Sony TC-K55II cassette deck. - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 5th Mar 2016, 7:04 pm

This must be the first time ever I've posted a topic in this part of the Forum.

I reckon this 1980s Sony cassette deserves a chance, although up to now I'm not having much success with it. The control functions are erratic, sometimes the reel motor will work when the appropriate buttons are pressed. On occasions the capstan motor will work also but will not switch off.

I doesn't help much not having a service manual for it.

Anyone got any experiences with this model?

DFWB.

sp10mk11 · 5th Mar 2016, 7:25 pm

I cannot remember for sure but do these machines have a door switch that tells the mecha control that the door is open or closed or is it a tape sensor switch that is moved when a tape is inserted, if these are old they could do with a good spurt of switch cleaner in them as they might be intermittent
Gary

paulsherwin · 5th Mar 2016, 7:38 pm

If this is a soft touch mechanically operated deck, the mechanism may need cleaning and relubricating. When bits of this start to stick all sorts of strange behaviour can happen. Unfortunately it's a pig of a job to do properly but you may be able to get away with a few drops of machine oil if you can work out what's sticking.

I assume you've already checked that all the belts are OK. Try giving all the pulleys a clean as belt slippage can cause this.

Michael Maurice · 5th Mar 2016, 8:08 pm

Service manual available here

paulsherwin · 5th Mar 2016, 8:21 pm

It looks as if it uses solenoids rather than mechanical assistance, so you don't need to worry about lots of bits of metal sticking together. You do have to worry about the microprocessor though

I would start by having a good search for dry joints around the micro, and checking all the voltage rails.

cmjones01 · 5th Mar 2016, 9:36 pm

We'be had one of these in the family since it was new. As I remember it, the capstan motor runs all the time the power is on. It is fully logic controlled but I can't remember if it detects a cassette being inserted.

Chris

FERNSEH · 5th Mar 2016, 10:21 pm

Good evening Gentlemen,
thanks for all your help. I've downloaded the service manual. After establishing that the power supplies are OK my attention will be drawn around the micro controller IC801.

DFWB.

Mooly · 6th Mar 2016, 9:37 am

I too used to have one of these and can also confirm the capstan motor runs continuously.

As a general fault (over many makes and models) the small reel motors can develop problems. Also check for dries around any hot running components such as reulators, motor drive transistors etc.

It was all a long time ago...

sp10mk11 · 6th Mar 2016, 5:54 pm

one other thing has come to me about these machines, the grease on the transport dries up, if you remove the flywheel you will see some PTFE parts and they will need removing and cleaning and then re-lubing, I would look at the control IC last, my experience of this type of transport is that if there is a fault it is normally due to a mechanical faliure Ie, switches and or mechanism
Gary

5th Mar 2016, 7:04 pm	#1
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Sony TC-K55II cassette deck. This must be the first time ever I've posted a topic in this part of the Forum. I reckon this 1980s Sony cassette deserves a chance, although up to now I'm not having much success with it. The control functions are erratic, sometimes the reel motor will work when the appropriate buttons are pressed. On occasions the capstan motor will work also but will not switch off. I doesn't help much not having a service manual for it. Anyone got any experiences with this model? DFWB. Attached Thumbnails

5th Mar 2016, 7:25 pm	#2
sp10mk11 Octode Join Date: Feb 2009 Location: Cornwall, UK. Posts: 1,275	Re: Sony TC-K55II cassette deck. I cannot remember for sure but do these machines have a door switch that tells the mecha control that the door is open or closed or is it a tape sensor switch that is moved when a tape is inserted, if these are old they could do with a good spurt of switch cleaner in them as they might be intermittent Gary

5th Mar 2016, 7:38 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,966	Re: Sony TC-K55II cassette deck. If this is a soft touch mechanically operated deck, the mechanism may need cleaning and relubricating. When bits of this start to stick all sorts of strange behaviour can happen. Unfortunately it's a pig of a job to do properly but you may be able to get away with a few drops of machine oil if you can work out what's sticking. I assume you've already checked that all the belts are OK. Try giving all the pulleys a clean as belt slippage can cause this.

5th Mar 2016, 8:08 pm	#4
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,225	Re: Sony TC-K55II cassette deck. Service manual available here __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

5th Mar 2016, 8:21 pm	#5
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,966	Re: Sony TC-K55II cassette deck. It looks as if it uses solenoids rather than mechanical assistance, so you don't need to worry about lots of bits of metal sticking together. You do have to worry about the microprocessor though I would start by having a good search for dry joints around the micro, and checking all the voltage rails.

5th Mar 2016, 9:36 pm	#6
cmjones01 Nonode Join Date: Oct 2008 Location: Warsaw, Poland and Cambridge, UK Posts: 2,679	Re: Sony TC-K55II cassette deck. We'be had one of these in the family since it was new. As I remember it, the capstan motor runs all the time the power is on. It is fully logic controlled but I can't remember if it detects a cassette being inserted. Chris __________________ What's going on in the workshop? http://martin-jones.com/

5th Mar 2016, 10:21 pm	#7
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Sony TC-K55II cassette deck. Good evening Gentlemen, thanks for all your help. I've downloaded the service manual. After establishing that the power supplies are OK my attention will be drawn around the micro controller IC801. DFWB.

6th Mar 2016, 9:37 am	#8
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Re: Sony TC-K55II cassette deck. I too used to have one of these and can also confirm the capstan motor runs continuously. As a general fault (over many makes and models) the small reel motors can develop problems. Also check for dries around any hot running components such as reulators, motor drive transistors etc. It was all a long time ago...

6th Mar 2016, 5:54 pm	#9
sp10mk11 Octode Join Date: Feb 2009 Location: Cornwall, UK. Posts: 1,275	Re: Sony TC-K55II cassette deck. one other thing has come to me about these machines, the grease on the transport dries up, if you remove the flywheel you will see some PTFE parts and they will need removing and cleaning and then re-lubing, I would look at the control IC last, my experience of this type of transport is that if there is a fault it is normally due to a mechanical faliure Ie, switches and or mechanism Gary