PDA

View Full Version : Shelf Rot



curtis
June 2nd, 2009, 05:06 AM
I'm pretty sure others have experienced this before.

You get in a cherry piece of equipment. It goes on your workbench and checks out PERFECTLY!

Okay, you're kinda busy and you've got other equipment coming in, so you put it on a display shelf and forget about it.

Some time later, to be measured in months, you have a free moment and decide to play with that beautiful XXX you got in. It goes back on the bench and lo and behold that !@#$%%^*& thing is completely dead!

I've come up with a term for this phenomena, shelf rot.

How many others have experienced this?

I have a Zenith MiniSport HD that a few months ago was in absolutely perfect working condition. This past weekend I decided I was going to part with it so on the workbench it went. Let the battery charge up overnight and checked it the next morning. Dead as a door knob. Checked the battery in another MiniSport and works perfectly. Yep, the power board has bought the farm sitting on the shelf.

Curtis

barythrin
June 2nd, 2009, 08:32 AM
lol, not the proudest thing I'd like to admit to but for honesty and to benefit other collectors yes I have that happen too.

I at least think it's a big part of storing the units in good (AC/humidifier, protection from extreme temperature changes, etc) conditions but I don't get through all my systems. Given like a few folks have mentioned, depending on where you live and the size of the collection this gets more difficult. I'm also in Texas, it doesn't get as cold here as it will up where you are but I have to keep the majority of my collection either in the garage (at least I have it insulated) or up stairs. I imagine this isn't the best environment but it's all I can do besides try and power them on with a regular schedule.

Problem is even if I dedicated a week to each machine a few of us would still be 2+ years before we get through the collection.

My guess is the two easiest culprits of shelf rot are the capacitors drying and/or leaking and batteries leaking and damaging the boards.

curtis
June 2nd, 2009, 08:47 AM
Yeah, batteries are the usual suspects, but in my case, all the batteries, including backup coin batteries were removed.

This particular line of laptops were prone to failures all through the power system. The usual problem is in the back light portion of the display. Zenith elected to go marginal on several components and they do love to fail.

tezza
June 2nd, 2009, 09:49 AM
This happened to me with my IBM PC and Osborne 1.

It's damm annoying!

Luckily I managed to get them going again.

Tez

Yzzerdd
June 2nd, 2009, 10:38 AM
I had this happen to my IBM PC Portable. I used it in a presentation in school, brought it home, and played Flight Simulator on it. I then set it down into the closet, because I needed to make room for another system to be set up. About a month or two later, I decided...wait...3 months. Anyhow, I decided to bring the thing back to life, as between my girlfriend, looking for a job, and shipping stuff, I hadn't gotten to use my computers really at all, except my new one. Anyhow, everything is plugged in, I sit down in the command chair, flip the switch, and nothing.

I did the usual checks, make sure the socket has power, change cords, etc, but it's deader than a door nail. One of these days I'll get around to testing it, I just don't know where to start, let alone how to test the PSU components.

--Ryan

cosam
June 2nd, 2009, 11:29 AM
Yep, I'm sure more than a few readers can relate to this! Regularly powering up should help, but stuff can and does "just go bad" whatever you do. The most annoying thing is when applying power is the very action that causes failure. Sometimes the sudden rush of current through old component is enough to make them go pop. At least you get to find out where the weak links are though!

barythrin
June 2nd, 2009, 12:11 PM
That's one of the things that's scared me out of powering up two of my Kim-1's and my IMSAI. I'm so afraid that it'll go wrong, I know I'm supposed to connect things through a variac (still pending buying one) and slowly let it go up in voltage but it seems so likely I'll end up causing something to go wrong despite them working when I bought them. If I got them up I'd start powering things on once and a while or at least add specific systems to my maintenance schedule though.

Part of the problem at my current stage is getting areas for all of them to be set up again. As the collection grows my setup space keeps running out and it goes from a nice showable set up to the mess in the garage/boxes.

Lorne
June 2nd, 2009, 03:34 PM
OK, you've all got me going now.

Mine are all indoors - nothing in the garage, even though it is air conditioned.

I've spent so much of my time (and others too with helping me) get these things working (mostly Ebay purchases!), that now I'm going to have to start them up at least every couple of weeks.

Maybe that'll be painfull enough, that I'll quit buying more of them.

tezza
June 2nd, 2009, 04:30 PM
Yea, I once had the laudable aim of switching all mine on every two weeks or so. Well...err...that was the aim but it didn't pan out.

Unless they ARE all set up ready to go and you can just flick switches, it's not that easy.

I just live in hope.

Tez

NeXT
June 2nd, 2009, 07:22 PM
I have had this happen with a PS/2 36 SX (now gives a 604 media sense error for no reason) and a Silicon Graphics Personal IRIS 4D/20. The PS/2 is still sitting under my desk to some day be looked at but the 4D/20 took three years to repair (had to replace the whole main board).