Sony CFD-775 Restoration

[shutterguyphoto]

Started a thread about this gem in General Chat, figured I get the restoration project started here. Found this on eBay last week, had to have it, wanted one since they came out in 1990. Seller packed it well, FedEx got it to me in great shape. Overall the cosmetic condition of it is a 7 out of 10 minus the dust. 1 mark on the center piece next to the A deck door, 1 deep scratch on the left speaker, varioius finish marks. CD works about 70% of the time, takes awhile to seek from track to track, some discs show "No Disc". LCD displays light up, some segments on the cd side occasionally go missing. Decks are not working with a cassette in them. Remote included came from a CFD-560, found a slew of CFD-770 remotes on eBay, ordered one.

Now I will say I am an A/V guy, background in home theater and car audio, these boxes (770 &775 series) have always has amazing sound for what they were, competing with shelf systems. Not cheap back in day at almost $500, as a teen no way I was buying one. Not light either at 26lbs, not including the 8 D batteries needed if you wanna take it somewhere that doesn't have an AC outlet. 4 AA batteries are needed for the clock. Full logic decks, hi-bias recording, hi-speed cd dubbing, 2-way bass reflex speakers, these units were loaded. If I am correct Sony didn't make anything to replace them with and they downsized the boxes that came after before the MiniDisc era hit.

Anyways, 1st thing 1st, speakers and grills needed attention, took them apart to see what was needed. Grills must be glued in as I couldn't get them out, no problem got plenty of painters tape. Got everything unscrewed, Rustoleum Semi-Gloss Black and Clear paint from Walmart and went to work. Speakers were faded, grabbed a fat sharpie and got to coloring. Put everything back together and they look much better. One issue, the plastic cabinets vibrate from the bass when the speakers are detached, might make a small wood brace to go across the middle screwed in from both sides to stop the flexing and vibrating. More to come........

 

[Tinman]

Looking good.

Btw, if you need a parts box, there's a 770 listed on eBay for $1500, lol.
It's being described as "pristine".
The only problems are the cd and cassette players don't work.
And by the way, his feedback score is a whopping 0.

 

[shutterguyphoto]

Looking good.

Btw, if you need a parts box, there's a 770 listed on eBay for $1500, lol.
It's being described as "pristine".
The only problems are the cd and cassette players don't work.
And by the way, his feedback score is a whopping 0.

Thanks, getting a little more done daily.

Lol, I seen that. That must be the limited edition Sony ES version. I might pick up another one for spare parts, I see there is one on there for under $200.

 

[Brutus442]

I love these restoration threads. Great work!

 

[shutterguyphoto]

Moving on to the decks, pulled them apart and noticed the belt in both of them was a deteriorated and a mess of black goo. Fortunately it's only one belt for each deck, unfortunately the Sony part number is discontinued and not found anywhere. Called PRB Line at Russell Industries, they gave me an idea to use string to measure the length, came up with 9 3/4" or 247mm, ordered a belt kit with multiple sizes. Grabbed some calipers and measured a belt that was close to 123.5mm folded. Installed both of them and the decks play fine, forward and reverse, recording as well with no sound issues.

My issue...... Deck A makes a chattering noise when you Fast Forward or Fast Reverse, from what I can gather, the head block and brake do not raise to allow the spindle gears to spin freely. The brake sits on the gears and that's where the chattering noise comes from. Not sure how to fix that. I've included pictures and video below.........

 

[Tinman]

It looks like the head mechanism is going down far enough initially but then bouncing back up.
I'd look at whatever draws it down and is supposed to hold it there.
It almost seems like that mechanism is advancing too far, like it's out of sync.

 

[shutterguyphoto]

It looks like the head mechanism is going down far enough initially but then bouncing back up.
I'd look at whatever draws it down and is supposed to hold it there.
It almost seems like that mechanism is advancing too far, like it's out of sync.

Thanks, I’ve been racking my brain all through the service manual. Can’t find any troubleshooting for the issue. Play mode works fine, gotta be a gear or something that’s not locking the head mechanism and brake in place for FF and REW. Deck B works perfectly and they look identical.

 

[shutterguyphoto]

Mounted 2 large wooden dowels in each speaker cabinet to minimize rattling and flexing from bass driver.

 

[shutterguyphoto]

Moving on to the CD section, was having an issue with the unit finding tracks, you could here it searching for a 30sec or so before it would get to a next track or any track for that matter. Sometimes, the further out tracks it wouldn't even play, just search. Digging in the service manual I see there is a focus (RV703) and tracking gain (RV704) adjustment, for symptoms like I am having. With no oscilloscope on hand I am essentially flying blind here. Sony would have you unsolder and resolder bridges for adjustments with these two settings and I have ZERO clue why.

I popped in a disc, made a note of where the gain settings were and moved them ever so slightly, 2 things happened, track to track access got down to 1 to 3 seconds and the missing segments on the CD lcd are no longer missing. 4 out of 5 cd's I tried spun up immediately with the TOC, track to track worked perfectly as it should. I still wanna get my hands on a multimeter oscilloscope to look at the waveforms.

 

[hopey]

It maybe the flip flop head, the cog cracks and then slips on the shaft. Try adjusting the position on the shaft then when it works correctly you can glue it into place with primer and superglue.

 

[skylergirl]

I have my radio since 1992! My college days. Works like the day I bought it! I tried selling on marketplace, but it's not moving. It's SO HEAVY to ship Any other suggestion where I could sell? What do you think it's worth? Missing remote. No restoration needed at all.

 

[hopey]

I have my radio since 1992! My college days. Works like the day I bought it! I tried selling on marketplace, but it's not moving. It's SO HEAVY to ship Any other suggestion where I could sell? What do you think it's worth? Missing remote. No restoration needed at all.

Give it to a friend they will like you.

 

[Accordvsick]

Hi there! New member here. I just bought a cfd 750 from a thrift store. Cosmetically in great condition. Cd player works but the tape players do not. I am able to fast forward on one of them, but when I hit play it does not spin. Does that still mean there is a belt issue? Curious which belt did you purchase? I see you mentioned you bought a kit, wondering if I can purchase the one belt if you know the size. I also noticed I am missing one of the rollers on the left cassette side. Anyone know if those can be purchased?

 

[shutterguyphoto]

Hi there! New member here. I just bought a cfd 750 from a thrift store. Cosmetically in great condition. Cd player works but the tape players do not. I am able to fast forward on one of them, but when I hit play it does not spin. Does that still mean there is a belt issue? Curious which belt did you purchase? I see you mentioned you bought a kit, wondering if I can purchase the one belt if you know the size. I also noticed I am missing one of the rollers on the left cassette side. Anyone know if those can be purchased? View attachment 57637

Hey sent you a PM, haven't touched my box in forever. I measured the distance of the belt with a string and ordered close to that a kit from Amazon.

Amazon.com

Not sure where to get the roller parts.