Tascam Porta Two – pinch roller not making contact

T

The Swill Man

New member
hi folks, hoping someone can help with this issue. i've got a Tascam Porta Two here that i'm fixing up. i replaced all four belts in the tape mechanism (all were stretched out) and now i'm encountering a strange problem. when i try to play a tape, the heads rise up and make contact, but the pinch roller doesn't go high enough. and then playback aborts a second later. the machine could probably use a new pinch roller anyway, but i don't get what's going on here. if i manually nudge the pinch roller arm upwards, the roller makes contact, the tape moves, and the meters go, because the heads are already in contact. but for some reason, hitting Play on its own doesn't move the pinch roller upwards quite enough. i can't see anything obviously broken or bent, etc... any hints? i hope my description was detailed enough. thanks.
 
When you replace the belts, the one that raises and lowers the headblock assembly is also responsible for ensuring positive engagement from the pinch roller. There is typically either A. a procedure for properly aligning the headblock assembly position relative to the position of the pulley that drives the belt that moves the assembly up and down so that the headblock (and pinch roller) are in the correct position at the beginning and end of the travel, or B. a trim pot to adjust and align the position of the headblock assembly in PLAY mode to ensure everything is working right.

When you press STOP or when the transport gives up and quits after you try to PLAY, look at what the headblock assembly does...does it drop down and stop, or does it drop down and pop back up a little? If the latter then I’m confident your issue is simply an adjustment, either mechanical or electronic.

I can’t help any further as I do not have a service manual for the Porta 02, but maybe somebody here does and can help.
 
sweetbeats said:
does it drop down and stop, or does it drop down and pop back up a little?
Click to expand...
the former. i do have the service manual here. it's a bit skimpy IMO and the only relevant information i found, on my first read-thru, is the tension checking procedure for the pinch roller, which i have never done, and i'm not sure is even relevant. but it might be.

IMG_3315.png
 
Last edited:
That’s all it says? Doesn’t say anything about what to do if the tension is outside the specified range?
 
yes!! that's what has me scratching my head. that's all it seems to say on the subject. the manual is bilingual, and i ran the Japanese description thru Google Translate, but it's identical. (hey, worth a try!)

what would be the typical procedure in this case for adjusting pinch roller tension? i have never had to do it on any sort of tape deck.
 
Last edited:
reading the manual more closely, i just had another thought. in many parts of the test procedure it says to replace this or that spring if something is out of alignment. this Porta Two had a decent amount of internal oxidation on the metal parts. two connectors had disintegrated and i had to strip the wires and replace them. i am wondering now if the springs have suffered as well and possibly become too weak.
 
You must log in or register to reply here.
Back
Top