Akai X330 Rewind Problem

[hsbhachu3d]

Alright,here goes, This might be a long one.

I got an x-330 in great condition. It was sold as 'spares or repairs' for £145 which I thought was a bit pricy but well, I got it. anyway, Despite the seller giving adescription of how he replaced the belts and it stopped working at some point, I opened the deck to find a small part of the main control board broken off and glued. I took it apart and put it back together without the board but made all the connections as needed. even as it was a double sided board and made the links to the back and front of the board i.e. the ffw capacitor linked to the back and front part of the board. I set it back up and the play started taking up, and the fast forward started working too. unfortunately for the rewind, i hear a slight humming from the motor as it tries to rewind ( this is a 3 motor deck )

The spindle is absolutely free and can be turned by hand. I have gone through the service manual, which is avaliable on HifiEngine, It tells me to check the relay and the caps in the rewind section. So I did. replaced the 3 or so caps and same thing. I swapped the forward relay and rewind relay, sincethey were the same and forward and take up works find but rewind is still the same, dead witha bit of hum. I put all the old caps in because they looked fine, to me anyways.

I did get a reply from the seller saying how he accidentally broke the board whilst putting new belts in. However, he says the deck functioned properly, play, rewind and record. Now I am stuck not knowing what to do. Also I did check the voltages at the relay, and at the motor. 30V AC on a Heathkit Multimeter. these Voltages are similar towhat I checked on the take up motor. I still don't think the motor is burnt however.

[hsbhachu3d]

Here are the datasheets and schematics that help .

[Diabolical Artificer]

Apart from the RW problem, I'd have asked for my money back. As it's been got at, finding fault's are going to be harder, who know's what else he's done. The sticking back together of the broken board says a lot about the repairer's skill level.

Check the motor winding's continuity, it's capacitor and it's brushes if it has them.

Andy.

[hsbhachu3d]

That was fair, but instead of telling me he broke the board, he implied to me that it'll be difficult to fix it. Anyway, the progress so far:

The take up motor is the same as the supply one which of course doesn't turn. The schematic and information from the manual tells me that they're the same motors, one is reverse wound I think to run in opposite direction.

However, if I were to disconnect all 4 wires (yellow, green, blue and red) and connect them to the same ones from the motor that doesn't work, it should run, if the fault is in the board. What I did was I disconnected the forward motor and connected the 4 points from the rewind corresponding to the colours and plugged it in, knowing that if I were to press play or fast forward, the rewind motor which is the same as forward one should run if it was fault free. But no, it did the same thing as it was doing whilst connected on its own line. Attempting to turn which slight AC humming from it. So I'm still a small fraction paranoid that it doesn't have a fault, but shall I get a replacement and see? please advise.

[TonyDuell]

It appears from the schematic you posted that there is a 0.47uF capacitor which is part of the rewind motor but elsewhere for the takeup motor. If that's the case, I don't think you can simply swap the motor connections.

Have you checked the continuity of the windings for the rewind motor? What about the capacitors that appear to be part of it (the ones associated with the mains frequency switch)?

[julie_m]

They look like standard split-phase induction motors. This is where one of the windings is fed directly, the other via a capacitor; and depending which coil gets the direct supply and which one gets the phase-shifted supply, the armature rotates either clockwise or anticlockwise. If so, there's no good reason not to use identical, reversible motors.

In PLAY, there should be a resistance in series with each motor (probably more resistance on the supply spool motor since the capstan is working with it to create back tension, but opposing the take-up spool motor trying to wind up the tape); which gets shorted out when WINDing towards its spool and probably disconnected altogether so the motor is unpowered when winding away from it.

But I haven't studied the diagram in the most painstaking detail, and I haven't got the machine in front of me, so I could be wrong .....

[hsbhachu3d]

Hi all, some progress after staying up all night. Just got some rest after putting the machine back together and after checking continuity of the motor, I noticed that one of the coils was NIL. 2 hours into painstakingly starting under a magnifying glass at the exposed winding, I saw 2 cuts that the seller has obviously made as he must've used a sharp object trying to lift the chassis. So I carefully lifted the 2 wires, heated my 150 watt weller gun and soldered them with other little strands of bare wire to support individually. I coated them with standard clear thinner based nail varnish and put the motor back in and it started running. 100% to the mark. I have some other issues with it that I will post separately. Thank you.

[Diabolical Artificer]

Good to hear your making progress, hope there's not too much more damage.

Andy.

[hsbhachu3d]

Hi, I have posted separately and I havent had any replies and I am at a stand still. https://www.vintage-radio.net/forum/...d.php?t=127133