Porta One Recording Issue

Discussion in 'TASCAM Analog Forum' started by atom.jack, Aug 5, 2020.

  1. atom.jack

    atom.jack New Member

    Aug 2020
    Porta One, Two, and 07
    Hi, new member here. A couple weeks ago I bought a Tascam Porta One in "great working condition" from a gentlemen off Reverb. When it arrived, the unit couldn't play tapes for more than a second without engaging the auto stop. I decided to get a partial refund and see if I could fix the unit myself. Going through old forum posts I found the issue was a crack in the plastic base the tape heads are attached to. The spring that pushes the heads to the tape holds too much tension for the plastic to handle over time, and I guess this a common issue across this model. Upon removing the the heads from the base, I found the erase head cracked and on the verge of falling apart. I went on offerup and picked up a broken Porta Two to scavenge a head and other parts from. To bring the spring back into tension without relying on the plastic base, I decided to try out this method I found here.


    This seemed to work, my unit can now play tapes just fine. However no good on the record function. I followed the instructions on the user manual; type II cassette loaded in, I get an input from line 1, record armed and the LED stays red, yet nothing when I playback the tape. I have a pdf of the service manual handy, but I'm not sure where to start when tackling this issue. Keep note I have an extra play/rec head from a Porta Two, but I have yet to see if replacing it will fix it. Some wire points did come loose when rebuilding the transport, but I have double checked everything has been resoldered and secured. This is my first time repairing this kind of unit, and this is going to be my first time recording to tape. I'm not sure what went wrong here. Also no audio signal from line input 2 and 4, but right now I'm only worried about getting 1 track recorded to tape. Can anyone help?
  2. SkywaveTDR

    SkywaveTDR Well-Known Member

    Feb 2014
    Chicago area
    Teac, Tascam, Sony
    Well I look at these different than a user would being my back ground. I would take a scope probe over to the erase head and when in record mode erase sine wave should be detected as this is the full output of the oscillator- If there is none then either there is lack of DC to it or a switch is bad or the Bias block may have bit the dust. The final reason would be found out when determining where the problem was. Being these are portable and full of non-aerospace solder joints the possibility is that there can be a broken solder joint in there somewhere.