ITT KP821(BSR) stuck platter - UK Vintage Radio Repair and Restoration Discussion Forum

plaka78 · 20th Feb 2017, 7:26 pm

I had a pm today referring for help with a stuck BSR platter

I can have these Turntables off within minutes however hard they have seized with no damage whatsoever.

Slighty twist the piece of metal that holds the slider bar on the bottom (red arrow, see picture) remove this slider bar out of the way. Remove spindle, pour boiling water down the centre of the turntable (pour Boiling water from the bottom side) Also if the cam is seized solid pour boiling water around the centre. This has never failed for me and like I said you can get the turntable off within a few minutes.

'LIVEWIRE?' · 25th Feb 2017, 2:28 pm

I hadn't thought of using boiling water before, but have just done so on a BSR C123R with a seized platter and cam gear. Both came off easily after pouring boiling water down the respective bearings, so it's a case of thoughroughly drying the affeced parts, cleaning out any surplus grease & relubricating the parts involved . The deck should then be in 100% working order. Many thanks for the tip.

Welsh Anorak · 25th Feb 2017, 4:41 pm

A little more elegant than my method of using a blowtorch!
However the one I did last week wouldn't release the spindle either so drastic measures were called for.
Glyn

Audio1950 · 26th Feb 2017, 12:16 am

An even less messy way is to hold a soldering iron against the base of the spindle, which will soften the old grease. Once that's out, put the soldering iron down the spindle hole, and after a few seconds, the turntable will also come off.

GP49000 · 26th Feb 2017, 3:05 am

However if it's one of the increasingly cheaply-made BSRs with the plastic platter, a torch or soldering iron could be a bit much!

Some of the plastic platters are unsalvageable. People who would leave the phonograph in a sunny window could find the heat has SHRUNKEN the plastic. The thin metal sleeves that serve as "bearings" aren't enough to prevent the shrunken plastic from seizing onto the platter bearing shaft.

'LIVEWIRE?' · 26th Feb 2017, 9:59 am

The C123R (and, I believe, the C129R) have plastic turntables. Luckily the boiling water treatment didn't warp the turntable, so, once I've cleaned, degreased aand relubricated the parts involved (including the ball race and it's associated washers, all of which were stuck together as if glued) the 129 should run as good as it did when new!

AndiiT · 26th Feb 2017, 4:32 pm

Hi, a great tip. I find that an application of lighter fluid and then gentle heat from a hair dryer usually softens the grease enough to allow the seized parts to be removed.
But as I was once told when relating to arithmetic and cookery "always stick to the method that you know works"

Andrew

'LIVEWIRE?' · 26th Feb 2017, 5:55 pm

Relating to the above, would Electrolube High Temperature grease - HTG50T (CPC SA00647) be suitable for relubricating bearings on this and other turntables? I currently have a rather old tube of Electrolube grease,on the tube of which I can no longer read any of the details, and have used this on turntables & tape decks, etc. for years, but have no idea whether it is the same product or not. At one time Molykote was, IIRC, specified by Blaupunkt for lubricating sliding surfaces, etc. I've just checked on eBay, and various types of this are still available, so maybe I should go for that instead. In a domestic environment the HTG may be a bit of an overkill. What do others think?

'LIVEWIRE?' · 26th Feb 2017, 7:05 pm

The stop/start/reject lever is stuck in the stop position on the BSR C123R. A further application of boiling water into the various pivot points has freed up the sliding plate which is activated via the cam gear, but has had little, if any, effect on the stop/start/reject lever. Temorarily removing the link between this (plastic) lever and the rest of the mechanism proves that the problem is somewhere in the sliding plate assembly, but I can't determine where, or which part(s) are the cause. Can anyone advise what to do next, please?

'LIVEWIRE?' · 27th Feb 2017, 11:48 pm

Having looked at another, similar, BSR Deck (a C137), it appears that a metal part which should slide and pivot freely doesn't in the C129, but as yet, I can't see why this is so. Maybe further dismantling of the mechanism is required. The part in question is just visible about midway down the RH side of the picture in post#1. It's item 41 - the Cutoff slide, which links to iem 87, the Detente Plate. These are above the Main Sub-plate (item 45) (Descriptions and item nos. taken from the service manual for the similar C141R1, which is available from Vinyl Engine

'LIVEWIRE?' · 2nd Mar 2017, 12:28 pm

The problem is indeed due to the Cutoff Slide and Detente Plate, caused by our old friend 'hardened grease'. A squirt or two of servisol, followed by boiling water poured between the slie and the plate on which it's mounted has partially restored correct operation, but there is still a tendency for the lever to stick between the start and reject positions, but I'm (slowly) getting there!

25th Feb 2017, 2:28 pm	#2
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: ITT KP821(BSR) stuck platter I hadn't thought of using boiling water before, but have just done so on a BSR C123R with a seized platter and cam gear. Both came off easily after pouring boiling water down the respective bearings, so it's a case of thoughroughly drying the affeced parts, cleaning out any surplus grease & relubricating the parts involved . The deck should then be in 100% working order. Many thanks for the tip.

25th Feb 2017, 4:41 pm	#3
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,921	Re: ITT KP821(BSR) stuck platter A little more elegant than my method of using a blowtorch! However the one I did last week wouldn't release the spindle either so drastic measures were called for. Glyn

26th Feb 2017, 12:16 am	#4
Audio1950 Dekatron Join Date: Nov 2008 Location: Whittlesey, near Peterborough, Cambridgeshire, UK. Posts: 3,761	Re: ITT KP821(BSR) stuck platter An even less messy way is to hold a soldering iron against the base of the spindle, which will soften the old grease. Once that's out, put the soldering iron down the spindle hole, and after a few seconds, the turntable will also come off.

26th Feb 2017, 3:05 am	#5
GP49000 Hexode Join Date: Mar 2012 Location: Sonoma County, California, USA. Posts: 405	Re: ITT KP821(BSR) stuck platter However if it's one of the increasingly cheaply-made BSRs with the plastic platter, a torch or soldering iron could be a bit much! Some of the plastic platters are unsalvageable. People who would leave the phonograph in a sunny window could find the heat has SHRUNKEN the plastic. The thin metal sleeves that serve as "bearings" aren't enough to prevent the shrunken plastic from seizing onto the platter bearing shaft.

26th Feb 2017, 9:59 am	#6
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: ITT KP821(BSR) stuck platter The C123R (and, I believe, the C129R) have plastic turntables. Luckily the boiling water treatment didn't warp the turntable, so, once I've cleaned, degreased aand relubricated the parts involved (including the ball race and it's associated washers, all of which were stuck together as if glued) the 129 should run as good as it did when new!

20th Feb 2017, 7:26 pm	#1
plaka78 Pentode Join Date: Jul 2007 Location: Salisbury, Wiltshire, UK. Posts: 174	ITT KP821(BSR) stuck platter I had a pm today referring for help with a stuck BSR platter I can have these Turntables off within minutes however hard they have seized with no damage whatsoever. Slighty twist the piece of metal that holds the slider bar on the bottom (red arrow, see picture) remove this slider bar out of the way. Remove spindle, pour boiling water down the centre of the turntable (pour Boiling water from the bottom side) Also if the cam is seized solid pour boiling water around the centre. This has never failed for me and like I said you can get the turntable off within a few minutes. Attached Thumbnails

26th Feb 2017, 4:32 pm	#7
AndiiT Octode Join Date: Aug 2005 Location: Saltburn-East, Cleveland, UK. Posts: 1,786	Re: ITT KP821(BSR) stuck platter Hi, a great tip. I find that an application of lighter fluid and then gentle heat from a hair dryer usually softens the grease enough to allow the seized parts to be removed. But as I was once told when relating to arithmetic and cookery "always stick to the method that you know works" Andrew

26th Feb 2017, 5:55 pm	#8
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: ITT KP821(BSR) stuck platter Relating to the above, would Electrolube High Temperature grease - HTG50T (CPC SA00647) be suitable for relubricating bearings on this and other turntables? I currently have a rather old tube of Electrolube grease,on the tube of which I can no longer read any of the details, and have used this on turntables & tape decks, etc. for years, but have no idea whether it is the same product or not. At one time Molykote was, IIRC, specified by Blaupunkt for lubricating sliding surfaces, etc. I've just checked on eBay, and various types of this are still available, so maybe I should go for that instead. In a domestic environment the HTG may be a bit of an overkill. What do others think?

26th Feb 2017, 7:05 pm	#9
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: ITT KP821(BSR) stuck platter The stop/start/reject lever is stuck in the stop position on the BSR C123R. A further application of boiling water into the various pivot points has freed up the sliding plate which is activated via the cam gear, but has had little, if any, effect on the stop/start/reject lever. Temorarily removing the link between this (plastic) lever and the rest of the mechanism proves that the problem is somewhere in the sliding plate assembly, but I can't determine where, or which part(s) are the cause. Can anyone advise what to do next, please?

27th Feb 2017, 11:48 pm	#10
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: ITT KP821(BSR) stuck platter Having looked at another, similar, BSR Deck (a C137), it appears that a metal part which should slide and pivot freely doesn't in the C129, but as yet, I can't see why this is so. Maybe further dismantling of the mechanism is required. The part in question is just visible about midway down the RH side of the picture in post#1. It's item 41 - the Cutoff slide, which links to iem 87, the Detente Plate. These are above the Main Sub-plate (item 45) (Descriptions and item nos. taken from the service manual for the similar C141R1, which is available from Vinyl Engine Last edited by 'LIVEWIRE?'; 27th Feb 2017 at 11:56 pm. Reason: To add further information which may be helpful!

2nd Mar 2017, 12:28 pm	#11
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: ITT KP821(BSR) stuck platter The problem is indeed due to the Cutoff Slide and Detente Plate, caused by our old friend 'hardened grease'. A squirt or two of servisol, followed by boiling water poured between the slie and the plate on which it's mounted has partially restored correct operation, but there is still a tendency for the lever to stick between the start and reject positions, but I'm (slowly) getting there!