Weird stuff -- update -- (was Electronic Kenmore refrigerator not working, what does this sign mean)

[DerbyDad03]

re: "At one time there was a special connector sold that you soldered to the tin plate, and had gold plated contacts to mate with the ribbon cables."

Trust me, I know all about the many corners they cut! ;-)

However, how would this particular connector issue be impacted by the installation of the case? The case had no connectors, it was just a metal shell.

P.S. Before installing the TRS-80's, we opened up every keyboard and ran a wire from the circuit board ground to the plastic case. Before we did that, weird things would happen when the user touched the keyboard.

The worst was seeing the disk drive light turn on and knowing that the program and/or data disk was now corrupt. The least was hearing the daisy wheel printer print out a single character.

We had some users that were so paranoid about their data that they wired a grounding bracelet to the sprinkler system and would hook themselves up before they touched the system.

[J. Clarke]

Just a guess but tightening the crews could distort the case enough to put stress on the drives, altering their alignment thus they (especially with the old stepper-motor drives) no longer have proper track alignment. Solution would be to leave the drive mounting screws on one side a little loose so they support the drive but don't put any load on it--a little Loctite would keep them from working loose in service.

[HeyBub]

The problem hasn't gone away.

We've been farkin' with a CD duplicator for a month. It would randomly fail to eject a CD. Replacement of the CD drive with a new one didn't help. We finally got it to work flawlessly but when we tightened the screws holding the drive in place, back to the same symptom.

Turns out, tightening the screws distorted the drive (made of old beer-can metal).

Loosening the screws somewhat returned the duplicator to perfect functioning.

[Bob Villa]

Or the screw went too deep and needed a washer (or a shorter screw). May have bound a pivot point or track/rail.

[DerbyDad03]

Many times we just left half the screws out altogether!

[aemeijers]

Snort. I used to see that issue in brand new PCs just out of the crate- hard drive had 2 screws on one side, but only one on the other. Thought it was a production boo-boo, so started checking all the other ones as I was installing the memory upgrades and tape drives (yeah, this was a few years ago), and they were all like that. Only using 3 screws was a real common trick on early CD drives, before they got the hang of designing them cheap but stiff.

[PeterD]

No it souldn't except when the unit has been moved and possibly oil is in the 'wrong' places and must drain back. THen it can take 20 minutes. But to expect a person to determine this condition is not realistic, so I recommend 20 minutes.

(Even your estimate of 5 minutes is usually much more than is needed, I've seen them bleed down in under two minutes.)

[Michael A. Terrell]

Some cases put pressure on one side of the ribbon connector. The modification extended it outside of the case. I repaired a lot of early computers, too.

[The Daring Dufas]

Back in the late 70's I worked for Tandy repair and most of the trouble with their equipment was caused by cold solder joints. The connections made with plated through holes on the circuit board were always suspect.

TDD

[Martin H. Eastburn]

Vapor lock. Likely a little light on freon and the pump shutting off gets a high head pressure and can't push up to clear it.

Likely in the off position, it will leak pass a gasket and it will start.

That is my suspect. Might be that way only when hot. e.g. just running.

Might work in the shop all winter if cold out there - lightly running and cold coils. Warm house shuts it down.

That is what I figure.

Mart> Things are getting weirder and weirder. My original post is at the bottom. >