Tandberg 990 MXP Repair. (Flying blind)

Discussion in 'General Electronics Chat' started by SteveHow, Jan 28, 2015.

  1. SteveHow

    Thread Starter Member

    Jul 2, 2012
    Good day to all,

    It's been sometime since I have visited. Some might remember my last attempted repair, the dreaded Roland Digital Piano. Sadly, that got pushed back and abandoned due to my frustration, especially when I slipped with my Logic Probe seemingly taking out a major IC in the process. (You know, when you get that doubt that says "You just made it worse, you idiot") You never really know if infact you had made it worse or it was simply some coincidence. The Piano is packed away, who knows one day given more experience and confidence I may revisit. I should also thank those who helped during that time. Thank you.

    So, today I'm back with a new repair project. (At least its not the size (and weight) of the old dead Digital Piano) This unit will present challengers, mostly because there are no Schematics.

    I picked up this unit from the scrap heap, namely a Tandberg 990 MXP TTC7-08 (Video Conference Camera) Cisco took ownership of Tandberg some years ago. It has reached it's EOL.

    The fault, is no power. Dead, no lights. I had some trouble finding the correct polarity and honestly, I may have blundered right from the start. I don't have the original power supply (12V DC@ 3A) I have the best match I can find at this point, 12V DC@ 2A. After doing a Continuity test, I found that the outer terminal was grounded to the external interfacing connections. Does this tell me positively it's therefore (-) negative ground? If someone could confirm this for me, that would be awesome. I couldn't confirm that fact.

    However what would definitely help is identifying what I believe is the Input Voltage Regulator 3 Pin IC. It looks like a small version of the TO-220. (Sorry, I don't know is official package name)

    I have hunted online but cannot find reference to the 3 pin IC. I'm hoping someone with more experience might be able to ID it for me. I can then find its Data Sheet, confirm DC Input Polarity and hence get me start on a possible repair.

    It is labeled as follows.


    Does anyone recognize this IC please?

    It would be very much appreciated.

    Thank you