Sony FH7 - thoughts and belts

So i had a chance to grab a Sony FH7 a while back from Northerner, he was so reasonable price wise and i had bought from him before so jumped at the chance. It arrived last night, i fired it up and had a listen, wow good sound, solid bass and lots of clarity, that was just on radio with no stereo lock (or at least no light), line in sounds even better, so far , so impressive.

Whilst the box was cheap the reconstructive surgery on the hernia and slipped disks lifting it won't be, jeez this thing weighs a ton. Now i don't usually do 3 piece but i had to see what these were all about, but, if i'm going to have one it had to have a working tape deck.

I cracked it open last night but peered inside and thought "nah i'll leave that", well with a day off today and nothing else to do i jumped in. I could find no guide for this so I have pieced together a rudimentary guide in case anyone else searches for this.

I'll start by saying the rebelt isn't too bad but care is needed as there are some incredibly thin wires on the side of the deck controlling its complicated mech. Also, a set of dentists tools or other thin device with a hook is helpful. The actual re-belting is like surgery!

I only decided to take some pics halfway through so bear with me.

Easy bits first, side off, rear cover off, exposing the inside. I then unscrewed the two screws holding the main board in place, with care this can be moved to one side a little. This is seen on arrow 1.

Pop the deck open and look at the sides to see the door clips, slide the door up to remove, set aside. Undo screws underneath deck to remove front face being careful to unscrew the tape selctor led board, set to one side. (Its out of sight but you can see its ribbon cable in arrow 4. Unscrew black panel inside tape deck to expose underneath, its held on by one small black screw.



I then removed the two screws holding the board on the back of the motor area, arrow 5. This is just to allow access to the screw holding down the flywheel cover so you can slip the belt over.

Its not shown but you can then remove the top plate over the top of the deck held on by 3 screws.

The board holding the play/fwd/rew keys can be taken off by the two screws, tape counter the same. Tape counter can be moved to one side and play/rew/fwd board draped off to the side. Arrows 2 and 3.

Next remove the screws as shown in red circles, the lower two indicate screws underneath.


The deck should now move freely. If it does not I may have missed an odd screw so double check. Gently flip the board over and look for the board on the rear of the motor.


Bottom left corner of this board (as looking at it from rear of deck) you will see a screw holding on the flywheel plate, this can be loosened or removed to slip new flat belt over. Once done you can gently flip the deck over and fish down through with your dentist tool to pull it up through. I cleaned all the deck and relubed while down this end to, plus changed the small belt that end.

Once flipped over looking down though the deck from the motor end you will be able to fish up the flat belt and attach to motor spindle plus attach the other belt from motor to fwd/rew pulley. Just push the small fwd/rew belt over the visible pully and fish it up to the motor the same as you did for the flat belt.

The arrow below shows the approx screw location to loosen flywheel cover and the direction to turn the deck to fish it through.



Relocate the lead for tape select LED down the side of the deck and sit deck in usual place to tackle to counter belt. There is a belt here that is important as without it play is pressed but it shuts down immediately, it turns a kind of windmill through a sensor. This operates the auto stop i believe.

Here is the fan/sensor


Attach a new belt from right hand tape spindle to fan assembly, if you have it give the sensor a blast with compressed air, this removed a lot of dust for me. I then reattached play/rew/fwd controls and tape counter and ran a new belt from windmill/fan spindle to counter.

Tested all was well and reassembled. It's a beautiful deck and made even my shitty test tape sound great. I cleaned all rollers, head, demagnetized etc once i was happy with it. I happen to have exactly the right belt so minimal adjustments were needed but they are all documented in the service manual which i recommend getting from Analog Alley. The motor has a proper adjustment point as well as adjusters for the various cams, motor speed, head raise height etc. Dont mess with any of it without the manual.





I just need to re cloth the front of the speakers now, i'll pick up some thin silver tights material and she'll look new.

I hope this helps people in the future and i wasn't too long winded.

Now if only I had an FH7 I could use this guide

That's an excellent job matey! As you say, not too difficult & pretty much common sense when dismantling the cassette deck

The sensor on the counter is a hall effect sensor, it uses light to determine that the 'windmill' is rotating & keeps the motor & heads in the play/rec position & indeed is the autostop mechanism primarily

Although perhaps a little overrated, I like these Sony's & I usually detest auto reverse decks (would still never use one for recording) but for playback these are good machines with detailed audio across the whole range & as stable as autoreverse can be!! Very nice logic controlled deck - like so many brands, this was the tail end of quality from Sony before the dreaded 'market quality' decks came along
My lovely looking CFS-5L uses the crappy deck - & build quality is the opposite of your lovely Sony here, it's dire - at least it looks nice lol

Nickeccles said:

That's an excellent job matey! As you say, not too difficult & pretty much common sense when dismantling the cassette deck

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Ha thanks Nick, to be honest if it reads like "not too difficult" i didn't mean it that way, it was very tricky i just thought it would of been less tricky if i had a guide to follow so i did a rough one!

After lugging around Freddie's FH-7, I can attest to the hernia part. Nice work!

Fatdog said:

After lugging around Freddie's FH-7, I can attest to the hernia part. Nice work!

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Me too lol as I had to package this bugger up and lug it to the courier place

I'm gonna pop it on the scales later, i just can't believe how heavy it is!

T-STER said:

I'm gonna pop it on the scales later, i just can't believe how heavy it is!

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I think it was about 11kg?

Northerner said:

I think it was about 11kg?

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Service manual has it at 15.1kg. Dayum!


I just realized that we have some FH-7 service manuals here:

https://boomboxery.com/forum/index.php/files/category/4-sony/

One is just FH-7. The other is FH-7 MKIII. They might help in the future.

Must be less than 15kg as that's more than the courier will take lol

Thanks for the manuals Fd, very handy

T-STER said:

Thanks for the manuals Fd, very handy

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Thanks from me, too. I have all this fun (gulp!) to look forward to at some point.

Well done. That is one of the very best sounding and most powerful boomboxes around. Unfortunately, the weak link, even though it is well constructed and solidly built with lots of metal, is that the deck on most of these simply do not work anymore. Luckily, yours did not have this issue, but I have seen many examples where the deck simply won't work right even after rebelting. There is a magnet pulley that loses magnetism and that part is no longer available anymore. I forget since it's been at least 5 years since I last worked on one, but I believe it is for the autoreverse feature, but I'm just going by memory here. What happens is that the attraction of the magnet causes it to rotate to a certain position in it's small axis based on the current function but loss of magetism results in that ring being in the wrong position which interferes with proper operation. This magnetism movement is described in depth in the service manual, for anyone that is interested in knowing more about it. Unfortunately, there is no workaround that I know of once this magnet is fubar'd. I once recapped the entire tape mechanism on a unit only to discover after rebelting that it had this issue. That annoyed me to no end.

Looks like yours is still in good shape, so cherish it. It's a rare beast to have a fully working unit, and I suspect getting rarer all the time.

Fantastic job T-STER!

These small decks are not easy to work on.

The most troublesome and evasive work I ever did was replacing belts on a Sony FH-11W double cassette deck.


I had to take all boards out to reach to the decks plus had to dismantle part of the deck to replace belts.

Scroll toward the end of this link....

https://boomboxery.com/forum/index.php/topic/17533-sony-fh/?hl=sony

Awesome I may have a crack at mine, I thought these were impossible but you give me hope!

Hi all.....after much work changing belts and fault checking the FH7 MkII, I have discovered the ribbon connector is damaged. It is missing 2 tines (which I probably did myself).

Cannot find any on ebay or in an obvious supplier.

Does anyone have a suggestion for where to find one?

I think you can just cut all the ribbons even across then strip them all and stick em back in the slots. I dont remember what they look like but if it's the simple ones its like aluminum wires side by side instead of a thin flat ribbon.

The pin is an arrow shaped staple that goes through the wire in the ribbon. Not sure if the wires themselves will be strong enough on their own.

I have been referring to this guide again today....my fat fingers are having trouble hooking the large fat belt around the flywheel. Very frustrating.

You get a sense of the complexity of these beasts when you work on them.

turnip said:

I have been referring to this guide again today....my fat fingers are having trouble hooking the large fat belt around the flywheel. Very frustrating.

You get a sense of the complexity of these beasts when you work on them.

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Buy yourself a cheap set of dental tools on ebay, infinitely easier for jobs like this. Once you have a set you will wonder how you managed without!