Sony ST JX520A Am Stereo FM Stereo tuner repair
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- Опубликовано: 29 авг 2024
- There are 3 faults on this unit. Dead memory battery, burnt out display light, and it won't receive AM Stereo. Lets fix it.
This is a very rare tuner these days, and it is a really hot receiver, pulls in really weak stations.
Those motherfuckers at youtube have again flagged this video as unsuitable for advertisers. Patience is wearing extremely thin.
Brilliant. Repairing a water damaged/rusting Sony STR-VX2L (dreaded 100Hz hum)...recapped now and replaced STK463 (which presented with blown surface mount [edit: resistors] under microscopy despite transistors apparently being ok)...moving now to replace three failed diodes surrounding the regulator.. (none of which in my parts bin so awaiting parts) and after all this, a possible transistor failure lurks in the background. 12voltvids would probably have fixed it in a few minutes :) Find these videos really useful. Technique excellent. Also had to get a 100R fusible resistor (having an additional white band marking) which had not come across before
That was a really cool video, especially the stereo-decoder part. Good work there and the new LEDs really look great and perfectly match this elegant receiver. Gosh, there is something to these late 70s/80s circuit boards, they loved their jumpers but the design just looks great and from what I've seen, seems extremely robust. Thank you very much for sharing this!
Wonderful fix. I miss fixing electronics the way it was done in the old days. Nowadays changing modules is all that's done even here in Africa.
Hello dear friend
I like watching your successful repair work
The sony stv502 FM stereo light is not lit
Stereo light works with R25 resistor finger contact connected to IC21 integration on mainboard. All polarity capacitors in the circuit have changed, but no solution has been found. Only the R25 is working in stereo with the finger contact to the area where the resistor is.
The device is nice, for now mono only works.
Big thumbs up for the pronunciation of Roof and Solder :D
Wat a kool Sony st jx 520a am. FM you owen
Sony actually had a wide variety of AM Stereo equipped tuners and receivers in the 1980s, but many were quite rare, and all of their home tuners and receivers were blocked from being sold in the USA due a lawsuit by Motorola claiming that Sony's automatic multi-system decoder chip violated their patents. (The portable radios with manual switching between AM Stereo modes were unaffected by the lawsuit and were sold in the USA, thus are much more common.) But I know the JX-220A AM Stereo/FM Stereo tuner was also sold in Canada, because I have one and that's where it came from.
And they wonder why AM stereo failed!
I just grabbed a ST JX520, without the "A" on the end. Do you know the differences? Thanks for posting this video, it might help me later, interesting regardless.
Someone in a forum mentioned that the model without the A doesn't have AM stereo. Also that the A stands for the Australian model.
@@recepteuravendre9660 Alright thanks. Audiokarma forum?
@@scolopede It's from a comment by dan_tech on this page www.stereonet.com/forums/topic/248850-suggestions-for-a-great-am-tuner/
Some other site about AM stereo says the A models were only sold in Australia and Canada.
Is there any link for replacement battery ? Is it 2025 battery or 2032 ? Can i just unplug battery and replace it ? Or have to replace holder module ( tab ) as well ( as you did in the video ) ? Thank you!
Would you recommend recapping one of these receivers, or just leaving the caps alone?
Sony parts prices were outrageous in the 70's.
perfect from the bottom to the top, from the start til the end
I've had FM receivers in the past with a similar issue that didn't want to lock in to stereo but unfortunately I never had a schematic but by slightly turning a cpl pots I got them working again. I think overtime the pilot settings go out of their set spots
Which pre and power amp did you use? I have an E80ES/N80ES powering Yamaha NS-1000Ms, love it.
I did have the TA-E1000ESD and a pair of N55ES power amps for a while, but I much prefer the E/N80.
I had a TA N 77 ES and TA E80. Should have kept it but a friend wanted it real bad, and offered me a good chunk of change for it, so I cut it loose, and started buying expensive cameras. That is basically what it boiled down to. I wanted a professional camera for my video biz, so I unloaded a bunch of gear I had that I thought was overkill.
This video shows why AM stereo is a farce and why it didn't last. It can't overcome AM's susceptibility to noise and interference.
FM broadcasting didn't start in Australia until the late 1970s (many TV stations had to move out of the FM band first).Even then, only NEW stations could broadcast on the FM band. Existing AM stations were stuck on the AM band. So listeners had to stay with AM if they wanted to listen to their favorite radio stations. AM stereo was merely a compromise.
Fortunately that is no longer the case. With digital radio now gaining popularity, I guess FM will follow AM to the ranks of historical interest only.
Hello david, im one of your fans out there, been watching your videos everyday. Thanks for sharing your knowledge. I just have a few questions, i have sony fh313 and my problem with this guys is the fm volume is too low but the other functions works just fine. And is there any way that i can use phono in as line in?. Thank you so kindly.
The phono input can't be used for line level for 2 reasons. One is the signal level. Now, you could pad the level down to a phono level, but the second is the RIAA equalizer curve.
Vinyl records were NOT great sound carriers. Despite claims that they sound better, the only reason they sound as good as they do is through pre, and post equalization. The bass and treble is rolled off when the master is cut, and then expanded by the phono preamp.
So even if you were to attenuate your signal so as not to overload the preamp, it would still sound like crap. You can use tape monitor inputs as additional line inputs, or make a switch box to add additional inputs.
The FM problem, I have no idea off the top of my head.
I appreciate you took time to respond. Thank you so much!
Really instructive video. I just bought this tuner and mine needs repair too but I can't find the service manual anywhere. Any chance you could scan or photograph yours and post it somewhere? Thanks.
When you said you have owned it for years I was thinking bad caps. Loads of old Bakelite radios from 50, 60s have old paper capacitors and always fail over time. Replace the capacitors and alive again. Same with guitar amps, dead channels, no power. Easy fix.
This was definitely not an easy fix.. Part f the reason was, well it is AM stereo. Not something that you see every day. I bet the majority of the viewers have never heard of AM stereo yet alone seen a tuner, and the majority of techs never got the opportunity to work on one. This is the first one I have worked on, and I had to build the C-QUAM encoder to be able to test it!
I wasn't referring to your fix was easy. Generally, old radios that have dead power supplies and old paper capacitors is an easy fix.
Brian Percival
Yes I know. Tube sets change all the caps and you are good to go.
I own Old School Sony Mobile ES car audio equipment. Some of the very best.
AM Stereo was Rare in Australia, i picked up a Teac CR 900 hifi unit with C-Quam Decoder, i need to buy a transmitter kit, but they are pretty expensive here
The kits are expensive here too.
I have a sansui rz3000 no signal in fm stereo but mono have a signal.what the wrong bad ic or bad cap?thanks
Have you ever worked on Sony car cd player tuners? I have a Sony cdx-m650 with a bad tuner module. Having a hard time finding information or parts to fix.
No never worked on car audio.
Any ideas on we’re I could find information or parts?
No sorry, never worked on car audio shop at work that refused car audio. Stems back to the days when he did car audio and would charge people $100 to remove and another $100 to replace the equipment in the car on top of the repair charge of course nobody wanted to pay the remove / install charge so they would bring equipment in it would be repaired and then they would somehow manage to blow it up reinstalling it by connecting the power wrong and then come back demanding a refund so the boss made the decision that no car audio would be repaired and that was before my time at the shop. I welcome his decision I wish he had the same attitude with portable audio like walkman's ghetto blasters phones fax machines etc. When I had a helper he did all that small crap but when he retired that was on me and I absolutely hated working on that crap. needless to say a couple years later I was done working on all that crap and I left the business swearing to never do it again. managed to stay away about 10 years and then people kept coming to see me after the shop closed because there was nobody left and people started showing up at my door begging and pleading me to work on stuff so I kind of came out of retirement to work from home and that's what I do now and then I started the RUclips channel so I started doing more of it just as content for the RUclips channel basically.
I appreciate it. This video you have is the closest I can find to what I need for information. Nobody cares about these stereos anymore. But I’m determined to fix it. I’ve already told it apart and put it back together with no avail. Knowing how you test the capacitors and ic”s. Is the knowledge I don’t know how to find the problem. Thanks for your input..
Great videos! I just bought a Technics Sa-202 Receiver, noticed the left channel had no sound. Took the cover off to inspect and noticed the power amplifiers were not soldered to the board. Could this be the problem to why the left channel is not working? Thanks kindly, the amateur audio player.
Well that depends. It is possible that the part is bad and someone disconnected it to prove the fault. If it was working and the solder just cracked then yes that could be your problem.
The leds just made that display perfect, nice coverage and colour.
Pll's can be a shit if they don't get the correct input or feedback levels, i am talking about communication equipment but a pll is a pll.
So did you retune the pll system after the cap replacements and acheave the correct voltages?
I have never heard of AM Stereo before. I don't think we ever had it in the U.K.
We had it here from the mid 80s through to mid 2000s. There are still a few stations operating with dedicated engineers keeping them on the air, but as equipment fails they are going back to mono or just going off the air. Lately there has been a mass exodus from the am band.
@@12voltvids To be honest, I haven't listened to radio from FM/Am etc. for over a year now. I am afraid it is only off the phone or the computer. FM radio here is appalling at best and AM is an even bigger joke. Never had a DAB set so I can't tell how that is. Maybe it is ok, but do not know. Thank you for the reply and entertaining videos. I used to do video recorders and TV repairs back in the 80's and 90's but gave it up as it was cheaper to buy new than to repair. Though, I must admit I do not miss it. The "public" can be very unforgiving if the repair you do only last about 2 years!
Are there any clear channel stations I could probably receive at night broadcasting in AM stereo. There is a station in my area that once did broadcast AM stereo. I doubt they do now unless they have a host airing on one channel in the caller in the other LOL.
There are still a few stations in stereo. I have picked up a few at night from time to time. It is fun when you find them for sure. Just llike it is fun to find a pirate radio station.
Nice tuner, i should do that led mod with my Teac Tuner
Good Video!
AM stereo must be mostly a Canadian thing. We have a number of HD radio stations here in Phoenix but I've never heard of any AM stereo stations or ever seen a radio that can receive it.
AM Stereo was available everywhere, but the FCC dropped the ball and approved 4 incompatible formats. Back in the 80's it was popular, but today the stations still transmitting are few and far between. For those with an AM Stereo radio the thrill is when the skip is rolling and a distant station comes on. I have an old radio out of an 86 toyota that has AM stereo, and I pick up the odd station in the evening but other than that there is very little to listen to today. Had the FCC settled on a single format back in the early 80s then AM stereo probably would have survived, but they allowed free market, and once they did pick a single format all the radio stations that were broadcasting in one of the loosing formats simply turned off the stereo and went back to mono operation.
Many factory car radios in the 80's had AM stereo. My wife used to have a mid 80's Buick and it had AM stereo. My mother had a Totota and it had AM stereo. It should have succeeded in the market, but due to poor decisions by the FCC it was doomed from the start. In a car environment AM stereo was perfect. No picketfencing, of fading that is common with FM, and the range of most AM stations was superior to FM stations.
Your cat is amazing.
And you tell a crooked tale! Just kidding. Definitely not, but couldn't resist. that. Forgive me.
BTW cats are cool too and it would be nice to see this one. Even more so because of its tail. Love the way you tell people what each component does, not just what it is. Thanks
Agreed. Those Leds do a great job.
I'm too young to have know this VCR head clogging pandemic in the early days. What put an end to these bad counterfeit tapes? SImply VHS coming down in price?
Even when the price of name brand tape came down, the knock offs were still there.
When licensed VHS tapes were selling for 5.99, you could get 3 knock off tapes for 5.99.
People started getting wise though, when they were paying 30.00 a pop to get their machine cleaned and have to do that every week or 2. They smartened up and stopped buying the no name tape.
@@12voltvids I guess I got lucky then... Bought lots of tapes without knowing about these issues or worrying about buying good ones. That or the stores stopped carrying these garbage brands where I was doing my shopping
Is your cat Siamese? After generations of inbreeding, most Siamese cats have a kinked or crooked tail at the tip.
No she is a tabby. I have 4 cats, 1 siamese, 1 Ragdol, and 2 tabby.
The one with the croked tail came from a black cat with a kinked tail. The other tabby came from a Ragdol. That one thinks he is a siamese, as he squawks like one. Some siamese have flaws that they are trying to bread out. One is crossed eyes. I once had a siamese with crossed eyes, but the one we have now is as perfect a sample as you will find. She is from champion bloodline.
Siamese sure are loud. I had to baby sit a Siamese kitten for one nigh for an Arab family I drove for. I'm soft with all animals, but this kitten was a nightmare.
It sounded like it was possessed by the devil, non stop squawking and vicious with it. I didn't get a wink of sleep. The poor thing had probably been mistreated but It put me off the breed. Some of them have a surplus of character. Definitely a flaw with this one. Its a shame.
taketimeout2
I have had at least 1 Siamese continually since I was about 10. They are very smart. The one I have now which is my daughters cat is toilet trained and she can even flush when she is done as we put a chain on the handle. We have to keep doors locked as she knows how to open doors with lever handles on them too.
Awesome.Animals are smart. I think that kitten was called Damien I remember a Raven sitting on my windowsill and a Black Doberman outside my front door. Probably just a coincidence! Lol.
AM stereo ???
Yes, AM stereo was and still is (for a few stations only) a thing
that's a great class!!!
And you say owt for out.
No that's how the southerners say it.
i am surprised,how much of electronic inside...
we never had stereo on AM here in Europe
AM Stereo not used anymore was a fluke in the 1980's.
mains powered led lights emit alot of rf noise
These are not mains powered. They are powered by the regulated 12 supply.
Might not be able to watch it all today because of bad weather but will try and watch the rest of the video tomorrow, If you have an old fluorescent lantern then it might be possible to use the tube from it, I am sorry but I am trying to watch enough of this video before hurricane Ophelia comes and the adverts get in the way and I want to get my system shut down before the power goes off, I had a radio that had stereo on LW,MW,SW as well as FM and DAB and also the radio used DRM (Digital Radio Mondale) which used a Texas Instruments Blackfin DSP processor but the selector knob got broken off so is impossible to select other stations, if you are wondering what radio it was it was the Morphy Richards 27024, something interesting here
www.google.sr/patents/US5222144
Re: the hum. There are a few things to try.
Try putting a .1mf cap across the antenna input to ground.
Recheck the .1mf caps across the power supply are still good or add more.
The main antenna receiver chip may also need a .1mf cap across its power supply.
If that does not work then a component within the circuit is causing the noise then
use this circuit from Mr. Carlson's lab to trace it down.
ruclips.net/video/uVkJqqZroN0/видео.html
This should clean up that hum.
MidnightVisions
The hum is only on the weak signal from my transmitter in the other room. Once I moved closer the him went away.
Yes the hum is being generated in the receiver circuitry somewhere. The receiving circuitry is raising the noise floor to pick up the weak radio signal. The hum is being generated by a bad component, and its rf noise is above the noise floor of the receiver. This is why the receiver picks up the hum on weak signals, but not stronger signals.
A receiver circuit can never have too many noise bypass caps. When Sony designed the circuit, the parts were new and capable of absorbing the noise. Now that all the electrolytic caps are time expired, more noise is being generated than the original bypass caps can handle. The noise will most likely increase over time unless the bad part is found.
So explain why then, every radio I test on the bench, receiving the signal from my test transmitter has the same hum. I can bring my walkman into the workshop and it sounds the same, and it only does it on this signal. There is much noise generating stuff here, from monitors, hell even the digital camera I record with generates a ton of noise.
whats the time mark in the video where this happened?
MidnightVisions
Where what happened. The noise from monitor or scope?
My dad pronounces 'solder' like 'sawder'. I pronounce it the way the British do. That's pretty rotten of Sony to charge so much. I have been in customer service for 13 years, and while sales is basically a sort of exploitation, it isn't right to overcharge.
The first shop I worked at when I was an apprentice the owner pronounced it "sorder". You probably guessed he was Chinese.
His last name Ng but pronounced ing.
@@12voltvids If his last name was 'Ng' he was probably a Vietnamese.
You must of VE7OR from sony
in the south part of america we pronounce roof the same as you those yankees are weird
generate thumbs down? hahaha,not from me ,lol, nice tuner
it is "SOL-der"...( /ˈsɒldə(r)/ )it always was, it always will be ! Some American dictionaries give that horrid (but wrong) pronunciation in phonetics as an alternative. This is incorrect,when in doubt consult the OD ! It even gives sound files on how to pronunciation the word in the proper way
I have no idea where the Americans got the idea to change to pronunciation on one of Her Majesty's Words, but that is neither here nor there.
An American told me, that this was the way he pronounced it for 66 years...well...he'd be wrong for 66 years.
Their 'Simplified (and incorrect) English'' can be rather infuriating at times and is testament to grammatical anaemia.
One shudders at the pronunciation of words such as 'cement' in certain parts (səˈment) . The way this is mangled in some parts is beyond description!
Paddy,
ruffled
FIRST!
12voltvids hahaha👍👍👍
I smell a rat Send in the cat Lol.
John sweda
It's a joke. I just happened to be on line when it finished rendering .
John sweda
No not at all. Just to test old radios. There is a kit being sent to my by a kit supplier to build and banggood is sending me a little more power full unit to evaluate as well as a ham radio. Like the one I currently have that is one of those lighter players for the car they are very low power but fm can be interesting especially with an external antenna.
Good vid