Is it savable?

[Lets Go Back]

I recently pulled this Sansui 9090 Db from a old out building and was scheduled to be discarded. As you can see it was very dirty and littered with leaves and other debris. I got it on the work table cleaned the heavy stuff and vacuumed the inner components as much as possible for now. Then powered the unit on and at first I thought I had another great working receiver to add to the collection all lights functioned signal and output meters work, but upon further inspection I began to find what looks like trouble. There is no sound, protection light doesn`t do anything, and found signs of some kind of bad repair. Just need your opinion on were to start on the repair process anything will help, Thank You.
I will add more photos this afternoon.

 

[Hyperion]

It looks pretty complete, so there's your first hurdle overcome. The missing track (pic3) is nasty, with a really shoddy so called 'repair', the black wires (pic4) are worse, with a very poor joining job (!) also I can see signs that they were trapped (and squashed) between some chassis metalwork by the looks of it.

First, get yourself a service manual, then fix those issues, have a look around for any blown fuses (use your meter to check, don't do it 'by eye' alone), but check them all, and replace with the correct rating fuses. Then you should build yourself a Dim Bulb Tester (or DBT) (Google it) to use for first power-on and until you are satified there are no serious shorts or any other problem that may cause additional damage before you find the issue itself.

There are numerous threads about the 9090DB here on AK, with tons of information (do a search), but you'll find nearly all in the Exclusively Sansui forum.

Good luck.

And BTW: Welcome to AK! - and the wonderful World of Vintage Audio.

 

[NAD80]

Hello Lets Go Back, Welcome to AK. Found the Service Manual and schematic here.https://www.hifiengine.com/manual_library/sansui/9090db.shtml. Just register and download for free. Check out the Exclusively Sansui forum for threads on the 9090DB. What Hyperion said is right, Fix the wiring, Damaged track can be fixed or bypassed. Take plenty of before and after pics, just to back yourself up with parts and wiring. Good luck with the 9090DB. Keep us up to date with repair/ refurb. Too nice to not get working again. Have a 3900Z to work on. Gotta build a DBT for safety of you and the 9090DB.

 

[elnaldo]

Welcome to AK!

Before touching inside, make sure THE MAIN CAPACITORS ARE DISCHARGED (NO VOLTAGE OR JUST A FEW VOLTS ACROSS THE TERMINALS )

After that, in an unknown unit, I always check for a short circuit from emitter to collector at the output transistors. It's a common fail a shorted output transistor.

 

[Robisme]

Does the protection light start red but then go out? Do you hear a relay click a few seconds after power up?

Common for the resistor for the green light to blow.

Rob

 

[avionic]

This jumper wire needs to be tidied up. Its to close to adjacent solder connections and a potential short circuit.

 

[waggs098]

This jumper wire needs to be tidied up. Its to close to adjacent solder connections and a potential short circuit.

Yep I agree. Looks to me like that jumper is soldered to the loose traces and needs to be resoldered to proper solder points on the board

 

[avionic]

Looks to me that jumper is soldered to the loose traces and needs to be resoldered to proper solder points on the board

That and about 3" shorter..

 

[Lets Go Back]

It looks pretty complete, so there's your first hurdle overcome. The missing track (pic3) is nasty, with a really shoddy so called 'repair', the black wires (pic4) are worse, with a very poor joining job (!) also I can see signs that they were trapped (and squashed) between some chassis metalwork by the looks of it.

First, get yourself a service manual, then fix those issues, have a look around for any blown fuses (use your meter to check, don't do it 'by eye' alone), but check them all, and replace with the correct rating fuses. Then you should build yourself a Dim Bulb Tester (or DBT) (Google it) to use for first power-on and until you are satified there are no serious shorts or any other problem that may cause additional damage before you find the issue itself.

There are numerous threads about the 9090DB here on AK, with tons of information (do a search), but you'll find nearly all in the Exclusively Sansui forum.

Good luck.

And BTW: Welcome to AK! - and the wonderful World of Vintage Audio.

Hyperion, Thanks for the welcome and your response I didn`t get any time to test and check fuses, I am in 10/7 mode with work as of late. DBT and service manual in the works.

 

[Lets Go Back]

Hello Lets Go Back, Welcome to AK. Found the Service Manual and schematic here.https://www.hifiengine.com/manual_library/sansui/9090db.shtml. Just register and download for free. Check out the Exclusively Sansui forum for threads on the 9090DB. What Hyperion said is right, Fix the wiring, Damaged track can be fixed or bypassed. Take plenty of before and after pics, just to back yourself up with parts and wiring. Good luck with the 9090DB. Keep us up to date with repair/ refurb. Too nice to not get working again. Have a 3900Z to work on. Gotta build a DBT for safety of you and the 9090DB.

NAD80 thank you for the reply and your input. I was very worried about the pulled track and lousy repair attempts. Hopefully after work today I can get to the unit and have a better look.

 

[Lets Go Back]

Welcome to AK!

Before touching inside, make sure THE MAIN CAPACITORS ARE DISCHARGED (NO VOLTAGE OR JUST A FEW VOLTS ACROSS THE TERMINALS )

After that, in an unknown unit, I always check for a short circuit from emitter to collector at the output transistors. It's a common fail a shorted output transistor.

elnaldo, Thanks for heads up and the tip. Can`t wait to get started on the restore.

 

[Lets Go Back]

Does the protection light start red but then go out? Do you hear a relay click a few seconds after power up?

Common for the resistor for the green light to blow.

Rob

No protection light at all, as for the relay click I believe that I did hear it when I fired it up the first time but when I powered it on the second time to test for sound I don`t think I heard that click. I am planning on doing a little work on it this evening and will pay more attention.

 

[Lets Go Back]

This jumper wire needs to be tidied up. Its to close to adjacent solder connections and a potential short circuit.

avionic thanks for the reply, when I seen this area I thought the unit was going to be a display piece, but it sounds like after the replies from everyone I might be able to save her.

 

[savatage1973]

Back to the OPs original question--Is It Saveable?. Simple answer is YES--pretty much anything is salvageable, but the real question is--Is It Worth It?. I know lots of people in the audio, automotive and firearms hobbies that have gone through countless hours of time and thousands of dollars--same goes for antique furniture restoration.

 

[Lets Go Back]

Yep I agree. Looks to me like that jumper is soldered to the loose traces and needs to be resoldered to proper solder points on the board

waggs098, Thanks for the reply once I clean this area up I think I will feel much better about the project.

 

[Lets Go Back]

Back to the OPs original question--Is It Saveable?. Simple answer is YES--pretty much anything is salvageable, but the real question is--Is It Worth It?. I know lots of people in the audio, automotive and firearms hobbies that have gone through countless hours of time and thousands of dollars--same goes for antique furniture restoration.

Good question and one that I ask myself all the time. Is it worth my time and cost to bring it back to life because I like it and want to hear it play again or do I sell it as is and move on to something else. In this case I will choose my first option because I don`t have anything into it and with winter approaching I will be have the time for the repairs. But wait I have been saying that to myself for the last 20 years and still waiting for the free time.

 

[savatage1973]

But wait I have been saying that to myself for the last 20 years and still waiting for the free time.

LOL--I think we all have "projects" like that, and never seem to find the time. I literally have "projects" that I started years ago--maybe someday? I have buddy that built a new home over 20 years ago--I am a contractor, so I helped him out. The house was completed and is beautiful and his wife is happy (one hurdle covered)--but then we built a stand-alone garage dedicated to the restoration of his classic vintage Corvette--I think we will both be dead or in a nursing home before that thing ever hits the road LOL.

 

[waggs098]

No protection light at all, as for the relay click I believe that I did hear it when I fired it up the first time but when I powered it on the second time to test for sound I don`t think I heard that click. I am planning on doing a little work on it this evening and will pay more attention.

One thing on that series of receivers is, they have fusible resistors that go bad in them. I had an 8080 that was in about as bad of shape as your 9090 when I got it. Had to replace the fuse resistors in the protection circuit because it would not come out of protection (but the protect lights worked). About 4 months later fuse resistors went bad in the power amp section. I suggest you replace all the fuse resistors in the unit. If you can't find the proper values of fuse resistors you can use metal film resistors in their place.

 

[zebulon1]

You can remove the Amp driver card completely and power up. See if it comes out of protection.

 

[Lets Go Back]

Well I was thinking about starting on the 9090 this weekend and was gathering a list of items that I would have to get from storage, While checking the connecting points of the cut black wire I came across this on the protector circuit board. Any ideas on how to repair this new nightmare.?