Over the years, I've seen perhaps 10,000 pieces of electronic gear. In that time I can remember 4 "out of factory" failures: In no particular order:
The unsoldered part in an HP LASER Interferometer I posted previously. In an HP "Communications Sweep Oscillator" covering 3.7 - 4.2 and 5.9-6.5 GHz, there was a screw loose (really!) in the output amp MMIC. A microscopic inspection showed it had never been tightened at the factory. The MMIC was trashed. In a Data General semiconductor memory board for a Nova 3, 30-50 IC leads were never wave soldered. In a Test Station for a Raytheon AMRAAM missile, there were unsoldered joints on a switch. In all cases, I think the units passed inspection and were delivered to customers. ears ago, when I was building space payloads, I was told by a guy at MIT's Lincoln Labs: "You cannot inspect in quality." He was right, IMO. Best, -John ======================== [snip] > On the 'bad out of factory' issue, I never saw in HP or Agilent equipment, > but one Sony TV once had 5 pins on the tuner never soldered - the factory > whistle must have sounded after pin 5 and the thing was tested and shipped > the next day. This was a lesser line out of Mexico - two XBRs have been > running for 10+ yrs without a glitch. > > Jose > > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Geoff Blake > Sent: Sunday, September 11, 2011 1:33 AM > To: time-nuts@febo.com > Subject: Re: [time-nuts] HP quality > >>> That is not a unique incident. >>> >>> I'm interested in LASER Interferometry. Attached is a pic I took of an >>> HP >>> 5529A LASER head. >>> >>> (Aside: If anybody is interested, there is a Yahoo Group for LASER >>> Interferometer fans) >>> >>> Note the two leads to CR5 near the top, center of the pic. They go to a >>> feedback photocell and obviously have never been trimmed or soldered. >>> >>> The unit ran fine that for several months before suddenly failing. >>> Soldering the leads fixed the LASER head. >> >> It was not always this way. Today I stumbled on a 1965 HP 738BR >> Voltmeter Calibrator at my favorite surplus electronics store. I >> offered $20.00 and it was accepted. >> >> This unit is based on vacuum tubes! I got it home, plugged it in, and >> it is still in spec on the DC range. The AC part is not working - I >> suspect the small incandescent lamp that stabilizes the oscillator. >> >> I may end up junking the vacuum tube half. The other part of the >> instrument, in a separate compartment, has a precision 40 step >> attenuator with a 10^6 / 1 range (300 Volts to 300 uVolts) which I will >> certainly keep. >> >> Best regards, > > No please don't junk the valve part, it would be be waste of a lovely > instrument. > > However that's not the topic. > > I first met a HP 3582 LF SA when it came into the cal lab from a > remote site, just out of warranty. Apart from being out of cal, the > was a brief comment, "intermittent channel 1". We had not seen one > before and being the "guv" I got to play first. > > Yes there was an intermittent fault and it seemed vibration sensitive. > After I had figured how to drive it (what's a FFT analyser - what's a > FFT? but I was young then.) I could confirm the fault and I had even > found the diagnostics in the manual. > > Running diagnostic 1 I determined that the fault was in IC1 or IC3 and > using diagnostic 2 I narrowed it down to IC1 or IC2, so suspecting a > loose IC1 I put a rather large thumb and pressed - the fault > disappeared Remove thumb and it was back! > > In for a penny, in for a pound, I pulled the chip and yes, even I > could spot the doubled up pin, so I gently straightened it and that > was the cure. Later I was told that the fault was there since > delivery, but they could not afford to spare it at the the time. > > (Please note the (IC) names have have been changed to protect my memory.) > > Geoff G8GNZ > > -- > ############################################### > Geoff Blake, G8GNZ JO01fq: Chelmsford, Essex, UK > <ge...@palaemon.co.uk> or <melecert...@gmail.com> > Using Linux: Ubuntu 11.04 on Intel or Debian on UltraSparc > and even on the NAS. Avoiding Micro$oft like the plague. > ############################################### > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.