Rotel RCX 820 - UK Vintage Radio Repair and Restoration Discussion Forum

Michael Maurice · 22nd May 2012, 12:58 pm

This is a receiver with a cassette deck built in and it is the cassette deck i'm having difficulties with.

The belts had turned to goo so after cleaning the mess up and replacing them I expected it to work.

FF and Rew is OK but if play is selected the plate with the heads moves up but not enough to engage and no the pause button is not on.

The mechanism is operated by a cam gear driven off the flywheel which moves a lever (arrowed) I've checked the levers, they are not worn or damaged. Its as though there should be a collar on the top of the stud that moves the head block.

Does anyone know what the cause might be?

TIMTAPE · 22nd May 2012, 9:42 pm

Michael,

Seems like your first guess is right. By how much does the head plate fall short? Is the missing part possibly trapped somewhere in the mech?

Tim

Nickthedentist · 22nd May 2012, 11:18 pm

How puzzling!

Does the pause button have any effect on the head plate?

And if you give the plate a gentle shove in the right direction, does it then latch and the machine play normally?w

If so, can you do the same thing by rotating the lever with the stud on it, or not?

Presumably, there wasn't any "goo" in the region of the actuating post, implying there might have been some rubber part (sleeve on the stud or "grommet" on the plate) that's no longer present?

Nick.

Michael Maurice · 23rd May 2012, 12:17 am

The pause button doesn't do anything, but i think I may have found the answer.

If you look at picture 2 in post 1, you'll see a little black bit of stout wire which actually is a spring.

The other end is under the head block where the base is plastic and this plastic has broken. I'm fabricating a repair and am waiting for glue to dry.

I'll post the result tomorrow

Refugee · 23rd May 2012, 12:52 am

My solution would have been to find a drill bit in my 12 volt drill kit that is slightly smaller than a sewing needle and drill through the plastic and plate and simply hammer the needle in and use the little disk cutter to trim it. I have found that glue does not usually set very well on plastic.

TIMTAPE · 23rd May 2012, 4:07 am

Ah, the old wire and super glue trick. I've used it many times to repair broken, brittle plastic parts in various mechanical devices.

Yesterday I repaired a power switch on a Revox A700. The square peg on the end of the switch broke away with the user press button. I drilled a small hole in both parts and joined them together using part of a paper clip, suitably roughened to gain more grip with the super glue.

I'm a big fan of paper clips but almost never for their intended purpose!

Good luck Michael.

Michael Maurice · 25th May 2012, 1:16 am

Well the glue didn't work, well it did for a few hour!

But Refugees idea of drilling a hole did bring something to mind. Suppose I bent the spring end by 90 degrees and drilled a hole in the plastic, that could be a solution, but can I bend the spring and if so can I just use pliers or do I have to do it in a special way?

Its a real pain because it means a total strip down again!

Michael Maurice · 25th May 2012, 9:47 am

Ok well the solution I implemented was to bend the end of the spring which sat in the plastic head block by 90 degrees, I then marked where this end would fit, drilled a hole using a 0.8mm PCB drill bit, slightly enlarged it and fitted the spring in there.

The spring is quite strong which is why the flimsy plastic head block probably failed in the first place.

I just hope my customer appreciates it.

22nd May 2012, 12:58 pm	#1
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,224	Rotel RCX 820 This is a receiver with a cassette deck built in and it is the cassette deck i'm having difficulties with. The belts had turned to goo so after cleaning the mess up and replacing them I expected it to work. FF and Rew is OK but if play is selected the plate with the heads moves up but not enough to engage and no the pause button is not on. The mechanism is operated by a cam gear driven off the flywheel which moves a lever (arrowed) I've checked the levers, they are not worn or damaged. Its as though there should be a collar on the top of the stud that moves the head block. Does anyone know what the cause might be? Attached Thumbnails __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

22nd May 2012, 9:42 pm	#2
TIMTAPE Octode Join Date: Jul 2006 Location: Perth, Western Australia Posts: 1,969	Re: Rotel RCX 820 Michael, Seems like your first guess is right. By how much does the head plate fall short? Is the missing part possibly trapped somewhere in the mech? Tim

22nd May 2012, 11:18 pm	#3
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Rotel RCX 820 How puzzling! Does the pause button have any effect on the head plate? And if you give the plate a gentle shove in the right direction, does it then latch and the machine play normally?w If so, can you do the same thing by rotating the lever with the stud on it, or not? Presumably, there wasn't any "goo" in the region of the actuating post, implying there might have been some rubber part (sleeve on the stud or "grommet" on the plate) that's no longer present? Nick.

23rd May 2012, 12:17 am	#4
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,224	Re: Rotel RCX 820 The pause button doesn't do anything, but i think I may have found the answer. If you look at picture 2 in post 1, you'll see a little black bit of stout wire which actually is a spring. The other end is under the head block where the base is plastic and this plastic has broken. I'm fabricating a repair and am waiting for glue to dry. I'll post the result tomorrow __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

23rd May 2012, 12:52 am	#5
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Rotel RCX 820 My solution would have been to find a drill bit in my 12 volt drill kit that is slightly smaller than a sewing needle and drill through the plastic and plate and simply hammer the needle in and use the little disk cutter to trim it. I have found that glue does not usually set very well on plastic.

23rd May 2012, 4:07 am	#6
TIMTAPE Octode Join Date: Jul 2006 Location: Perth, Western Australia Posts: 1,969	Re: Rotel RCX 820 Ah, the old wire and super glue trick. I've used it many times to repair broken, brittle plastic parts in various mechanical devices. Yesterday I repaired a power switch on a Revox A700. The square peg on the end of the switch broke away with the user press button. I drilled a small hole in both parts and joined them together using part of a paper clip, suitably roughened to gain more grip with the super glue. I'm a big fan of paper clips but almost never for their intended purpose! Good luck Michael.

25th May 2012, 1:16 am	#7
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,224	Re: Rotel RCX 820 Well the glue didn't work, well it did for a few hour! But Refugees idea of drilling a hole did bring something to mind. Suppose I bent the spring end by 90 degrees and drilled a hole in the plastic, that could be a solution, but can I bend the spring and if so can I just use pliers or do I have to do it in a special way? Its a real pain because it means a total strip down again! __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

25th May 2012, 9:47 am	#8
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,224	Re: Rotel RCX 820 Ok well the solution I implemented was to bend the end of the spring which sat in the plastic head block by 90 degrees, I then marked where this end would fit, drilled a hole using a 0.8mm PCB drill bit, slightly enlarged it and fitted the spring in there. The spring is quite strong which is why the flimsy plastic head block probably failed in the first place. I just hope my customer appreciates it. __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/