Reviving Test Equipment After A Long Storage Period
in [Repair]
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From: John Robertson on 8 Feb 2010 16:54 Too_Many_Tools wrote: > I have a number of pieces of test equipment (HP, Tek, Fluke...digital/ > analog/RF) that have been sitting in storage for a decade. > > Time to apply the power and see if they work. > > What is the recommended procedure to bring test equipment that has > been stored for a long period? > > Also is there a MIL document that relates to this subject? > > Thanks for what info you can offer. > > TMT Depends on the equipment. In our shop we constantly use old test gear from the 70s (Fluke 9010, scopes) and they rarely need attention. If you are worried about electrolytics exploding then you could run the equipment on a Variac and dial it up gradually - note that this is not going to work with switching supply machines. On the other hand gear that uses tape or hard drives can have failures related more to moving parts seizing up. Tape drive equipment will likely have flattened capstans and melted drive belts, ancient hard drives may have turned into 'shake&bake' where you have to give them a snap to start the platters turning (don't do this if it DOES work!) - the bake part is to leave it on from then on until you can archive the data safely! There are electronic replacements for old hard drives SCSI, MFM, and IDE you just have to do a little hunting and sometimes pleading. I picked up a SCSI adapter that I am going to see if my IDE to SmartCard device can interface with so I can replace the drive completely on my Fluke 9100s. Might get to this project this summer... With stuff only a decade in storage? I'd turn it on and see what happens - most likely it will work if there is no corrosion. John :-#)# -- (Please post followups or tech inquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."
From: Jon Elson on 19 Feb 2010 18:59
Too_Many_Tools wrote: > I have a number of pieces of test equipment (HP, Tek, Fluke...digital/ > analog/RF) that have been sitting in storage for a decade. > > Time to apply the power and see if they work. > > What is the recommended procedure to bring test equipment that has > been stored for a long period? > > Also is there a MIL document that relates to this subject? > > Thanks for what info you can offer. > The big killer is electrolytic capacitors. Aluminum electrolytics often survive, but may take a while to reform their dielectric, drawing some current until that happens. Tantalum wet-slug caps are AWFUL, and have a TERRIBLE failure history in exactly this situation. What's worse, in some "mainframe" computer sort of systems with large power supplies, is they will burn holes in the circuit boards, leading to almost irreparable damage. I know slowly charging the aluminum electrolytics by bringing the voltage up slowly with a Variac is a time-honored method in the days before switching power supplies. Something I've tried since then is to blip the power on and back off immediately once, let the unit sit for ten minutes and then power up and see if it runs. I think the military has been playing ostrich with this since the Vietnam war, but it keeps those techs busy replacing caps at the repair depots. Jon |