Panasonic K mechanism ejects tape?

milo · #1 10-11-2021, 11:29 AM

Hello all,

I'm currently trying to revive a Panasonic K mechanism where a vhs tape is loaded, is read for a few seconds and then ejects. I'm following the extremely helpful video that Quasipal uploaded to youtube showing common issues and how to repair them.

I have checked the motor coupling and there is a very small crack in the plastic, but the coupling was very tightly held on the motor shaft. I'll be sourcing or printing a replacement of the coupling for good measure.

I also noticed that when initially loading the tape, the P5 arm isn't located next to the roller (circled in the photo), so the tape isn't being pulled up and positioned near the pinch roller (as can be seen in the video). If I were to manually move the P5 arm so it touches the roller before inserting a tape, the tape is unwound and ejects but is a little chewed up on exit.

I've yet to clean the mode switch or check the alignment of the mechanism. (I'm just waiting on some more contact cleaner and grease).

Would anyone know why the P5 arm isn't in the correct position?

hodgey · #2 10-11-2021, 04:00 PM

I don't know why it would sit like that but presumably there is one or more gears that have skipped for the guide to sit like that. It's supposed to sit so the tape goves over it when inserted so it can drag the tape up to the pinch roller. You will have to take out the mechanism, and go through the gears on the bottom to see if they're correctly aligned using the K mechanism service manual. The out of position arm may be what's causing it to eject as well, there are some failsafes in the microcontrollers that will eject the tape if certain conditions are not met, and it's possible the arm also prevents the other parts from fully loading.

RobustReviews · #3 10-12-2021, 05:19 AM

Sounds like a total loss of alignment, it's a complete pain but my personal method if I suspect a deck alignment is to just 'start again' as trying to align individual parts can be more troublesome than just taking everything off and starting from scratch.

I've seen this issue with G/G2 caused by slipped teeth.

milo · #4 10-13-2021, 08:15 AM

Thank you both for the replies. I'll be sure to strip everything down to take a closer look and report back on what the issue was.

milo · #5 10-25-2021, 08:59 AM

Looks like the main lever unit has been damaged where the P5 arm would slot into place. It appears that someone has tried to repair this unit (or have caused the problem by not reassembling correctly) as there are also a few screws and washers missing.

milo · #6 11-08-2021, 03:44 AM

Just to update...replacement of the main lever unit and re-alignment appears to have fixed the issue.

RobustReviews · #7 11-08-2021, 02:47 PM

Quote:

Originally Posted by milo

Just to update...replacement of the main lever unit and re-alignment appears to have fixed the issue.

That's great news.

I'm a Panasonic Stan so it's always good to hear these machines are being repaired. As pure anecdote, they're usually less mechanically troublesome than some other big brands.

I think you're right, looks like a previous wonky repair!