RX-5150 heads stuck in engaged position

Hi all,

First time posting here and hoping for some advice from the Panasonic experts here. I have a Panasonic RX-5150 that I bought recently, and upon initial testing all of the cassette functions were not working. I assumed bad belts. Also, the tray wouldn't open all the way when eject was pressed. But when I tried to open it up, I realized that the heads and capstan were engaged. I had to press them down with a small screwdriver so that the tape would tilt out far enough to get a hold of it and pull it out (it had the tape in it when I got it). I've opened it up and have the cassette unit out. It looks like all the belts are there (at least they're not broken or melted). But I can't figure out why the heads are still engaged and won't retract (and stay that way). Any ideas or suggestions as to what might be the problem? Any and all replies will be much appreciated. Thanks.

Try turning the flywheel around to see if the mechanism will reset.

jimmyjimmy19702010 said:

Try turning the flywheel around to see if the mechanism will reset.

Click to expand...

Bingo! It did reset. Thank you! But is that all it needs to resume normal function? Should it work properly if I reassemble it, or does it indicate a problem that might reoccur?

jimmyjimmy19702010 said:

Try turning the flywheel around to see if the mechanism will reset.

Click to expand...

Bingo! It did reset. Thank you! But is that all it needs to resume normal function? Should it work properly if I reassemble it, or does it indicate a problem that might reoccur?

Edit: Sorry for the double post. Can posts be deleted here?

It indicates a possible issue with the main drive belt (stretched) that runs from the motor and the flywheel or an issue with the motor.

Complete overhaul should be done for best results 😉


Bad Boy Bill

I'm sure you're right, Bad Boy Bill. I did reconnect everything, just to see if it even works at all, and at least it is playing a tape. Couple things though. It did stop a couple times when I pressed play. Ran a second and then nothing. Also, it completely stopped working once (heads engaged but then nothing--buttons wouldn't lock or anything), and I had to depress the heads so that it would eject far enough to get the tape out. Then I rotated the flywheel again to reset, and it's working okay again and playing a tape right now.

Could I ask for some suggestions? Can anyone recommend a good source for belts (or should that even be my first guess as to what's causing this issue)? Are they hard to replace on this unit? Also, I downloaded a service manual for an RX-5150LS. Is that the same model (or at least the same manual)? Thanks in advance for any and all advice.

The guys have already given you good advice. The reason you have to press the heads down is because the main drive belt is slipping. This deck employs a servo drive system. The mechanical action of engaging and retracting the heads depend upon the energy provided by the rotation of the flywheel assembly. This mechanical action also imparts a momentary drag/resistance on the rotating assembly, which with a properly functioning belt is easy to overcome. However, if the belt is slipping, then the drag might be too much to overcome before slippage and the mechanism gets stuck in the last position. If the belt is structurally OK and simply suffers from deterioration of the surface layer, you might be able to restore function by cleaning the drive belt with isopropyl alcohol. To do a proper job, you should remove the belt and scrub it vigorously by a IPA soaked q-tip and/or tough paper towell, or something that will rub off the slick/powdery outer layer. You will notice your q-tip and/or paper towells turning black. When you are satisfied that the surface texture has restored some amount of "grip" you can reinstall it. Deterioration of belts is a very common issue. Sometimes, they turn into tar-like goo. Sometimes, they get hard/brittle and sometimes, they just lose their rubbery composition. There are other products you can try such as belt conditioner, but in my opinion, they are just a temporary band aid and if a cleaning with IPA doesn't restore it, then the belt should siimply be replaced instead of applying foreign compounds to the belts. Think of old car tires... they simply don't have the flexibility or grip they once used to have. The RX-5150LS would have differences in the electronics although I suspect that the mechanism is the same. Regardless, you should't need it as service manuals rarely provide step by step help in rebelting anyhow. For this service, good mechanical aptitude will get you far.

Thanks, BF. Yeah, I realize I'll probably end up changing the belts. Always hoping, of course, to avoid having to do it. But I'm also wondering something. Should the flywheel stop immediately when play is stopped? Or when FF hits the end of the tape?This one doesn't (is that typical, or normal?). And when it hits the end of FF there is even a tiny squeaking sound for a second or two--almost like a miniature version of belt squeal on a car. I'm wondering if that's another sign of the belt slipping. Tinker with hifi stuff a bit here, but not much with tape. Hence, the noobish questions!

Panasonic belts of that era tend not to turn to goo. They just loose their tension and start to slip. I've rebelted a 5150 - it's not the easiest deck but far from the most difficult to work on - this series of Panasonic deck are amongst the most reliable of all vintage Boombox decks. It should sound great after a service.

This is easy unit to work on even for a newbie. 😉


Bad Boy Bill

baddboybill said:

This is easy unit to work on even for a newbie. 😉


Bad Boy Bill

Click to expand...

I do have to admit, it is nice the way the whole cassette unit is easily removed via just four screws and all the wiring has modular connectors. It just looks a bit more complicated getting at the belts and all. Are belts still available by model/part number, or is it only by measuring/guesstimating at what's in there?

Grab yourself one of those EBay bulk belt packs - you're bound to find the right size belts you need - make sure you get a pack of flat belts and square belts.

Remember, when you're selecting the correct size belts, you want belts that have just enough tension to grip - pick a belt that's too tight and you'll introduce drag into the system resulting in excessive wear and a slow playback.

These sizes are usually pretty close 😉


Bad Boy Bill

Franz Bibfeldt,

You already got the best members here on this site to help you out.

Welcome to this beautiful site!

BoomboxLover48 said:

You already got the best members here on this site to help you out.

Click to expand...

And I very much appreciate it! Is that a link to a site BadBoyBill? Russell Industries? I tried to figure out how to find what you posted, but it's a bit of a challenge to navigate their website.

And I very much appreciate it! Is that a link to a site BadBoyBill? Russell Industries? I tried to figure out how to find what you posted, but it's a bit of a challenge to navigate their website.


Yes 👍


Bad Boy Bill