Sansui 9090DB Restore Part 1 Repair
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- เผยแพร่เมื่อ 10 มี.ค. 2023
- This receiver would not come out of protection. It was sent for a complete refresh/rebuild. Before doing that, ALWAYS repair the trouble first. This video shows the steps taken to diagnose and repair the issue causing the unit to stay in protect mode.
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"Always repair before rebuild" - Words to live by, these 9090DB's seem to be getting scarce out in the wild; those that own them have either spent the money to restore them or they are run until failure. Thank you for your time on this one.
Thankfully I started living by those words from the pitfalls encountered by others. I can assure you, that's not my usual M.O. 😁
Not sure why it took YT so long to recommend you, but better late than never. Glad to be aboard Ray.
Nick, I just checked out your channel and can honestly say that from the one video I saw you pack more useful information per minute than any other channel. And while I never had your channel recommended either I'm now subscribed.
Oh, and welcome aboard!
I scooped on up a week ago at auction. Glad I hung on. Only has two blems/issues really. Light behind about AM 1000 is out. And there are two very minute chips in the veneer that you don't notice unless you look right at them
I bought deoxit D5, F5, and G100 and following your lead on removing the tuner section, gained access to as many pots and switches as possible. There WAS obvious signs cleaning was needed and afterwards it sounds like a brand new unit. Looked around at caps and only saw a couple that were barely showing signs of bulging/doming. Truly blown away by the insanely high quality sound this receiver puts out. Currently running a pair of Monitor Silver 9i's and all I can say is wow! Now I'm torn between keeping it and selling it. This one's right up there in the $4300 class I guarantee it! Between the beauty of the entire front panel and the sound this amazing beast puts out, it's hard NOT to love it. I'll probably come across the information at some point but I'd sure like to replace that bulb that's out and while I'm at it all it's comrades too.
For all things lamps Dave is the man:
dgwojo.com
Good to see you back!
This may be the first time anyone has said that to me! 😁
Glad you’re back. You made us take a sabbatical from your channel. Another great repair!
Thanks Bill! Have to step back every once in a while or I'll fall down the rabbit hole and never come out. Anyway, more to come soon as the refurb progresses!
The thing that is killing off DB9090's is "Dolby disease". I'm hoping you will address in this series.
My 8080db has never had an issue. Knock on wood. That being said, if the DB function ever pooped out I'd sell it asap. I NEED it.
Another great video Ray. Keep them coming.
Thanks Ian. Not only will there be more on this receiver as the restoration proceeds, but a buddy just dropped off an integrated amp and a tube preamp he couldn't get sorted out. The fun never stops here!
I restored mine 2 yrs ago, including pining the dreaded dolby board. Installed LED's, but eventually removed them and went back to incandescent. Just didn't look right, esp the power meters. Last summer I built a ToliTom F-2624 board, and that improved the sound & reliability.
Scrappy, very cool that you did yours. The owner specified incandescent lamps, so that's what's going in.
Please shoot me an email; my address can be found under the ABOUT heading. I've got a few questions about the ToliTom board if you don't mind.
Nice repair job ! It's always nice to get the right schematic, if it exists !
Isn't that the truth! Got lucky with that for this unit.
Great repair video. Thanks
Thanks Uri. More to come on this beast as I go through the restoration!
Nice. I just had one in for a basic cleaning / service, and just the other day got another one in with “status unknown” lol- thanks for posting this!
"Status unknown"... that's what my shrink said. 😝
J/K. Let us know what you find in that one, Mike!
Another great video. Keep up the good work.
Please don't call it work. It makes it sound like... work! 😁
Thanks for the comment, it's appreciated!
It’s nice to see you back! I agree with you about repairing it first. Those trimmers seems to be a bit weak for that purpose indeed, very nice repair.
Thanks. Got some Bourne trimpots ordered. 1/4 IIRC.
1/4 watt. 😁
If you’re in the close by DC Maryland area, I don’t mind personally driving it to your shop. Sincerely, Stan.
Hi Stan
I don't have a shop, I'm just a hobbyist, albeit a pretty serious one. I have a full time job and other responsibilities that severely limits how much work I take in. I'm currently working through a backlog of things that friends have left with me.
FTR I'm located in South Florida.
Where R U located? I also own a AU 20000 integrated Amplifier that needs attention with my 9090 DB. Please let me know as soon as possible. 😊
Hi Ray, thank you for your efford posting this , i got mine sansui 9090db db not working and after a lot of work , Mine still stays in protection mod with F2624 board pluged in , when I pulled borad out everything works fine, now I'm thinking of that new board that you mantiond from TONY , did you have chance to test it out? Thanks
Find Fuses F01 and F02. See if you have DC voltage on one or both with it in protection mode. IF YOU DO THIS WORK YOU DO SO AT YOUR OWN RISK.
@@raygianelli3612No DC on both fuses ! but my question is about that new F-2624 board from Anatoli :)
@@nick3200 I have no information about a new board.
Ler me add this, the early versions of the F-2624 used a Vbe circuit for the idle current (BIAS) with a 1K trimmer, later versions (and tolitoms) boards use those Sanken STV3H diodes, with a 100Ω trimmer, probably the previous tech didn't know that and he went with the schematic.
No, the board had 100Ω trimmers, but the one measured over 760Ω. That's what threw it into protection.
@@raygianelli3612 Got it!
Hello There! Thanks for the video and all the info that goes with it. I just acquired an 9090DB w/o the Driver board and the protection light is doing fast blinking red. Would bad power transistors will cause that? Thanks again
Ando, check for DC voltage at F01 and F02, black lead to chassis. If you have DC, you probably have shorted outputs.
REMEMBER, IF YOU DO THIS WORK YOU DO SO AT YOUR OWN RISK.
@@raygianelli3612 Thank you it turns out I have 3 bad left channel Power transistors. Another question- my right bias stays at 10 Ma regardless of the VR04 settings. Both DC offsets at 0.10 mv When I m playing music the speakers seems to be balanced though sound and power wise- Is this something I need to be worried about? Thanks again
@@user-mq8ne1fs2r It's indicative of a problem. How are you taking the measurement?
@@raygianelli3612 following the Manual bias instruction removing fuse and using Fluke meters- running the amp 5 minutes - the Left channel is at 30 mA - It is the Driver board issue?
@@user-mq8ne1fs2r Problem is most likely there. TR09 or TR10 (depending on which channel you're working on). Should have +1.2 volts at the collector and -1.2 volts at the emitter, and should change with the bias control. Be careful not to slip with a probe! Minigrabbers are good here.
I need a volume pot for my 9090 can you help me?
Afraid not. eBay is where I try to find things like that.