Tascam 414 MkII with Dead Channel 4

Discussion in 'TASCAM DIY Repairs and Mods' started by Mart, Dec 27, 2020.

  1. Mart

    Mart New Member

    Dec 2020
    I recently dugout my Tascam 414 MkII from my closet that I got years ago and never properly learned to use. Now that I want to learn to use it I discover that track 4 won't pass any signal, both pre-recorded on tape or live from the mic/line/guitar in. All the other channels seem work fine, but when attempting to record or even just pass signal into the headphones/monitor outs track 4 is dead silent. Recorded something on track 1 to flip the cassette and see if it would play in reverse on track 4 and again, dead silent. When turning up effect 1 while playing the cassette I noticed a 'white noise' present in all but track 4 when the knob was turned up all the way. It also cant have tracks bounced down to it. I have absolutely no knowledge of how to go about fixing this but do have a soldering iron and I would really appreciate some advice on how to go about fixing this. If this is something out of my realm of abilities would I appreciate being pointed to someone who would be able to fix it.
  2. SkywaveTDR

    SkywaveTDR Well-Known Member

    Feb 2014
    Chicago area
    Teac, Tascam, Sony
    It is not beyond your ability if you were a electronics technician but if that was the case then you would not be posting this question. The smallness of these units and the way they are designed makes it even more difficult for people to fix them out in the field. Sometimes you need extension cables which have to be made up as the manufacture probably threw them out. Usually the line in is what is damaged due to excessive inputs and I have fixed that. You may have after all these years a Marcon cap (Electrolytic) in the circuit that is open or shorted. They have been found to not be the same grade as Nichicon or new present day caps. In some cases the fixing of one section such as the line in will help fix the tape play section . If the part that is defective in the line in section is in common with the tape section then when one is fixed both come back. Letting a device built to minimum standards as these were sit for long times and then go to be used 20 years later just makes for an automatic repair- they were never designed to be treated this way. The parts in them such as Electrolytics were not the same as those in the older Teac unit that can and have lasted 50 years. These were mostly Nichicon caps.