Servicing a 1971 Sansui 2000x stereo receiver. Repair of "no fm stereo"

nice looking receiver that got new caps and transistors in the signal path, but no fm stereo despite the lamp being on.
let's see why

[@dell177]

Great video. I've worked on a lot of equipment from that era and always thought the Sansui gear was better made than most, well laid out and easy to work on, kenwood was another company whose gear was better made than most. I bought the 2000 when I was serving in Korea in 1969. We were on a remote mountaintop microwave site and we repaired the microwave systems to keep communications up and working. My receiver lost one channel during a thunderstorm so i took it apart and did some troubleshooting. i found one fuse and output transistor blown, this was still in warranty but I had no easy way to get it down the mountain and up to Seoul where the repair depot was. I wrote Sansui in Japan and explained how the unit failed and told them I wanted to buy a set of transistors and a schematic and would send them a check as soon as i knew the amount to send. A little over a week later I got a box in the mail with the parts and a service manual. They sent a note with a technicians phone number in japan I could call if I needed any help, they said the parts were supplied under warranty so no payment was required. i replaced the bad transistor and it's driver and the unit worked fine. I wrote back to Sansui and thanked them for their help and told everyone I knew what a great company they were to work with.

[@robinsattahip2376]

That is service.

[@jwl9286]

Wow! That's a great story to add to this video. Another happy ending! Oh yes! Thanks for your service!

[@southernfriedawesomeness9464]

Vlllllllllllllllllllllllllll

[@projectartichoke]

My brother in law bought an outrageous Sansui quadraphonic receiver during Vietnam and the thing still works perfectly and sounds great, really cool playing old quad vinyl and tapes.

[@JordanPier]

My folks have a QRX-6500 that is an absolute tank. Only have to clean the pots and switches every 10 years or so.

[@steveoszman8746]

Have a similar sansui at the tech with pretty much the same issues. So glad I have a shop with services at your level in the area. Ya got the skills!

[@tectalabyss]

Hi JP. Cool piece of History. Glad to see it working 100% again. All my best.

[@randyr.parker2698]

What a beautiful piece! Glad the owner has taken such good care of it over the years. Suspect those ornery little transistors will continue to cause problems in the future though. ;)

[@waltschannel7465]

Yes, they are germanium, they will cause problems.

[@hartengel7724]

Nice to see you back JP. Great video!

[@williamwong5627]

When I was young, the Sansui Eight Deluxe caught my eyes. But I could not afford it only dream about it. Time flew. Love watching all those vintage stereo brought back to its glory days.

[@clockinthe916]

Good job Sir. That is a beautiful Sansui.

[@2flyabove]

Thank you for this educational video. I'm impressed with your knowledge in electronics. That Sansui looks fantastic. Cheers.

[@Shadowban69]

I have a 4000 among numerous other vintage amps and it is by far my favorite looking and sounding amplifier. I use it everyday for hours on end. Once again, I learned a lot from watching how you diagnosed and rectified the fault. Looking forward to more videos. 👏👍👊

[@craigm.9070]

Thanks for your time breaking down your troubleshooting and repair of this gem. Not very many in this condition out in the wild anymore. The owner is likely very happy his receiver is reconditioned for its next phase of life, that phono stage should sound sweet.

[@waltschannel7465]

Excellent fast progression to find the bad part. GREAT description of the quick and dirty alignment!!

[@cjay2]

That is one beautiful receiver - I love that wood cabinet and the green illumination.

[@jdmccorful]

Good work , easy to follow. Thanks for your time and demonstration.

[@lox_5017]

Thanks Jordan for another great video...keep them coming.

[@blitzroehre1807]

Those Sansuis were truly well put together. I am currently working on a predecessor, the type 250 with tubes. Bit of a rats nest without the PCBs but chugging along replacing caps and a few wayward resistors. Amazingly the tubes all test good..

[@robertplayer846]

Thanks for the tip on the crossover distortion. I've been rebuilding a few of those notorious 1040 boards; a couple with new drivers. Will def scrutinize the wave forms now.

[@jeffreyhickman3871]

These are from the good 😌 old days. I understand that the capacitors need changed by now, but these were a GREAT 👍 radio. My dad had something like 👍 this, back in 1976, or 1977. It was on a shelf in the living room of our mobile home 🏠. Lum and Abner was one ☝️ program we used to listen 👂 to. The baseball ⚾️ game sounded so great 😄 on it. So did the news 🗞, and music 🎼. Although the stereo was solid state, it did a good 😌 job. It had the same green lighted dial. I’m pretty 😍 sure it also had an 8-track, and record player. Although cassette tapes were around then (and the late 1960’s), a cassette player wasn’t featured on this stereo. Please keep these GREAT 😊 stereo videos coming!! Your friend, Jeff.

[@scrappy7571]

So nice to see a well cared for Sansui. They sure don't make 'em like that anymore.

[@rexmeanor2561]

Thanks for the Video. Enjoy watching them every time. My brother brought a Sansui 2000 back from Vietnam in 1969. It’s been in storage for years. My brother says he knows where but not likely. Hope you can fix it when the time comes. Your neighbor, Rex

[@JordanPier]

Happy to service it for you. Bring it on down when you get the chance.

[@whstark]

Great repair , repaired allot of audio in 55 years , all manufactures inc video etc. Old car radios fun and consoles also all the tape deck's , reel to reels tascam etc. Srarted with tube stuff first then all the way to modern yamaha, harman, JVC etc. commercial and consumer. Retired now Just working on Teensy, arm, risk 5, PI, Pi pico some with wifi and Audio synth Ic's fun for me. Keep up the great repairs, reminders for me esp tuning IF's etc. I used sencore sweep generator also a heathkit in past. Favor-et cap checker the Sencor model LC73 z meter.

[@Justplast]

Sansui Are Beautiful A1 job Jordan

[@richpayton7162]

I had a 2000 that used miniature screw-thread lamps that had corroded to their sockets, an absolute PIA to get them out. The AM tuner performance on that particular Sansui was phenomenal. I could do impressive DXing at night, from inside a room with a chicken wire & stucco exterior wall using just the fold-out AM antenna.

[@Android_Warrior]

Hi Jordan!, Thanks for fixing my cassette deck, still going strong!

[@JordanPier]

You're welcome. Glad you're enjoying it

[@Android_Warrior]

@@JordanPier : What have you done with the 2 test equipment that I gave you?

[@JordanPier]

@@Android_Warrior still working on finding enough time to restore them both. I want to do a video on each. Just need the time.

[@Android_Warrior]

@@JordanPier : Looking forward for the videos!

[@peterbuntinx881]

Hi Mister Jordan Pier, Thank you very much for your hint. I have now a good practical conceptual schematic of a stereo radio/tuner. With regards Peter

[@wayneg296]

👍👍😎✌️🤟Wish I still had mine. With a guy like you to take care of it.

[@MrElectrowhiz]

I have and use a 2000x receiver. Most everything is fine on it but it has noise, which is most likely all the 458s in there, broken balance control, and all the panel lights out. I have a box that has all the parts for the receiver. I am going to refurb the receiver as a project in the next few months. According to the serial number, my receiver was made in late 1969. Thank for the fantastic video.

[@jbetnar]

Can you explain how you dated it with the serial number? I have one that I am wanting to date.

[@larsmichael3383]

Beauty! Using a saw tooth signal makes it easier to reveal cross over distortion and clipping. I did not see any 8 ohm load resistor when you did the power test.. but I trust it was there. I always adjust DC with regards to zero signal. Basically I want no DC in normal working mode, and I really don't care about uneven clipping at max output because it will never operate there with speakers connected.

[@tcpnetworks]

These were glorious receivers in the day.

[@michaelwright1602]

Still are, I have the 2000 model and am blown away every time I turn it on. My Zu Omen Dirty Weekend speakers sound incredible with this tuner.

[@philam1973]

My brother had the same model, probably same PX bought while in Vietnam while stationed there. Sadly lost in a divorce in 1990.

[@jameshopkins7333]

Boy if you ever want an apprentice, I'm there.

[@zx8401ztv]

Well done :-D It looks in really good condition, well worth the effort. Ooow those bead transistors, shango would be spitting at them lol.

[@randomthings6351]

I have a 5000 x bought it in 1971 in Korea I love it

[@JordanPier]

Yours probably escaped have the F-1040-1 boards in the amplifier. More likely has the F-6013 boards. Much more stable.

[@zulumax1]

Sansui's have a lot of silk screen errors on their boards, many electrolytic capacitors will have the + printed on the wrong side on the board. I tried the across the rail fuse method for setting the bias on my Sansui AU-7700, however I powered it down and forgot about the inrush current to charge the capacitors, blew the cheap $7 Harbor Freight meter. Oooops! Got those because I like monitoring both channels, and they are cheap in case something like this happens. There is a second way in the service manual with requires unsoldering the red wire to the output board and hooking the meter there, that way the inrush current bypasses the meter.

[@boggy7665]

Ha! When I was 13, I took a wad of paper money saved from my paper route, and bought a Zenith Allegro shelf unit w/ LP, AM/FM stereo. Had this exact problem. Took it back to the store & got another.

[@adamtparker6515]

May clean my dad's up as a bday present. Family still uses as an amp even though all switches except AUX is kaput. Should also add 'as seen on Season 1 of the hit 20th Century Fox program Vega$ starring Bob Urich😊' Good for gen info as I 'get the call' for all Mom and Dad tech issues...

[@larryshaver3568]

shango worked on an Astro sonic and there were a bunch of open capacitors on the stereo fm board

[@wendellporter4875]

i am starting to see more and more of those type of transistors go bad might just be with age they start to go same with those dual pnp 2sa798's

[@markhull9156]

Great explanation and description! I have a 197x G-2000 which exhibits the symptom on only one FM station, 89.1. All other FM stations come in fine.Is that the same issue or something different? (I can get the same station on a different band.) Thanks for your help. I appreciate it.

[@augustwestusa]

The hard part for me is just trying to figure out how to open it up. Mine is a 3300. Looks like there are only 4 screws in the back, and some of the knobs in front look like they have tiny screws. I don't want to do anything other than clean it and some of the push on off buttons wont stay depressed. Trying to find a video that will help me. Not sure if I should even attempt it!

[@zulumax1]

I had a 2000A model, not sure what the difference is with the 2000X. Single push pull outputs generally sound warmer and more involving in my experience. A for American perhaps since this one was probably overseas model is my guess. Multi voltage capable most likely.

[@sauces_official]

the X suffix on this line of sansui amp usually means it supports two phono inputs

[@Seiskid]

Interesting IF alignment. Obviously it works. I'm curious - real question - why this is better than feeding it a 10.7 sweep and adjusting the s-curve. I would have thought peaking runs the risk of ending up with the IF being too narrow. Interested in why you did it this way since it clearly worked well.

[@JordanPier]

Its not necessarily a better way, just faster, and the average listener will not notice the difference. In a laboratory environment with a distortion analyzer I'm sure using a sweep/marker generator and following the service manual would yield more precise output and lower THD. The If amplifiers are only designed to do one thing, and that's amplify the 10.7mhz while rejecting as much side-band junk as possible . I'm peaking those after making sure the RF output from the tuner is the best. Then I can assume that if all stages are working, peaking the 10.7 signal will allow for the greatest amount of information for the FM detector, which is the crucial element in demodulating the music. The way these tuner circuits are designed, adjusting the primary for null and secondary for best symmetrical clipping with poor signal shows that I'm about as close to on center of the detector as I can be. If I were not able to achieve good output then I would break out a sweep and look at the curve on a scope. Likely something in the detector circuit would be amiss assuming amplitude of the 10.7mhz was sufficient.

[@jwl9286]

Another very interesting note to this project! Thanks to you guys I think I am understanding it more and more.

[@joepowers3731]

Awesome video. I have a Sansui 2000x stereo receiver no power going to lights. I knew there were a few bulbs not working so I opened It up and blew it out. I plugged it in it was on aux . When I turned it to FM I saw a spark come from the wire going to the light bulb all the way to the left of the display the wire was exposed and grounded , then all the lights went out. stereo works great just no lights at all. Any ideas.

[@JordanPier]

You probably blew the fuse for the lamp supply. Follow it back to the transformer. Dual lamps are not lit on those unless the radio is selected. Otherwise you should see a light of what In put you're on (aux, phono, etc)

[@joepowers3731]

THANK YOU!!!!!!!!!@@JordanPier

[@hotpuppy1]

I've got a 1964ish Voice of Music solid state console that I rescued from the curb. Has phono and reel to reel. Got phono working and tape seems to work (no tape to actually try it but microphones feed out OK. Problem I have is neither AM or FM work. Amp output is OK. No stereo light, nothing. Dead quiet. I have the schematic. Tried checking some voltages with multimeter at points shown on diagram. Voltages are off in several places on the IF board. Suggestions as to where to look first? I don't have signal tracer or working scope. Don't want to fire the parts cannon. I assume that it has some dead electrolytics. Nothing physically obvious (no leaky, burned parts.

[@JordanPier]

Since both am and fm are dead start at the power supply line that feeds the tuner. Voltages can be a little off, but usually more than 20% low and stuff stops working.

[@XGarage-nj2uf]

I have a 2000x with a hum in it. Tore it apart and have yet to fix it. On my list though.

[@Shadowban69]

filter caps

[@peterbuntinx6140]

HI, very good video. You are using a good conceptual schematic. Is it possible to dowload? Thanks Peter

[@JordanPier]

You can get a copy of the service manual from hifiengine.com

[@tonefordaze4808]

Hi Jordan… I was wondering if you could help me out. I would like to use speaker channels A + B simultaneously with this setup: One pair of passive speakers to be wired in parallel to a powered subwoofer in Channel A. A second set of passive speakers connected to Channel B. My question is: will I blow my Sansui 2000x because of ohm impedance? I hope you’re able to help. I’ve been scouring the internet for information but it’s not easy to find an answer. Thank you

[@JordanPier]

So long as both sets of passive speakers are 8 ohms or greater it should be fine. The amplifier input of the powered subwoofers are very high impedence - usually around 47k ohm

[@JordanPier]

It's also true that if it's a 2000x, it should have a preamp out/main-in loop on the back. Using a y adapter you should be able to feed preamp level info right to the powered sub and run your passive speakers directly from the sansui without having to parallel them with subwoofer inputs.

[@tonefordaze4808]

@@JordanPier The powered sub is a Paradigm PDR8. Not much info out there as I tried to find out what it’s impedance was. But if it’s standard for subs to have that high impedance, that’s good. Thank you.

[@kennynvake4hve584]

I see a Sansui 5000x for sale at an auction site, not ebay, and its at 500$ now.

[@chyde99]

A Newbie question. Where do you inject a signal on these vintage receivers in order to troubleshoot with an oscilloscope? Thanks, I really enjoy your videos.

[@JordanPier]

I typically go right into any line level input. Aux, tape monitor, etc.

[@chyde99]

@@JordanPier thanks so much!

[@chyde99]

@@JordanPier may I ask what signal or audio generator do you use? Thanks

[@JordanPier]

@@chyde99 really old Leader audio signal generator. Don't remember the model, but there are plenty of new ones out there that do the job

[@chyde99]

@@JordanPier thanks!

[@larryshaver3568]

my guess would be the multiplex amplifying transistor may be shorted

[@sabbath7081]

I have a 5,000 a that my father bought when he was over in Vietnam and it was at my grandmother's house for years after she passed I took it speakers as well and one output fuse keeps blowing on the right channel I think it has something to do with the separate output boards one board has some sort of a short in it haven't been able to find it looked at the diagram and I'm kind of new at getting into the electronic stuff heavier I'd love to figure out what's wrong with it but if I keep watching videos like this eventually I might figure it out.

[@JordanPier]

If yours has the 1040 amplifier boards inside, its likely a failure of the black square bias diodes sitting atop the driver transistors. This is common. They open, and blow the output stage. There are ways to fix it, but not for the beginner. Eventually I'll do a video on how to repair them. Its worth the effort.

[@sabbath7081]

@@JordanPier Cool, I did do a basic short test on things I put one lead on a chassis and was touching around places and it seemed to be something of that sort on one of the output boards, like you say a little box on top of a transistor. It doesn't look like it would be an easy fix because the board is attached by a ground strap and some other stuff, I did see kits on eBay for rebuilding those boards same number board is what was on the wiring diagram inside the unit. I can tell it's never been worked on before.

[@nomusicrc]

We're those giant capacitors the size of soup cans at the end of the video

[@SuperAsianDude1]

I have an issue where every input works great on both speakers but if i put it onto FM Auto on my 4000 only the right speaker has sound and the left barely any. what could be the issue?

[@JordanPier]

If you press the mono button and the channels combine you've either got a failure of the output of the multiplex module that's at the right front of the machine, or on the phono preamp that serves as a preamp for the mpx output.. Either open capacitor or failed buffer output transistor. You really need a signal tracer or scope to find it. Xraytonyb has a good video on how to build a budget signal tracer. Either c428 or 429 on the mpx board is open (depending on channel), c601 or 602 on phono board is open, or one or more phono amp transistors have failed. See if both channels operate when playing a turntable through phono. If not, you've narrowed down what board the problem is on ; )

[@SuperAsianDude1]

awesome, thanks for the detailed info. I really appreciate it!@@JordanPier

[@zukispur5493]

I run a sui AU 717. PROPER

[@JordanPier]

Probably one of the best integrated amps sansui made. Some shortcomings with brown glue and fuseable resistors, but excellent none the less.

[@Turboy65]

Do yourself a huge favor and buy yourself a really good soldering station. I recommend a Hakko FX-951.

[@JordanPier]

Yep. Need to save some bucks. The fx-888 has worked for me for now. The old 930 finally had a base station failure after 15 years of daily use.

[@joearnold6881]

Idk. It’s been 2020 since like 2016 still.

[@jbetnar]

How do you get it out of the case?

[@JordanPier]

4 screws on the sides and 4 hex screws on the bottom

[@jbetnar]

Thanks. I forgot about the bottom hex screws. I had a 4000 model before in just the black metal case. My 2000X is working well other than FM is weaker than it should be and Stereo light is not working. ​@@JordanPier

[@jbetnar]

I just sat down with my 2000X and my FM tuner is actually working fairly well. It will play in stereo, but my lamp may be burned out. All of my dial bulbs were bad. I have a kit coming from ebay. I did notice my Muting Off button does nothing. It mutes on or off. ​Another thing is my meter will not go above about 3.5, even on a 50,000W signal 2 miles away. Is there an adjustment for just the meter? @@JordanPier

[@JordanPier]

@@jbetnar don't remember if there is a meter adjustment. However the meter and muting circuit are intertwined. The fact you're muting and the meter shows a low signal may be related. the fact the tuner muted with muting "off" also points to that circuit

[@jbetnar]

Thanks for the information!​@@JordanPier

[@Gpray75]

@jordanpier Hi there, xraytonyb sent me your way...i have a Sansui au717 that ive been looking to get restored/refurbished and was hoping you could help me out!? 🙏

[@JordanPier]

Sure. Inbox me. Vintageavrepair at gmail dot com

[@Gpray75]

@@JordanPier Thanks, Email sent 🙏

[@26Jorgeb]

Hello Sir, I have a Sansui 5000A with the same problem.I get signals from fm stations but no sound comes out.Could you be kind and generous enough to tell me what you think about the problem ?Thanks. Enrique Jorge Enrique Jirge

[@JordanPier]

Check the last IF Integrated circuit just before the detector. If it has failed it will yield this symptom. Use a signal tracer or scope to confirm. 3rd IF yields signal meter information, 4th fires into the detector for output. I assume you can get sound on AM/MW?

[@garfo992e]

I have this model with the same issue, would like to have repaired, wondering if you are interested and are close to me, I’m located near Pittsburgh Pa.

[@JordanPier]

Nope I'm on the opposite side of the states in California

[@user-fs8gg5ki2y]

I'm trying to fix a 6060 Wich has no sound and I'm about to put it in the trash,no one wants to fix this devices anymore

[@JordanPier]

Not too tricky to figure out. 1. check for DC voltage at the amplifier output at the relay. Should be 24v for the coil and that's it. 2. If that's good, check power supplies against the schematic. Usually there is + and - 35-40 volts, 12v and +30v for the preamp. If in doubt, consult the schematic. 3. if that's good, then protection circuit itself has issues. Definitely advanced troubleshooting needed. If you want to throw some money at it, send it to me. Inbox me on how. vintageavrepair (at) gmail dot com