What component is this?

Discussion in 'General Electronics Chat' started by RobeeJ, Jul 10, 2013.

  1. RobeeJ

    Thread Starter New Member

    Mar 19, 2013
    24
    1
    Can anyone help me identify what this component is? It's from a faulty HP E2373A multimeter I'm trying to fix.

    It's marked as RA1 and appears to have three pins.

    [​IMG]

    I don't think this specific component is faulty (symptom is when measuring resistance in the low ranges, the measurement increases slowly over time, so if you short the probes it says 0 ohms, and slowly continues to climb) I'm just curious to know what it is.

    Thanks for any suggestions!
     
  2. WBahn

    Moderator

    Mar 31, 2012
    17,715
    4,788
    The component designator is "RA1". RA is often used for resistor arrays. How many pins is this part? It looks like it might be three, which would be odd if it were an array since those tend to have an even number of pins. It might also be a T-filter.
     
    RobeeJ likes this.
  3. RobeeJ

    Thread Starter New Member

    Mar 19, 2013
    24
    1
    Thanks for the reply.

    It is three pins. The markings are H- and 112A, which is even more confusing.

    I guess I could de-solder it if I'm really curious and check the resistance. I'd rather not though. :)
     
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    A good brand multimeter like your H.P. will often use calibrated specialty resistors or resistor dividers.

    I think WBahn nailed it being a precision resistor array, probably a 3 pin two-resistor voltage divider.
     
    RobeeJ likes this.
  5. RobeeJ

    Thread Starter New Member

    Mar 19, 2013
    24
    1
    That explains it, thanks guys!

    Still no nearer to working out what is causing the rising ohmeter reading, changed all the electrolytics, think I better change some of the other caps next...

    I figure it is most likely a cap causing it, not much else in there. :)
     
  6. Dr.killjoy

    Well-Known Member

    Apr 28, 2013
    1,190
    156
    I would suggest asking or find the schematic and work form there since most of the time they list exactly what part was used instead of guessing ..:)
     
  7. RobeeJ

    Thread Starter New Member

    Mar 19, 2013
    24
    1
    Many an hour has been spent googling for the schematic or a service manual or anything useful. :/

    The manual is on Agilent's website, but the closest that gets to a schematic is what the pot adjustments are for.

    Hence why I'm down to guessing and asking you pips. :)
     
Loading...