The timer switch is usually meant to be used with external timers. The idea is that if that switch is on play or record, it will automatically go into that respective function when the unit receives power.

I had a similar issue with wow and flutter. The tape recorder was from the 80's. The lubrication in the bushings throughout the mechanism was slightly sticky. Ended up doing an ultrasonic bath in IPA. Then lubed sliders with lithium grease and bushings with light machine oil. There was a dramatic improvement.

Excellent vid. Particularly enjoyed all the trial & error. 👍
Old mate there in the comments suggesting letting some tapes run for a few hours back 'n forth is a great idea and may show some improvement once those belts 'wear in' a bit.

Clean the pinch rollers or replace if they are hard. Lubricate the motor with oil. The white connectors must be pressed and the cables pulled out.

You've had all the fun from that machine. I would move on.
Was interesting to watch though!

I love to dabble in repairing older stereo gear and building custom speaker units and building custom crossover units. I'm not a professional and purely self taught, but I have successfully repaired countless components including Turntables, Cassette Decks,  CD Players, Portable Boomboxes, Graphic Equalizers and Mid Size all in one units. I just recently repaired a Sony HST-D105 all in one unit which required new belts and a new motor in the Cassette Decks, new CD drawer belt, new speaker relay and the Turntable power output connection re-soldered. It now works as good as new.

Those cheap mixed belts are made in China and are absolute crap because they are inconsistent in stretch and width uniformity and are only good for use as counter or take up spool belts. The best belts I have ever used are the high precision DeckTech belts from the UK. I installed a Decktech belt in my AIWA AD-f370 and the wow and flutter figures improved over standard. The wow and flutter is specified at .065% and now it's down to .040% and sometimes it goes down to .030% which is unheard of for a 2 head single capstan belt drive deck. I am about to replace the belts in my Rotel RD-960BX, Akai GX-F25, Akai GX-M10,  Yamaha KX-500 and Yamaha KX-130 decks with Decktech ones.

BTW I am from Tasmania and I am looking for a 12 volt CCW 2 speed 2000/4000 rpm Sankyo BFB2L41T motor or substitute if any will work. The motor has the following connections + - A B and there are two in my Sherwood CD-340B and Deck A is intermittently squealing. I put a drop of oil on the motor shaft and the squeal has gone, but it may possibly come back. Cheers, and thanks for a great video.

Nice video!

I'd be interested to see the power supply waveforms on an oscilloscope and see if they go up and down in time with the sound.

To test the decks without inserting a cassette, you can do it by feeling one of the nails of the plastic to see with which one the mechanism is activated.

I remember my friend’s older brother purchased a complete Sherwood system back in the late 80s. I was always a bit confused cause in NZ Sherwood was also the name of a wool company, and I wondered why they would make hifi gear.

I have same model working after service .From India

You push down on those white connectors and the ribbon cable pulls out, looks like that type anyway from a distance.

LOOKS LIKE THIS DECK ITS MADE FROM GOLDSTAR   TODAY  LG  . I LIKE SHERWOOD  NAME .

I was wondering if the motors just haven't been exercised in a long time. Maybe letting some old tapes autoreverse over and over for several hours might help them work better.
Seemed to work in my 8-track player when I let it sit to long.

Wow, I was looking for the same deck with exactly the same issue on the deck B, as in broken pin from the guiding part! To be honest, we may be in the same city, by the look of the Green Shed label, which (Green Shed) doesn't exist anymore for about almost two years now? If you are in Canberra please let me know if you can help with electronic part repair on three Teac A-300 that I have around with the more or less same issue, recording doesn't go as it should.

Maybe some of the caps that stabilize the speed are shot?

Did you ever get round to sorting this deck out?.  I had similar issues with a much older late 70s Sharp deck, replaced the belts, replaced a broken gear, replaced the idler tyres and lubricated everything but wow and flutter was still an issue. It actually did turn out to be the pinch roller which needed replacing. I just measured it with a set of calipers and bought a pack of five from Ebay that were the same dimensions and hole size and it worked. The motor needed a drop of oil too as it was a bit noisy but it now works fine, although getting it apart was absolutely horrendous compared to a more modern deck.

Given the cheap cost of replacement pinch rollers it might be worth a revisit and also worth some lubrication and a drop of oil in the motors. Can't hurt.

Ive been caught out by that connector when fixing my amp and wrecked it then found you puch down on the top bit and it releases the wires :s :/

I think it's the quality of the belts, and I don't know where to get decent belts that don't cost a fortune. I can see the "wow and flutter" in most of the belts I get from Amazon because they are so uneven. Given that, I don't think it's possible to fix anything that isn't direct drive anymore. I wish I'd seen this video before I bid my US $1 dollar on the one I got today!  I don't know why people are getting back into cassettes nowadays, or why I thought I wanted a dual deck!

It might get better if used for a while, it needs exercise so to speak - to loosen up.