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EBAY: Many faulty hp/agilent 34401a multimers
Posted by
teksturi
on 21 Nov, 2015 20:38
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Thanks for sharing!
I wonder what the deal is with that
34401A that's sold 'as-is'... they haven't even showed any errors!
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#2 Reply
Posted by
teksturi
on 21 Nov, 2015 20:49
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#3 Reply
Posted by
nctnico
on 21 Nov, 2015 21:08
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Neat tinkering object. I wouldn't pay the asking price though since it seems somebody else already went through them and deemed the meters beyond repair. All of them are missing the rear bezel as well for some reason. Maybe they got opened and damaged on purpose before decommisioning?
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#4 Reply
Posted by
teksturi
on 21 Nov, 2015 22:57
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Good points. May be still good deal to buy all off them. If seller agreed for 1000$ or something close for all units it may be winner deal. Unlucky or lucky (depends point) that I have wife. Love to see that kind of repair. Love to do that myself too but but the wife point
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#5 Reply
Posted by
MadTux
on 22 Nov, 2015 00:05
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Look at TiN's 3458A repair thread. And ask him if he would buy that 3458A again. Then think again about buying those potatoes for budget price.
Don't get me wrong, I really like fixing stuff. But there are limits to what is fun and pays off. Repairing drowned and severely neglected DMMs certainly isn't fun for me.
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#6 Reply
Posted by
nctnico
on 22 Nov, 2015 00:19
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It seems to me like these don't have water damage because they look much too clean for that. I'm more worried about the missing rear bezels. I doubt everything from this seller has been in water. That would make his stock run out pretty quick.
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#7 Reply
Posted by
EEVblog
on 22 Nov, 2015 00:22
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#8 Reply
Posted by
MadTux
on 22 Nov, 2015 00:34
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But what other possibilities are there for a company to produces 20+ dead DMMs? It seems to me that most of them have the same stickers on them, so they must originate from the same place.
Sure, one possibility is that one company dumped lots of working DMMs into dumpster, but why? And I would also expect most of them to work after beeing dumped and pulled from dumpster. From experience I can tell that higher end HP bench DMMs are really reliable, so it certainly takes lots of effort to kill 20+ meters. And I would guess that even the dumbest engineer would stop after the second or third.
Concerning the water damage: Look at the 'No Input reading' one, RS232 port on the rear. Clearly some corrosion going on there.
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#9 Reply
Posted by
Macbeth
on 22 Nov, 2015 00:42
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All of them are clearly faulty AND have been interfered with before (no doubt stripped/part swapped for the expensive/unobtanium parts like Caddock resistor arrays, ASICs, etc). Just look at the hell TiN has been through from dealing with this sellers crap. OldSchoolCool wisely got shut of his HP3458A from the same seller.
The asking prices are insane. Much like the $20,000+ asked for the rusty 3458As. These really are worth their scrap value alone. You would guess 3 meters to make 1 or 2 good'uns, except you find the rare parts just happen to be the ones missing/swapped in ALL of them.
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#10 Reply
Posted by
Macbeth
on 22 Nov, 2015 00:46
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But what other possibilities are there for a company to produces 20+ dead DMMs? It seems to me that most of them have the same stickers on them, so they must originate from the same place.
You clearly have never worked in a service shop. When I did you would be amazed at the amount of old skeletons and carcasses kept on shelves to rape for parts (with stickers!). Only when they were stripped of all the good stuff and/or we needed space would they be dumped.
Now guess were all that stuff ends up? On a slow boat to a third world country for cheap landfill where it is sorted by children into piles, then efficiently moved up various chains to end up on ebay after all the vultures have taken whats left of what could be the good stuff.
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#11 Reply
Posted by
MadTux
on 22 Nov, 2015 00:51
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No, never worked in a repair shop. But I certainly have experience in raping broken units for parts, as my lab mostly consists of cheap ebay instruments
But I wouldn't expect that any company, no matter how large, produces that much scrap that it keeps 20 or more of the same DMMs in stock to rape for parts, while it is still supported by Agilent. Anyone with a working mind would order replacement parts instead of new units.
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#12 Reply
Posted by
Macbeth
on 22 Nov, 2015 01:05
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Oh lord! Closer inspection of the "no faceplate" and the service tech has helpfully wrote "defective a/d chip" on the masking tape label.
Shudder!
I dunno where this Filipino seller gets his HP stuff, but he has form!
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#13 Reply
Posted by
nctnico
on 22 Nov, 2015 09:32
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Concerning the water damage: Look at the 'No Input reading' one, RS232 port on the rear. Clearly some corrosion going on there.
In a moist climate these connectors rust rather quickly. I've owned more HP gear with corroded sub-D and HPIB connectors (mostly the nuts) but the corrosion was definitely not caused by water damage. It is just poor surface treatment of the connector hardware.
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I have paid less on ebay Germany for broken 34401A meters and they were in better condition. This doers not seem to be a good deal.
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#15 Reply
Posted by
teksturi
on 22 Nov, 2015 11:33
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There are other interesting multimeter items like 21pcs Keithelys
2015 from same seller. Price is under 6000$. So one meter price will be about 300$. They say that every meter works and has been calibrated last year. And they from Nokia so I think they has been calibrated every year.
But price is way too high. Cosmetic conditions are not so great. And who want to risk 6000$ dollars. You can find this meters way cheaper from eBay.
I have paid less on ebay Germany for broken 34401A meters and they were in better condition. This doers not seem to be a good deal.
I have same though but if you can offer low price from all off them that's the different think. Then you may have spare parts. But hey, I just wanna see someone is going to try the repair
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#16 Reply
Posted by
teksturi
on 23 Nov, 2015 14:37
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Prices just go down 20%
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I wouldn't touch those with a barge pole. They are ALL missing the back bezel. And there is a reason for that. The back bezel holds the little sticker with the serial number of the machine.
This means one of two things :
1) These machines have been decomissioned. The serial number will be wiped from EEProm as well. You can not have these things officially calibrated as they are marked as 'scrap'.
2) these machines are really broken beyond repair or beyond economical repair so they have recycled the serials to other machines to 'erase' certain traces...
This stinks from a mile away. chances you can fix these are VERY slim.
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#18 Reply
Posted by
PedroDaGr8
on 23 Nov, 2015 15:51
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I wouldn't touch those with a barge pole. They are ALL missing the back bezel. And there is a reason for that. The back bezel holds the little sticker with the serial number of the machine.
This means one of two things :
1) These machines have been decomissioned. The serial number will be wiped from EEProm as well. You can not have these things officially calibrated as they are marked as 'scrap'.
2) these machines are really broken beyond repair or beyond economical repair so they have recycled the serials to other machines to 'erase' certain traces...
This stinks from a mile away. chances you can fix these are VERY slim.
Are you sure on that? I see the serial number sticker on 5 of 5 that i have checked so far. The serial number on these is on the back case on a sticker right above the VM Comp and Ext. Trig jacks.
That being said, my HP 34401A has a little sticker on the back bezel and no sticker on the back of the case. Interesting if that little one is the serial number for mine, I thought mine was sold without a sticker.
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#19 Reply
Posted by
nctnico
on 23 Nov, 2015 18:18
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Prices just go down 20%
I'm still happy they turned my $50 offer down
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#20 Reply
Posted by
MadTux
on 23 Nov, 2015 23:33
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Serial is still there, it's on the back of the aluminium chassis, not on the plastic frame which is missing.
http://www.amplifier.cd/Test_Equipment/Hewlett_Packard/HP_meter/images/HP34401A_back.jpgMore probable reason for missing back frame is, as already mentioned, that a few people messed with them before. First guy in some company probably opened and tested them, found that they are beyond economical repair and dumped them. Second guy, perhaps someone in association with the seller, opened them again and stripped all good parts, except CPU board, rubbery keypad and VFD, so they can show a 'working' unit on ebay.
One of these guys was lazy and didn't put the back frame back on. Perhaps the same guy that found it handy to have a few replacement VFD filter/cover plates.
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#21 Reply
Posted by
iampoor
on 23 Nov, 2015 23:54
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If someone who sells primarily test equipment sells units "as-is" its bad news.....
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#22 Reply
Posted by
Macbeth
on 23 Nov, 2015 23:59
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They are worth their VFD's - which isn't saying much, because half of them are totally shot, the rest just passable. The ridiculous postal charges make them not even worth scrap. Seller insists on very expensive courier delivery.
I seriously doubt there is a "ringing" industry in T&M gear with serial numbers being swapped around
. I mean, yes with cars and motorbikes there is the government agencies that hold a chassis number to a registered vehicle - and people often used to sell a logbook or V60 registration document along with a "chassis" which consists of nothing but a piece of metal with a VIN plate on it as a whole vehicle - which thieves then steal a vehicle and swap the plates and numbers around. It was a big problem back in the day, but I don't hear of it now.
But on crappy old 34401's
lol... Nope! I think someone is pulling our legs.
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#23 Reply
Posted by
Macbeth
on 24 Nov, 2015 00:02
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If someone who sells primarily test equipment sells units "as-is" its bad news.....
Just see what TiN has had to do with his 3458A from the same seller. New transformer, new voltage reference, repairs to power supply boards, repairs to A/D boards - replacement of A/D board. (Unobtanium parts). Anyone would think someone had took all the good boards and shoved in all the shit ones, even forgetting the VREF totally, and sell it on...
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#24 Reply
Posted by
iampoor
on 24 Nov, 2015 00:15
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If someone who sells primarily test equipment sells units "as-is" its bad news.....
Just see what TiN has had to do with his 3458A from the same seller. New transformer, new voltage reference, repairs to power supply boards, repairs to A/D boards - replacement of A/D board. (Unobtanium parts). Anyone would think someone had took all the good boards and shoved in all the shit ones, even forgetting the VREF totally, and sell it on...
Yep, I followed that "ordeal"....I honestly cant believe he persevered. I think I would have thrown it out a window.
Whenever I look at something "as-is" on Ebay, I would never consider purchasing it if the seller appears to know what they are talking about. Only 1 bad experience so far.
Im sure this seller would list the parts individually if there was anything of value.....they seem pretty scummy to me.
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#25 Reply
Posted by
FireFlower
on 26 Nov, 2015 04:10
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Yeah, those look very bad, might be from Nokia South-Korea factory from 2014 auction and most equipment that came from there after auction was horrendous, I still see nightmares opening those machines to clean up so we could use them... Actually the work still continues, lots of moisture damage and large machines had not been serviced long time
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#26 Reply
Posted by
TiN
on 27 Nov, 2015 06:29
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...
Just see what TiN has had to do with his 3458A from the same seller. New transformer, new voltage reference, repairs to power supply boards, repairs to A/D boards - replacement of A/D board. (Unobtanium parts). Anyone would think someone had took all the good boards and shoved in all the shit ones, even forgetting the VREF totally, and sell it on...
Well, to be 100% fair, I got what I asked for that price point, really. I'm not seeing how anyone could get properly working 3458 for less then 3K$ in any way, unless someone just give it as a generous gift. Many of those "good" 3458 up for sale now are there for months, and still might have number of hidden issues, like drift of ADC or some intermittent issues. I just chosen the hard way. Would I do again knowing all what I do now? Yes, I think so, it's crazy project to do.
P.S. Not saying those 34401a worth it, though. Completely different class of device, with plenty of better/cheaper alternative around.
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#27 Reply
Posted by
hendorog
on 30 Nov, 2015 21:57
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I took a punt on the as-is one mentioned above, and put in a low offer.
It has just arrived this morning and it actually does work and show reasonable values - so far anyway!
The display is pretty dim, and only just readable in the menus. However it is OK in my environment when actually measuring values.
I had a quick play in the menu without knowing what I was doing:- Tests pass, there are no errors and calibration message shows a date in 1993.
Cal count is 146 if I am reading it right, which seems pretty high.
Inside it looks as you would expect for an old instrument. No water damage at least.
Shipping was expensive (cost more than the meter), but it was DHL and so arrived very quickly.
Total cost was $150 USD including delivery to New Zealand.
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#28 Reply
Posted by
Macbeth
on 30 Nov, 2015 23:33
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The weird dots on the display put me off that one. Are they still there?
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#29 Reply
Posted by
hendorog
on 01 Dec, 2015 00:06
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#30 Reply
Posted by
Macbeth
on 01 Dec, 2015 00:39
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Perhaps a trick to wring the last possible life out of a worn VFD is to overdrive it, in which case the very rarely (if ever) used segments like those top part of a colon : symbol dots will be lit up. The bottom dots not so much as they will have been in use as decimal points.
This one
http://www.ebay.com/itm/252179072641 looks like they went overboard on the over volt/current hack
I guess you got the best of an awful bunch, just need a new VFD.
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those dots are caused by leaky VFD drivers. they are TI parts. obsolete and replaced by pericom . i have posted the xref before on the forum.
these are 32 bit high voltage shift registers in plcc44 package. replace em and the problem is solved.
Note : if you have a really old 34401 then the VFD is driven by a upd75xxx custom cpu with integrated drivers . That one is unobtainium....
and the fronts are not interchangeable... a newer 8051 based frontpanel does not work in a machine that needs the upd75xxx based one.
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#32 Reply
Posted by
hendorog
on 01 Dec, 2015 01:03
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those dots are caused by leaky VFD drivers. they are TI parts. obsolete and replaced by pericom . i have posted the xref before on the forum.
these are 32 bit high voltage shift registers in plcc44 package. replace em and the problem is solved.
Note : if you have a really old 34401 then the VFD is driven by a upd75xxx custom cpu with integrated drivers . That one is unobtainium....
and the fronts are not interchangeable... a newer 8051 based frontpanel does not work in a machine that needs the upd75xxx based one.
Thanks for the info. I'll check it out tonight and see. This one is pretty old so could well be the latter.
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#33 Reply
Posted by
hendorog
on 01 Dec, 2015 01:06
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Perhaps a trick to wring the last possible life out of a worn VFD is to overdrive it, in which case the very rarely (if ever) used segments like those top part of a colon : symbol dots will be lit up. The bottom dots not so much as they will have been in use as decimal points.
This one http://www.ebay.com/itm/252179072641 looks like they went overboard on the over volt/current hack
I guess you got the best of an awful bunch, just need a new VFD.
Yep - at least its working better than my ex Navy Fluke 8600A (Nicad version) - that thing blew a big cap covering everything in crap and melting the case!
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The 34401A even sells well for 351 euros as a used one, when marked as "Keithley" on ebay Germany
LOL
Keithley-34401A-Digital-Multimeter-6-Digithttp://www.ebay.de/itm/281870590929
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#35 Reply
Posted by
MadTux
on 08 Dec, 2015 00:26
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#36 Reply
Posted by
Vgkid
on 08 Dec, 2015 00:52
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I would easily grab the cheapest one, but shipping kills it. Plus who knows the fate of the insides.
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#37 Reply
Posted by
Macbeth
on 08 Dec, 2015 01:13
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The 34401A even sells well for 351 euros as a used one, when marked as "Keithley" on ebay Germany
LOL
Keithley-34401A-Digital-Multimeter-6-Digit
http://www.ebay.de/itm/281870590929
It's odd that it went for such a high price... Unless the buyer is going to rely on the listing being wrong/fraudulent and playing that card. I hope not, despite it being guaranteed by ebay policy to work against the seller and award the scam artist.
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#38 Reply
Posted by
MadTux
on 08 Dec, 2015 01:28
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It's odd that it went for such a high price... Unless the buyer is going to rely on the listing being wrong/fraudulent and playing that card. I hope not, despite it being guaranteed by ebay policy to work against the seller and award the scam artist.
Probably because HP/Agilent/Keysight/Whatever changed names so often, people are searching for 34401A only, instead for HP 34401A, Agilent 34401A etc separately. Thereby only correct number is needed. Keithley keyword also helps.
I would easily grab the cheapest one, but shipping kills it. Plus who knows the fate of the insides.
Really??? 3456As in unknown, but nearly 100% fixable condition usually go for as low as $60-90 on US ebay. Here, the truely broken one costs 80$ and you have to pay expensive shipping to get an instrument that is basicallly ruined with water/corrosion crap inside.
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#39 Reply
Posted by
Vgkid
on 08 Dec, 2015 01:49
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I should have said that I would pay that much if it was not sold by that seller(and located stateside). The Analog Devices cal sticker from 2011 does pique my interest.
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34401 should go for about 300$ in pristine condition.
Agilent has put these things on life support. they are discontinued ( or soon to be )
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About a year ago, they still sold for much higher prices in the US
Now it seems they sell for more in Europe
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#42 Reply
Posted by
eas
on 08 Dec, 2015 09:08
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34401 should go for about 300$ in pristine condition.
Perhaps, but they seem to be going for more than that lately.
Agilent has put these things on life support. they are discontinued ( or soon to be )
Dec 1, 2016.
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those dots are caused by leaky VFD drivers. they are TI parts. obsolete and replaced by pericom . i have posted the xref before on the forum.
these are 32 bit high voltage shift registers in plcc44 package. replace em and the problem is solved.
Note : if you have a really old 34401 then the VFD is driven by a upd75xxx custom cpu with integrated drivers . That one is unobtainium....
and the fronts are not interchangeable... a newer 8051 based frontpanel does not work in a machine that needs the upd75xxx based one.
Bought a 34401A on Ebay and it seems to have this hardware fault. The driver IC is between the screen and PCB so I can not see the text on them. Is there a way to determine what is in there without taking it apart? there are some texts on the screen module like 0795 which looks like a data code to me. the text 34401-66502 and there is also a sticker with a bar-code and the code 5CF0052. I am afraid I can see a 42 pin trough hole dill part ... does this mean it is unrepairable?
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Hey mate, this thread was last updated in 2015. Not sure anyone will come back, maybe start a fresh thread.
(no not..haha, glad I was wrong).
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Is your 34401A really old with only red 4mm input color rings?
Then it is most likely the very old type.
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HP brand are they the ones with unfindable and unreplacables vfd chips
if you get the model keysight or agilent with red and black input plugs you may get lucky to have a repairable one
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#47 Reply
Posted by
corn11
on 05 Mar, 2018 15:32
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Not necessarily, only the early ones have the old front panel board with the NEC µC. Those front panel boards have another part number 34401-66502. If you look in the backdating section of the service manual you can (probably) identify the DMMs with the old FP by the serial number.
Otherwise the red rings on the negative jacks as HighVoltage mentioned are probably also a good indicator.
According to the service note 06 it also seems like that you can replace the old panels with the NEC µC (34401-66502) by the new ones (34401-66512) if you update the firmware:
http://literature.cdn.keysight.com/litweb/pdf/34401A-06.pdf
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If someone who sells primarily test equipment sells units "as-is" its bad news.....
A-men to that! That's why I NEVER buy anything "as-is" from Tucker or other major equipment dealers. You can be SURE that the units have been stripped of anything usable before the carcass gets dumped on E-Greed.
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#49 Reply
Posted by
Zucca
on 06 Mar, 2018 15:11
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