Re: [time-nuts] Agilent 53132A Needs Help
Hello, Monday, January 26, 2009, 14:14:54, David wrote: D> I think I've seen seven Agilent 54132A counters and three of units flagged a D> ROM fault after Power On Self Test. They had all been well looked after, D> sitting in racks in a very high end environment, I suspect they were D> switched on continuously all year. The last statement may be a clue of D> course. When I worked with older CNC equipment (Fanuc, Bosch), after any occurence of checksum error we do a total refresh of all EPROMs in a unit. And the same was scheduled to each other routine yearly maintenance (i.e. we reprogrammed all EPROMs each 2 years just to be completely sure). Needless to say, that we had images of any and all EPROM chip archived. D> I did have a very brief play with the 'faulty' ones and things seemed to D> work after the fault message was acknowledged, I could not see any symptoms D> other than the self test error message. A nice counter but I'm D> getting ever more nervous about the ability of current test D> equipment to survive 5 to 10 years. I always try to keep known good images of all programmable chips from equipment I own, if it is possible.. It is already saved me from troubles with my Marconi 2955, where calibration EEPROM (Xicor X2816) failed one day... At the same time, I'm little nervous, too, about more modern equipment that have both firmware and calibration data on a single SMT flash chip. Or, that is even worse, on a some 1.8" HDD... A friend of mine already have Rohde & Schwarz cell phone tester with failed HDD, so internal harddrives is also on my "must be backed up" list now. OS/Firmware usually may be copied from similar unit, but calibration data is something unique and may be very expensive thing to recover. I already saved few various units with leaked EPROMs or parallel EEPROMs using method that I described earlier in this list, but I'm not so sure that it will work equally well with flash chips, so looks like it is better to have a full image on disk. -- Best regards, Yuri mailto:y...@ostry.ru ___ 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.
Re: [time-nuts] Agilent 53132A Needs Help
> Date: Thu, 22 Jan 2009 23:00:04 -0500 > From: tomk...@nist.gov > Subject: Re: [time-nuts] Agilent 53132A Needs Help > To: "Yuri Ostry" , "Discussion of precise time and > frequency measurement" > Message-ID: <20090122230004.10395e4xbu1m3...@webmail.nist.gov> > Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes"; > format="flowed" > > Hi Yuri; > I am late to this thread, but if you have not tried this, reseating > the 4 or 2 eproms which are socketed near the rear may solve the > problem. I am currently having the same problem with one of mine and > in the past this have solved the problem on other units. > Good Luck; > Thomas Knox > NIST > 4475 Whitney Place > Boulder Colorado 80305 > 1-303-554-0307 > tomk...@nist.gov > I think I've seen seven Agilent 54132A counters and three of units flagged a ROM fault after Power On Self Test. They had all been well looked after, sitting in racks in a very high end environment, I suspect they were switched on continuously all year. The last statement may be a clue of course. I did have a very brief play with the 'faulty' ones and things seemed to work after the fault message was acknowledged, I could not see any symptoms other than the self test error message. A nice counter but I'm getting ever more nervous about the ability of current test equipment to survive 5 to 10 years. David ___ 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.
Re: [time-nuts] Agilent 53132A Needs Help
Hi Yuri; I am late to this thread, but if you have not tried this, reseating the 4 or 2 eproms which are socketed near the rear may solve the problem. I am currently having the same problem with one of mine and in the past this have solved the problem on other units. Good Luck; Thomas Knox NIST 4475 Whitney Place Boulder Colorado 80305 1-303-554-0307 tomk...@nist.gov Quoting "Yuri Ostry" : > Hello, > > Tuesday, January 20, 2009, 17:26:00, Richard M. Hambly wrote: > > R> One of my 53132As, an Agilent unit, s/n KR01202209 fail the power-on self > R> test with a FAIL:ROM error message. > > Cannot say anything about your particular counter, but very often such > error is due to 'leaked' EPROM chip, that change value of some memory > cells over time. Last years I seen such problems 5 or 6 times with 15+ > years old equipment, and in most times original EPROM image still can > be read out if you have a EPROM programmer that allow to set arbitrary > Vcc for a chip in programming socket. > > Some background: Erased EPROM cell (actually small piece of > metallization between two layers of silicon oxide, acting both as a > capacitor and as a gate of MOSFET transistor on underlying layers) > reads as logical "one". When it is charged during programming, it > start read as "zero". > > If some cell have small defects in insulating oxide, or just got a hit > of some high energy particle, part of charge can be lost and > "programmed" bit that should read as "zero" starting to read as "one" > under normal conditions (nominal Vcc). > > There is a chance (very good chance, according to my own experience) > that you can find such "partially discharged" bits by lowering > (gradually) Vcc and saving read images to disk for further comparsion. > > Usually I start from 5.0V, make 10-20 reads, saving each one to > separate file in a 5V0 directory, then switch to 4.9V, and do the > same, saving to 4V9 directory, and so on... Usually it is enough to go > below to 4V0... > > When you analyze saved images later, first compare all files in each > directory to each other, you can find some bits that reads unstable at > given voltage. Then compare images between nearby voltages and if > there is any changes, it may be your "lost" zero bits. > > If you go too low, some EPROMS that was written before and then erased > to program current image may show you some of former programmed bits > as zeros - you need to be careful. There was some "erased" EPROM chips > that read as blank under 5V but read out their previous content (and > CRC perfectly match) when read out at Vcc little below 3.8V (not all > brands of EPROM operational at that voltage, though)... > > If there is a CRC on a EPROM label, it may be very useful in > determining that your recovered image is really good. Some devices do > CRC check on startup and you can feel yourself safe enough if checksum > error is gone. > > Always keep your original EPROM chip intact and do not expose it to a > UV or sunlight (if there is no label that cover their window) until > you are completely sure that you have correct image on hand. Use spare > EPROM of same type for experiments. > > > BTW: Looks like it is a good idea to have images of EPROMS and > calibration EEPROMs (if any) for all equipment in a safe place. > > -- > Best regards, > Yuri, UA3ATQ/KI7XJmailto:y...@ostry.ru > > > ___ > 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.
Re: [time-nuts] Agilent 53132A Needs Help
Hello, Tuesday, January 20, 2009, 17:26:00, Richard M. Hambly wrote: R> One of my 53132As, an Agilent unit, s/n KR01202209 fail the power-on self R> test with a FAIL:ROM error message. Cannot say anything about your particular counter, but very often such error is due to 'leaked' EPROM chip, that change value of some memory cells over time. Last years I seen such problems 5 or 6 times with 15+ years old equipment, and in most times original EPROM image still can be read out if you have a EPROM programmer that allow to set arbitrary Vcc for a chip in programming socket. Some background: Erased EPROM cell (actually small piece of metallization between two layers of silicon oxide, acting both as a capacitor and as a gate of MOSFET transistor on underlying layers) reads as logical "one". When it is charged during programming, it start read as "zero". If some cell have small defects in insulating oxide, or just got a hit of some high energy particle, part of charge can be lost and "programmed" bit that should read as "zero" starting to read as "one" under normal conditions (nominal Vcc). There is a chance (very good chance, according to my own experience) that you can find such "partially discharged" bits by lowering (gradually) Vcc and saving read images to disk for further comparsion. Usually I start from 5.0V, make 10-20 reads, saving each one to separate file in a 5V0 directory, then switch to 4.9V, and do the same, saving to 4V9 directory, and so on... Usually it is enough to go below to 4V0... When you analyze saved images later, first compare all files in each directory to each other, you can find some bits that reads unstable at given voltage. Then compare images between nearby voltages and if there is any changes, it may be your "lost" zero bits. If you go too low, some EPROMS that was written before and then erased to program current image may show you some of former programmed bits as zeros - you need to be careful. There was some "erased" EPROM chips that read as blank under 5V but read out their previous content (and CRC perfectly match) when read out at Vcc little below 3.8V (not all brands of EPROM operational at that voltage, though)... If there is a CRC on a EPROM label, it may be very useful in determining that your recovered image is really good. Some devices do CRC check on startup and you can feel yourself safe enough if checksum error is gone. Always keep your original EPROM chip intact and do not expose it to a UV or sunlight (if there is no label that cover their window) until you are completely sure that you have correct image on hand. Use spare EPROM of same type for experiments. BTW: Looks like it is a good idea to have images of EPROMS and calibration EEPROMs (if any) for all equipment in a safe place. -- Best regards, Yuri, UA3ATQ/KI7XJmailto:y...@ostry.ru ___ 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.
Re: [time-nuts] Agilent 53132A Needs Help
I'd be inclined to take the error message at face value; you have some corruption in EPROM or flash memory that isn't in an area that gets used during the measurements you're making. Contacting an Agilent rep would make sense, as the 53132A is new enough that there might be an easy way to upgrade/reflash the firmware. -- john, KE5FX > > One of my 53132As, an Agilent unit, s/n KR01202209 fail the power-on self > test with a FAIL:ROM error message. During the test the front > panel display > looks quite odd compared with the other counters. If I ignore the > error and > press Recall (my settings are in Recall 1) I can proceed to what > seems like > normal operation and the time intervals I have been collecting > for years on > this counter seem OK. > > > > I opened it up and there is not much there. While I suppose I > could perform > some simple tests like checking power supply outputs, I just > wondered if any > of you have had a similar experience or if you knew of a > reasonable place to > have it repaired. I can only imagine what Agilent would charge for this. > > ___ 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.
