Another 5000A repair

[CATSCATSCATS]

Hello all!

first post, and long time lurker.

I've had this little gem in storage for a couple years, and recently i have been upgrading my Hi-Fi setup, and i believe this receiver will be just the ticket.

Thrift store find: 20$

I have not tested the sound of the unit, to check the channels. I have only turned the power on, to check the lights, which seem to function properly (in hindsight i feel i should not have touched the power button, but at the time I did not know of the recall for the F1040 boards, and i still had not purchased the sansui, so if it was DOA then i would have left it at the store.), and I didn't let out any magic smoke, nor does the unit smell like or look like anything caught on fire.

I popped the cover off the top and had a look inside: see attached pics.
i think the S/N means it is from march 1970

I have some decent technical skills, and i can solder a bit. I don't have an issue with trying to repair the unit myself, but i have no test equipment (aside from a rudimentary multi-meter).

Id like to use the "skippy124 " mod to the bias transistors and bias diodes, but i am stuck,

The thread is old and photobucket is dumb and locked the pictures,
but mouser looks like they have all the components i need.

are the components a direct 1 for 1 swap?
can someone direct me on the manner in which they are installed? (including polarity of parts if necessary)
i can probably translate a schematic, but i am not electrically inclined, i'm more of a mechanical thinker.
Photos speak a 1000 words, i can replicate the fix visually, so photo would be ideal.

any help and advice i would really appreciate

thanks!
Scott

 

[tom3]

Those boards don't look that bad, no burned fuses, and they have the somewhat better drivers being the -1 series boards. I'd check the two rear panel fuses first off, if not blown the amps might be ok. If blown there is no doubt a problem. Usually one blows, the owner swaps them and blows the other one too. This is a picture I saved from the mod that was shown on here, only picture I have though.

 

[The Fuxtor]

If you use Chrome browser or Firefox, they both have a photobucket extension that will fix the blocked photos! I've used both and haven't had any issues!

 

[Tom B]

I use Chrome, and still only see Photobucket site that want you to sign up for a service billed annually

 

[The Fuxtor]

I use Chrome, and still only see Photobucket site that want you to sign up for a service billed annually

If you look in the settings under "Chrome extensions" or something similar, you can search up a photobucket fix....
This only works on computers.... My phone app version doesn't seem to have extensions? But as a work around the Firefox app does have photobucket fixes that work on my tablet/phone...

 

[CATSCATSCATS]

I'd check the two rear panel fuses first off, if not blown the amps might be ok. This is a picture I saved from the mod that was shown on here
View attachment 1082256

Thanks for the photo tom, that should get me started. I'll edit my firefox extensions to try to get the photos working.

 

[CATSCATSCATS]

i got the photos from skippy124's thread to work with the firefox extension, thanks for the tip!

before i start any work on this unit, i wanted to let you guys know that all the fuses look new, and are not burnt out.

However, the right channel fuse is missing. this is a cause for concern because id assume somthing bad happened to pop this sucker, and if it was removed to source a replacement, then i may have to dig into the reciever a little more.

if im looking from the front of the assembly, and the 1040 boards on on the back right side, which board is responsible for the right channel?


If the issue was only with the recalled parts, would this blow the right fuse? would modifying the f-1040-1 boards be the fix i need? (skippy124 had same issue with right channel being blown)

does anyone have any tips for removing the 1040 boards for surgery?

i appreciate all the info, thanks again,

 

[tom3]

The boards are reversed channel wise. Just trace the wire colors from the (labelled) fuses to the boards, orange and red. I use a standard night light for a dim bulb tester for the power to these boards, hooked across the fuse terminals. When power is supplied will light up orange and then dim some if all is good. If it stays bright orange, short somewhere Try it on the good channel first to see how it works. I usually just cut the braided ground straps rather than try to de-solder them, remove the screws, lean the boards over to get good access to the other wires. Removing some of these components is tough, leads are bent over and soldered heavy. Two soldering irons works good, one with a small flat tip used to straighten the lead after the other iron melts the solder. Then hit it with the sucker.