TEAC A3440 /REVOX A (HS) 77 - troubleshooting help please

[Lord_Xorrosho]

Greetings All
these two machines have been buried under a huge mountain of all kinds of stuff in my Dad's garage for the last 25 years minimum.not suprisingly they have a few problems,hopefully nothing too serious.any advice/tips mucho appreciated,cheers.

TEAC A3440

- only prob so far as can tell is that it won't play or record.it will fast forward and rewind fine,however when you go into play or record the tape just sits there not moving.you can gently "encourage" it with a finger but it soon gives up.
is this belt or motor trouble?

REVOX A/HS 77

right hand channel seems dead - any tips??

also have the Teac rx9 but dont have enough leads today to set it up and
try.aslo a bit pointless until the a3440 is working properly?!

[DOFFERY]

Most certainly a new capstan belt is required for the 3440 , as for the 77 without a few more tests difficult to judge. Is it dead on play only, any indication of a recording level ?

Colin

[ben]

check the following:
-lubrication (grease) on mechanics and pinch roller mechanism in particular.
-condition of rubber pinch roller. hard? shiny? cracked? dirty? bulging?
-condition of belts and rubber tyres, idlers etc.
-capstan - is it stiff? =bearing may need lubrication.

in general, after 25 years any machine will need an overhaul and partial strip down. the good news is that if the heads etc aren't worn, then this is usually all that's required to restore operation!

[Michael Maurice]

Hi

I live in North West London and know the Revox well, I can also help you with the Teac. If you're interested, send me a Private Message by clicking on my avatar (to the left of this reply)

[Lord_Xorrosho]

many thanks each -

the Revox shows no life at all on the right channel other than the meter light
works (a bonus in itself i guess) -hopefully this means the meter is ok,its a
fault in the amp section?

managed to d/l manuals and some other bits from "hifi engine" ,well
recommended.just in case anyone was unaware of it :

http://www.hifiengine.com/

so time to bite the bullet and get the screwdriver out...

thanks again all , have a trouble free bank holiday monday

[Lord_Xorrosho]

ahoy!

re Teac a3440 - drivebelt? wot drivebelt??do you mean that sticky black mess
all over everything inside the machine
well hopefully thats all thats wrong,which will be a right result.

the Revox a bit more involved,have it apart,am wondering if there are
some small seperate fuses for each amp/record stage,if one of them has
blown that will explain everything.time to consult the manual.if it doesnt
have these fuses am in the dark at at you mercies again..

all comments appreciated,ta

[Lord_Xorrosho]

any ideas on getting hold of blasted drive belt??

not much at all on the net,what little there is seems to be in the States.

is this one ok for an A3440 -

http://www.chsinteractive.co.uk/elec...pstan-teac.htm

- only has thier own part number not the Teac one (which is 55344680)

all help much appreciated

[DOFFERY]

I have the belts if required send me a PM.

Colin

[Michael Maurice]

The only fuses on the Revox are the mains input fuse (in fuseholder by mains voltage selector), 27V and 21V.

If the mains fuse has blown, the machine wont come on.

If 27V blows there will be no lights, no functions

If 21V has blown, you'll get no sound out of either channel, no capstan rotation and no end of tape bulb.

I think we can safely say that the fuses are not the problem.

Common to both record and playback is the playback card, its output stage is switched between input and tape, the fault may well be there but without a more thorough check I cant say where the fault lies.

Its best if you have a signal generator,

Connect it to the AUX in, set the input selector to AUX, set the input level to about 5 or 6, the volume to Max and balance to centre, no check the output, you should have a signal there, you probrably wont because of the fault. Using a scope or signal tracer, work back till you see a signal, then locate the faulty part.

What you may like to do, is to clean the switches with switch cleaner such as Servisol, this is not for the faint hearted, all the plug in boards have to come out, (remember where they came from) then the mother board needs to be removed.

Good luck

Michael

[Lord_Xorrosho]

thanks again for all help have PM'd ;-)

[Lord_Xorrosho]

muchos gracias Doffery,belt arrived quick-smart.
fitted straight away,all ok,but think there is mechanical or electrical problem,
possibly the capstan solenoid?? -
if i push the lever over it seems to work,otherwise nothing happens so
far as the spools turning goes,the solenoid plunger just stays in what i am assuming is an "off" position (see pic)


any hints tips advice please ??


cheers

L H

[DOFFERY]

Presume you have a tape on? If so do the "brakes release" when switched to play/record ? If so & wind/rwd. work you have a few possible problems , first check the
micro switch operated by the tape lever(auto stop)

From there your problems become a little nasty, it could be a spark filter , of which there are many on this machine, plus possibly the diode across the solenoid.

I can assure you if you don't know already the funtion switch viewed from the back is a nightmare. However check the above first ( I am assuming the motor itself is free ??) & we can go further later if required.

One last point, it is not unknown for the switch itself to be at fault.

Colin

[TIMTAPE]

A very common fault with these Teacs is when the pinch roller arm bearing grease dries out to glue. The symptom is the pinch roller not always moving up in play. If you help it it will sometimes pull in.

If so, you have to remove the arm from the pin (which is sometimes very difficult because it can be stuck solid. Some solvent can help. Sometimes a puller is needed to remove the arm) clean, relube and reassemble.

Cheers Tim

[Lord_Xorrosho]

thanks for those tips.will investigate.any more ideas please let me know.

for clarification :

the machine rewinds and fast-forwards perfectly,it just refuses to go into
play or record.

cheers

L H

[DOFFERY]

Yes but does the capstan motor run when in play/record, regardless of tape movement??
If not ......do the brakes on the side motors release when going to play & record
Colin

[Top Cap]

The capstan should be moving even with the machine set to OFF provided that the tape is laced up and the tape sensor arm (right hand side of deck) is operating its associated micro switches. Check the micro switches are not broken, there are two stacked together and operated by the rotating cam of the tape sensor arm.One does capstan motor control, the other initiates a STOP command.

[Lord_Xorrosho]

hi again Doffrey/Top Cap and thanks for posts sorry for delay in this post,everyday life getting in the way.
the capstan does spin when the machine is ON but "idle"
the brakes DO release when play is pressed

if its electronic fault im stuffed as too incopetant to do more than unsolder and replace a part - no test skills or anything :-(

do you mean this switch ( see pic) Teac part no 51300010

[TIMTAPE]

I cant be sure what you are saying. You say the capstan spins. Good. You also speak of the "capstan solenoid". There is no such animal.

You also posted a photo of the pinch roller solenoid and arm. Is this what you mean by the "capstan solenoid"?

With the machine off, you should be able to easily push the pinch roller up to the capstan shaft and when you let it go, it should spring back down all by itself. Does it?

The total travel of the pinch roller up or down should be about 1/4"

Cheers Tim

[DOFFERY]

I think "Lord" is referring to the pinch wheel solenoid Tim, as all else seems to work apart from the pinch wheel , does this solenoid work, it would appear from previous posts no!!! If so the question as mentioned of the grease requires attention , after that we are back to an electrical fault requiring some attention.
As has been mentioned before "Lord" try pushing the pinch wheel up to the capstan when machine set for operation .

Colin

[Lord_Xorrosho]

sorry to be a dumbass - indeed i mean the pinch wheel solenoid or *** it is called.
the pinch wheel can be easily pushed into position,yes about 1/4" movement.
if i put the machine into play or record and then push the solenoid lever/plunger in by finger then the spools turn normally.whether it IS playing or recording dont know as its not rigged up to an amp at the mo,and no response on the vu meters - but it looks promising anyway,tape may be blank hence no needle movement?
will get that arm off and re-lube and see what occurs.
many thanks for your help and patience.