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-   -   Advice concerning Philips N4414 reel to reel machine (https://www.vintage-radio.net/forum/showthread.php?t=167065)

ApogeeUK 22nd May 2020 9:27 pm

Advice concerning Philips N4414 reel to reel machine
 
Hello,

First time poster hoping for some wisdom from the collective expertise here. I have found one of the above machines whilst clearing out my wife's family home. It's evidently been gathering dust for decades. It's a lovely looking thing and, initially anyway, powered up okay. However, when we had trouble getting it up to speed we ignorantly decided to tamper with (what we know now! :'( ) is the voltage adapter on the back of the machine. Now, of course, the player is dead. Could any kind soul tell us if the damage is irrepairable or have we just likely blown a fuse?

Any input gratefully received.

Gary

paulsherwin 22nd May 2020 10:26 pm

Re: Advice concerning Philips n4414 reel to reel machine
 
What a pity. I assume you have changed the voltage selector to 120V then connected the recorder to 240V mains. If you are very, very lucky then an internal fuse will have blown, but it's highly likely that major damage will have been done which may or may not be repairable. By all means take off the cover and replace any blown fuses, but don't get your hopes up.

A specialist may be able to repair it, but the cost may be more than it's worth at commercial rates. Recorders like this fetch maybe £50 in good working conditoon.

It probably didn't run properly because it needed new belts and a relube.

ApogeeUK 22nd May 2020 10:42 pm

Re: Advice concerning Philips n4414 reel to reel machine
 
Okay, many thanks for the reply. :):)

Michael Maurice 22nd May 2020 10:53 pm

Re: Advice concerning Philips n4414 reel to reel machine
 
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There is a 250mA fuse on the mains side of the transformer, you MUST fit the correct type.

An example is this from RS, but it is not a thermal fuse which ideally you should have.

This fuse must be soldered in, if you cannot do this, then you should find someone who can.

Its possible that due to the low value fuse, that's all that has blown, otherwise you're looking at having the transformer rewound which is expensive.

Once you've got the machine working, you must replace the belts and lubricate the spooling motors.

Please let us know how you get on

paulsherwin 22nd May 2020 10:57 pm

Re: Advice concerning Philips n4414 reel to reel machine
 
Michael has more experience with these than I have, so he's almost certainly right.

ApogeeUK 23rd May 2020 9:28 am

Re: Advice concerning Philips N4414 reel to reel machine
 
Okay, I will look into it and hope that's all it is. Thanks again guys. Will let you know the result.

ApogeeUK 28th May 2020 1:29 pm

Re: Advice concerning Philips N4414 reel to reel machine
 
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Success!! ;D

Thanks to Michael kindly providing an actual red arrow pointing to the target spot I was able to replace the fuse and (perhaps miraculously) the machine now powers up. I've attached a couple of images. My soldering won't be winning any awards but now the machine is (mainly) working again. :) Wrestling ther transformer back into position was a pain but other than that it was pretty straightforward.

So the original problem remains. The tape is not playing at the correct speed. I can get the right hand take up motor turning okay (albeit with a flick of the hand) but then the music emitted by the built-in speakers is way too fast. Sometimes it slows right down and stops. I know you mentioned to replace the drive belts and I've now ordered some and also plan to lubricate as suggested and I've found an old manual telling me how to do this. Any recommendations for a suitable oil? The research I've done on this throws up contradictory suggestions?

I'm pretty confident now I can get this beautiful machine functioning properly and I'm very grateful for the help received :thumbsup:

Thanks so much!

jamesperrett 29th May 2020 12:08 am

Re: Advice concerning Philips N4414 reel to reel machine
 
Sounds like the tape isn't making contact with the capstan/pinch roller properly. Is the capstan turning and is the pinch roller pushing the tape against the capstan?

Michael Maurice 29th May 2020 7:44 am

Re: Advice concerning Philips N4414 reel to reel machine
 
As James has said, check that the pinch roller is making contact with the capstan shaft, it must be moving up to it otherwise you wouldn't hear anything.

Check the capstan belt, if its loose, change it, they can cause all sorts of weird and wonderful problems.

Check the speed of the capstan, this should be running all the time the machine is switched on, does it speed up or down when you change speed? You will have to remove the top covers to see it properly.

If yes, then we'll have to do more tests

If no then you've got a fault with the capstan servo.

ApogeeUK 29th May 2020 10:03 am

Re: Advice concerning Philips N4414 reel to reel machine
 
Thanks guys. Will make that the focus of my enquiry.

ApogeeUK 2nd Jun 2020 4:23 pm

Re: Advice concerning Philips N4414 reel to reel machine
 
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Okay, so I've opend her back up, swapped all the drive belts for new and oiled the capstan wheel, the pinch roller and the motors. The capstan wheel turns quietly and very steadily. When not loaded with tape being played on a reel both motors seem fine, too. Alas, the problem persists.

After close study it looks like the real issue appears to lie with the mechanism that's designed to lift the pinch roller into position. Upon pressing play, the motor turns but this elongated mount part shows no movement at all. The tape is pulled across the heads unhindered by any contact from the rubber wheel. I can physically lift it upwards into contact by pushing down on the counterweight on the left and this definitely slows the sound down from chipmunk speed, but whatever process is designed to do this automatically and with precision doesn't appear to be functioning.

At first I thought there might be another belt missing (I had one left over) but after studing a schematic this doesn't seem to the be the case - There should be one belt for the capstan, one each for the two motors and one for the tape counter.

If someone could give me a clue where to concetrate my efforts next that would be great. I frankly thought it doubtful I'd get this far, so once again, much appreciated.

jamesperrett 3rd Jun 2020 1:56 am

Re: Advice concerning Philips N4414 reel to reel machine
 
A common issue on other makes is dried up grease in the mechanism which makes it stiff. The other thing to check is whether the solenoid is actually working. Does it try to move? Is there any voltage on the coil in play mode?

Michael Maurice 3rd Jun 2020 9:54 am

Re: Advice concerning Philips N4414 reel to reel machine
 
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I've not had dried up grease affect the mechs on these machines myself.

When you move the pinch roller by pressing down on the counterweight, does it move freely? If so your fault is likely to be electrical. Check the plunger of the solenoid, does it move freely? If you manually move it, does it lift the pinch roller?

Look at the diagram attached, the red line shows the path of the current in play.

Whilst depressing play and keeping it in play, ensure the pause button is not in. The 'A' is from the power supply and should be around 20-24V it must be there otherwise the capstan motor wouldn't run and brake solenoid wouldn't operate.

Now with a meter check the contact SK604, there should be 20V or so on both contacts. If there is, then check the voltage on both contacts of the capstan solenoid. If there is 0V on both terminals, the check Diode D208, there should be roughly 20V on both sides. If there is, you have a broken wire or connection between the board and the solenoid. If there is 20V on both terminals of the solenoid then you have a ground problem.

If you have 20V on one terminal of the solenoid and 0V on the other, it means either the solenoid is open circuit or jammed. You can check if the solenoid is ok by doing a resistance check between the terminals, you should get a reading, though I cant tell you exactly what that might be, probably a couple of hundred ohms.

Please do your tests and report back.

Michael Maurice 3rd Jun 2020 10:01 am

Re: Advice concerning Philips N4414 reel to reel machine
 
One thing, looking at the diagram again. Does the brake solenoid operate when you push play? If so do the voltage check on the solenoid. If thee is 0v on both terminals, carry out the resistance check. If it gives 0 resistance then it might be that Diode D201 is short circuit and D208 open circuit. Remove them both and check whether D201 is short circuit. if it is replace both diodes. The BA217 used in both these positions is obsolete, but an 1N4148 or an 1N4007 can also be used.

ApogeeUK 3rd Jun 2020 4:22 pm

Re: Advice concerning Philips N4414 reel to reel machine
 
Wow, that's wondefully detailed. Thanks a million. I'll dig out my multimeter this weekend. :):)

Gary

ApogeeUK 10th Jun 2020 10:22 am

Re: Advice concerning Philips N4414 reel to reel machine
 
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So this post takes the form of a delighted victory lap :)

Yesterday afternoon I finally got round to another exploration of the insides of the N4414. A short while later I was listening to the great Bluesman Josh White on this beautiful Reel to Reel which now works PERFECTLY!

My wife and I were both amazed at the excellence of the sound quality and I'm so happy I persisted, especially given the machine might have been on its way to the recycling centre.

Michael, I can't thank you enough for taking the time to detail exactly what I should be looking for repair-wise. My electronics know-how is pretty basic but your instructions allowed me to quickly hone in on the problem. After some careful study I was able to confirm the voltages on the push button side of the machine were correct and so proceeded to unscrew the main motor section from its mount. When I started properly investigating the solenoid mechanism at the rear a major anomaly stood out almost immediately.

The black rectangular block (pictured), part of the mechanism that lifted the pinch roller, was out of position. At first I thought it had broken away from its plastic mount but then saw there was an identical component just behind it (also pictured) and this one was secured by a metal band. The misaligned one had somehow come loose. I don't know quite how this could have been knocked out of place as it took a fair bit of leveraging with a screwdriver to snap it back in, but once I'd done so the pinch roller suddenly worked as it was meant to.

There's no way I would have noticed this issue had I not been following your step by step diagnosis. So, again, MANY thanks. It's very much appreciated. It's a great joy to have this machine working again. I'd read on numerous occasions how many felt this technology produced a superior sound and now I believe it.

It just goes to show that knowledge and experience, even in the hands of a layman, can get the right result.

Massive kudos to you and your very kind community. :clap:

Michael Maurice 10th Jun 2020 1:42 pm

Re: Advice concerning Philips N4414 reel to reel machine
 
I am pleased that you’ve fixed it and that I’ve been able to help you. Keep the heads clean and enjoy it.


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