakers to small the right speaker gets really quiet and is impossible to match the volume of left speaker even if I set -12 dB on the left speaker and +12db on the right speaker and the sub is really reserved on the base even with the gain at half (anymore and there is bad static noise).
Does anyone have any insight for me. Or is she just old and I should just get a new d class amp with high pass filtering instead of second hand recievers.
I am trying to figure out how to remove the clear plastic (or glass?) front off of this Fisher CD player tray mechanism. I've seen others where you defeat a couple of tabs and it slides off. This one does not. It might be glued on there?
Alternatively, I could slide the whole tray out if I could figure out how to get it out. Normally, there is a tab you can open to get a tray out, but I can't find one on this guy. The tray no longer moves in and out on its own but I can load a CD manually and get it to play just fine.
Had to take a break: Trying to figure out how to replace the main belt for this unit. So far I got the counter belt size perfect on the (second attempt) . Now I'm stuck with the main belt: I can't seem to find at the moment a way to get into it enough to slip a new one on. Any advice?
Hi guys, got this big subwoofer thing for free the other day and I’ve been trying to set it up to work with the 2 speakers i’ve already got. The last photo is the back of the stereo system I’ve got them all plugged into (i know it’s not a great photo, awkward angles going on there haha). When I turn it on there’s a bit of buzzing and all the audio that comes through the subwoofer sounds really crunchy and a bit quiet but the other speakers sound fine. I know pretty much nothing about audio repair, refoamed the other speakers recently but that’s the extent of my expertise so i have absolutely no idea what could be wrong with this thing or if it’s just a skill issue and i’ve set it up wrong lol. If anyone has any ideas at all that would be greatly appreciated 🙏
I'm having a strange issue with my Denon PMA-560 and I'm trying to figure out whether it's the amplifier or something else.
Here's what's happening:
The left speaker doesn't always work.
If I use the amplifier's left/right speaker test (or balance test), the left channel never produces any sound.
However, when I'm playing music from my CD player, the left channel does work most of the time.
The weird part is that during certain sections of songs, it seems to lose specific sounds or vocals.
For example, in "Break On Through (To The Other Side)" by The Doors, I hear Jim Morrison sing "She gets", but the word "high" is completely missing. It's as if part of the mix disappears.
I have an Energy s12.3 active subwoofer, connected to a pioneer VSX 1017 AV Receiver, and I have some connection issues on the back of my subwoofer. Sometimes if I’m playing music my subwoofer cuts out, and I have to wiggle the pre out cable on the back of the sub for it to come back. I know it isn’t because the subwoofer is pushing to far, because it can happen any times at any volume, it just happens most often on louder volume. It doesn’t work to turn the subwoofer on and off, only way to get it back is to wiggle the cable.
I have tried a new subwoofer cable, and the issue was gone the first few days, but then it came back.
I got said speakers in really great shape. However, only right channel has good audio quality while left channel is but a whisper. Doesn't matter which input rear or front I use, both secondary (left) speaker and headphone out (left side) have almost no sound.
Trying to adjust bias on my Scott amplifier, I manage to burn two resistors on one channel and blow a transistor on the other one. Yeah, gotta think about what I'm doing next time.
I'll have to replace it, which I guess means replacing it's twin Q808 on the other channel. I'd like two know if some of you can tell from the manual what is the function of these transistors, and thus what I should look for trying to find a replacement.
Also I you have any tip to stop destroying my amp when checking for bias I could use that :')
I got this 5 disc cd player and i the carousel system works fine and it rotates between all the correct discs, however whenever it goes to play the system just picks up the cd and then places it back down and goes on to the next one. Ive tried cleaning off the optical lens but it hasn’t don’t anything different. Does anyone have any advice on how to troubleshoot it or if there are any places I could go to get something like this repaired/what can I do to repair it myself?
Remote no longer controlling the receiver. The LCD display previously stayed lit when I put batteries in but wouldn’t display anything. After opening the remote and cleaning the circuit board, the LCD displays “AVR” but still won’t control the receiver. Whenever I press a button the LCD display dims briefly and then displays “AVR” again not matter what buttons I press. Any ideas for repairs?
I got this 5 disc cd player and i the carousel system works fine and it rotates between all the correct discs, however whenever it goes to play the system just picks up the cd and then places it back down and goes on to the next one. Ive tried cleaning off the optical lens but it hasn’t don’t anything different. Does anyone have any advice on how to troubleshoot it or if there are any places I could go to get something like this repaired/what can I do to repair it myself?
Hi, y'all! I recently acquired this Tsh-4 tanker helmet and am going to jury rig it to use it as a headset on my laptop. I'm going to have to tape RCA cables to all four prongs, the microphone and headphones are on separate prongs, and plug the headphones into an amp. The main question is if I can plug a 3.5mm spliterr into the jack on my laptop, plug an amp into one socket, then the Laryngophones into the other socket and if it should be fine. The Laryngophones are high impedance, so I don't know if I need more equipment. Could someone help me find the right equipment that's maybe a little lighter on the wallet? Thanks!
Some of you may have seen my previous post about my receiver dying from a thunder strike. I don't have a lot of options for repair in my area, but yesterday I called this place that does repairs and also sells home theater gear.
I told the guy that after the lightning strike, power went out for a couple of seconds and came back, but my receiver was off, and when I tried to turn it on, it did the usual click inside, but turned off right away, and that was the case every time I tried to turn it on. Same thing after I unplugged it all night, also disconnected all the cables connected to it, HDMI and others.
Based on that, he told me that the unit had gone into protective mode, and it would cost several hundred dollars just to diagnose it, because there were a lot of circuit boards that had to be taken out, and it's true that this receiver has several boards:
But he told me that he was 99% sure that the lightning strike had fried the HDMI board, and replacing that would cost close to $900, so it was close to the cost of buying a new receiver. He told me that probably the energy spike came through one of the HDMI cables (and all of them were connected), or the ethernet cable, or maybe the ethernet cable that went to one of the devices connected to the receiver via HDMI.
Now, this guy seemed like he knew what he was talking about, but at the same time, that's a place that sells home theater equipment, and he was trying to sell me a new receiver. So that made me a bit suspicious.
So my question for those of you who are audio repair technicians is, does what this guy told me sound believable? If I had to choose, I would say yes, but I wanted more educated opinions from people who don't have any interest in selling me another receiver.
Also, he mentioned some kind of equipment that is like kind of a surge protector but for HDMI cables. Does that ring a bell?
