Panasonic AJ-Series issues

[ARC Tech-109]

I have a 755 that has this oscillating issue with the tension on the supply reel, it's a lmost like it's trying to overcompensate before it begins to jerk and throw an E64 error. I'm not familiar enough with the Panasonic and keep striking out on a service manual.
I also have a AJ-HD150 with a dead power supply. It pulses like it's trying to start up so I replaced several shorted caps but despite my efforts its still a no-go.
I also aquired a pair of the D230 decks with what I assume are worn heads. If I select DVCAM format run a DVCAM tape it plays well but a native DV format tape will go blocky from the errors before going E-01 low RF. I recall the DV track width was 1/2 that of the Sony DVCAM format so this is where I drew my conclusion. Are these heads replaced as a unit with the motor or as just the upper cylinder?

I'm not very fond of the modern Panasonic "pro" equipment but I do have a need for them so thoughts or suggestions would be appreciated.
Thanks in advance.

(retired) Arc-Tech 109

[ARC Tech-109]

AJ_SD755 issue solved. For future reference it was a weak tension arm spring, the tension arm is only a feedback link being it uses a magnet & hall effect to maintain a working "window" of tension bucking the supply reel motor. Another Panasonic oddity.

Still need info for the AJ-HD 150 power supply or at least a pin-out of the DC rails.

Thanks

[zenith2134]

Thanks for the tip. I have a similar model in storage; cannot recall its model number but it is an AJ- for sure. Matsushita sure liked those Hall effect motor circuits on their Technics turntables. When they were new they must have been state of the art, but as we now see, simple parts like springs and 'lytics cause them to go off speed.

I had an SL-D turntable model with erratic bursts of high speed operation, which turned out to be the platter rim speed sensor inside the plinth being ~half inch too far away.

Apparently it had gotten knocked askew at some point. It played 33.3 all day after carefully epoxing it in place.

[djski]

Originally Posted by ARC Tech-109

I have a 755 that has this oscillating issue with the tension on the supply reel, it's a lmost like it's trying to overcompensate before it begins to jerk and throw an E64 error. I'm not familiar enough with the Panasonic and keep striking out on a service manual.
I also have a AJ-HD150 with a dead power supply. It pulses like it's trying to start up so I replaced several shorted caps but despite my efforts its still a no-go.
I also aquired a pair of the D230 decks with what I assume are worn heads. If I select DVCAM format run a DVCAM tape it plays well but a native DV format tape will go blocky from the errors before going E-01 low RF. I recall the DV track width was 1/2 that of the Sony DVCAM format so this is where I drew my conclusion. Are these heads replaced as a unit with the motor or as just the upper cylinder?

I'm not very fond of the modern Panasonic "pro" equipment but I do have a need for them so thoughts or suggestions would be appreciated.
Thanks in advance.

(retired) Arc-Tech 109

Over my career, I have come across few electrolytics that actually shorted. They usually open from age and heat.. A surge may have shorted some caps on your HD150. Might want to look for an open electrolytic capacitor on the primary side of the transformer. They are usually small in value, around 1uf with a voltage rating around 160v.
How many drum running hours have accrued on your 230's? If several thousand hours have accrued, the heads likely are worn out. They usually can go 1500 hours with minimal care. I have done head replacements on the D230 long ago.. The upper and lower drum come as an assembly. You can't get just the upper drum. Before comdeming the drum assy. make sure your tape path is properly aligned. With narrower tracks, the DV material will be far less forgiving and artifact much easier.
Another possibility(WHICH IS MY GUESS) is faulty surface mount capacitors in the head amp circuit. I have changed many hundreds of these caps on D230'S and they can fail on any board. That's why Panasonic offered board specific cap kits which were available long ago and you replaced them all on the affected board. I have been out of the industry a while now and do not know if any parts are still available anymore as Panasonic usually discontinued parts after seven years..

[ARC Tech-109]

I did look at the heads themselves under a low power (30x) stereo microscope and they are clearly worn down to the nubs, I'm not going to invest much into their replacements as the decks have well over 5000 hrs on them. I have a low hours AJ-D150 with a water damaged power supply, service manual arrived today and that will be used as the replacement for the 230's. The 755... it has its moments but works well enough but none rise to the caliber of my A500/1 DigiBeta

Thanks for the replies, if I can do anything please let me know

[djski]

Keep in mind all the DVC PRO units had widespread cap issues.

Comparing those decks to a Digi Beta is like comparing a chevy to a Cadillac.

They all had their moments but are dinasaurs now. All worth very little.

[ARC Tech-109]

I'm only keeping the DVCPRO going for compatibility sake, I did a lot of camera work and have an extensive library of training and service videos that I'm too lazy to grab and archive. Maybe when I retire ��