Re: Re: Omega Race repair

Re: VECTOR: Re: VECTOR: Omega Race repairI have the Dick Smith meter, its a nice bit of kit
  ----- Original Message -----
  From: John Robertson
  To: vectorlist@vectorlist.org
  Sent: Thursday, October 12, 2006 3:44 PM
  Subject: Re: VECTOR: Re: VECTOR: Omega Race repair

  Oh, and I'll give $5US off the kits for Vectorlist members - this week only! In exchange for the somewhat blatant ad.
  http://flippers.com/esrktord-form.html Mention you saw the note here and I'll Paypal you back the $5US discount.

  John :-#)#

  At 7:34 AM -0700 10/12/06, John Robertson wrote:
    Hmm, I wonder is our Dick Smith ESR kit might work here? The Dick Smith (designed by Bob Parker in AU) ESR Kit K-7214 meter goes down to 0.01 ohms...with a good set of probes that is! I recommend you check out Probetronix.com for those. They give a slight discount for our customers ($1US off) for the tweezer probes if you show them the invoice...

    John :-#)#

    At 3:39 AM -0500 10/12/06, Rodger Boots wrote:
      Zonn wrote:

        On Thu, 12 Oct 2006 07:23:32 +0400, peter jones <highwayman2000@mail.ru> wrote:

          -----Original Message-----
          From: "simon" <simonjhanlon@btopenworld.com>
          To: <vectorlist@vectorlist.org>
          Date: Wed, 11 Oct 2006 23:07:04 +0100
          Subject: VECTOR: Omega Race repair

            Today I thought it was time I fixed my Omega Race, I have a few spare boards for it, most with some acid damaged. I found one that was fairly clean and replaced the 2 ram sockets near the battery. On power up the + and - 15v regulators were getting too hot to touch, I checked between the 2 and had a reading of 35 ohms between the-15 and 15v lines. I suspected one of the Op amps or a DAC was to blame. After pulling 3 of the 4 Op amps I found the bad one,
                 

          couldnt you find the bad one by burning your finger on it?
          that works pretty good with dram a lot of the time.
             

        That's a good point!

        I'll bet one of those infra-red temperature pointer thingies would work well in
        spotting parts that are overheating. You know, after you've burned away the
        nerve endings on your 10th finger...

>From the ad at the top of Google:

        http://www.testequipmentdepot.com/newequipment/irthermometers.htm?gclid=CI3fptHX8ocCFQU8YQodskxUjQ

        -Zonn

      Or just finally get a much better ohmmeter.
      At my Real Job I have an HP 34401 multimeter. A use it for finding which one of 19 paralleled capacitors is shorted. I put it in the 20 ohm range, select 6-digit mode (measuring 1/10 of a milliohm), and it has a min/max mode. With all that going all you have to do is probe each part---the last one that makes it beep (because it was the lowest reading) is the shorted part. Too bad it costs several hundred dollars for one of those.

      A much cheaper way would be to clip your meter across the two power supplies and spray one part at a time with freeze mist. Whichever part gives you the largest resistance change is the shorted part. (That's too simple, can't possibly work---or can it?)

      Or, if you can't even afford a meter there is another simple way. Frost up all the parts in question and turn it on. The first one to defrost is the bad one.

-- 
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
  Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
                   www.flippers.com
  "Old pinballers never die, they just flip out"
------------------------------------------------------------------------------
  No virus found in this incoming message.
  Checked by AVG Free Edition.
  Version: 7.1.408 / Virus Database: 268.13.2/472 - Release Date: 10/11/2006
---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com