You may not have as big of a channel as EEVBlog yet, but you've got a steller community with some brilliant minds. Glad we were able to get this unit back in service completely! Side note... I guess switches are HP's weakness, just like how older flukes constantly seem to have LCD issues...
yes, we've repaired a lot of HP34401A in the same manner / similar faults on eevblog .. but please be aware , that all that stuff is >20 years old, before these switches deteriorate. I would not call this a 'weakness', but a normal wear and tear . 'Dr. Frank'
Well, I think there is no comparison between Marc’s and Dave’s channel, or communities. Ignoring for a while the ignorance of Dave regarding tech he does not understand fully, I don’t remember him actually repair something.
Years repairing various devices, I learned something: Rarely any dedicated chip is the culprit. I believe that, due to them being special and rare/expensive they are made with lots of protections so they are hard to break. Of course this is a theory.
That has not been my experience. The higher end HP 3458 DVMs are known for having proprietary hybrid failures (see th-cam.com/video/upTgM_S5rAQ/w-d-xo.html ), as well as the HP 8112 / 8116 generators (see th-cam.com/video/LJ-PsPow10M/w-d-xo.html ). The proprietary ECL chip failed on my HP 8082A (see th-cam.com/video/09zhUbJl37w/w-d-xo.html ), and the proprietary Nixie driver failed on my HP 5327B (see th-cam.com/video/vKxobfvrt-I/w-d-xo.html ). Not sure they fail the same or more often than other non proprietary parts, but when they fail it is way more difficult to repair - or just plain impossible, like in the HP 3458 case.
This hits about 50% on the Mend It Mark to Marco Reps scale. It's also right in the "I have no idea what is going on but I enjoy your funny words" zone of the scale. Perfect for relaxing on the couch after work.
It surprised me that outgassing causes contact contamination which may mean that more frequent or periodic operation can prevent some failures. Use it or lose it!
Oh yeah, old plastic can have all kinds of nasty surprises. The plasticizers can not only deposit themselfs onto other surfaces, they can also chemically react with other stuff. And, with the plasticizers gone from the plastic parts, they can have a tendency to snap or even crumble.
Nice work getting it fixed. I don't do anything with my own projects that requires such precision, but I'm still seriously considering buying one of these units just because of how gorgeous it is.
I don't have the skills nor tenacity of Marc nor @Reps, and not to promote western overseas stuff... but used HP (Agilent/Keysight)/Fluke/R&S, etc. is out of my budget and ended up going with some Rigol and Siglent gear and have been very happy with it.
Well done Marc! To be honest, I was surprised to see that HP had used an open wafer switch for the front/rear control. It seems to me that it's almost asking to become contaminated. Might it have been a non-original configuration/service replacement item?
No, that's the original. Remember, this is the "low cost" instrument of the lineup, and not just by a little bit. However you can see they were still concerned about it, that's the only (thick) gold plated switch in there, and it has two sliders per contact. The other push button switches are not gold plated in this instrument. On the 6 digit, more expensive HP 3478, they could afford a better enclosed gold coated switch - but it failed just as well too...
@@lerkzor Thanks! I wonder what Elvie would think of today's clusterfuck. One hopes he would be aghast. We need a new forum for guitar amp/politics... I'll go start a Reddit.
this might be a stupid question he is calibrating old stuff with new technology. how did we measure electricity from 1752 to current times what was that progression like
Excellent! Much easier than making a new hybrid! Glad another one is saved.
Deoxit really need to send Marc a big boxful of the stuff, he's proved again and again that it really is the universal elixir for aged electronics!
You may not have as big of a channel as EEVBlog yet, but you've got a steller community with some brilliant minds. Glad we were able to get this unit back in service completely! Side note... I guess switches are HP's weakness, just like how older flukes constantly seem to have LCD issues...
yes, we've repaired a lot of HP34401A in the same manner / similar faults on eevblog .. but please be aware , that all that stuff is >20 years old, before these switches deteriorate.
I would not call this a 'weakness', but a normal wear and tear .
'Dr. Frank'
I just picked up a Fluke 8840A and the front/rear select switch is faulty
Well, I think there is no comparison between Marc’s and Dave’s channel, or communities. Ignoring for a while the ignorance of Dave regarding tech he does not understand fully, I don’t remember him actually repair something.
Years repairing various devices, I learned something: Rarely any dedicated chip is the culprit. I believe that, due to them being special and rare/expensive they are made with lots of protections so they are hard to break. Of course this is a theory.
Makes me miss the days *before* planned obsolescence
oloco! tabajara labs!!!
That has not been my experience. The higher end HP 3458 DVMs are known for having proprietary hybrid failures (see th-cam.com/video/upTgM_S5rAQ/w-d-xo.html ), as well as the HP 8112 / 8116 generators (see th-cam.com/video/LJ-PsPow10M/w-d-xo.html ). The proprietary ECL chip failed on my HP 8082A (see th-cam.com/video/09zhUbJl37w/w-d-xo.html ), and the proprietary Nixie driver failed on my HP 5327B (see th-cam.com/video/vKxobfvrt-I/w-d-xo.html ). Not sure they fail the same or more often than other non proprietary parts, but when they fail it is way more difficult to repair - or just plain impossible, like in the HP 3458 case.
Yay community! ❤
This hits about 50% on the Mend It Mark to Marco Reps scale. It's also right in the "I have no idea what is going on but I enjoy your funny words" zone of the scale. Perfect for relaxing on the couch after work.
The Marco Reps scale goes up to 11!
Congrats getting your HP DVM working glad it wasn't the hybrid.
Glad you were able to sort it out.
🥳 Hooray! Another fine piece of DVM saved!
YAY Marc and thanks to the commenters too.
Back when repairing it was an intended use case.
7:37 when you pressed really hard the number went from five to eight fwiw
Excellent! Glad it wasn't the hybrid. 👍
Awesome, I love our community and Happy New Year to you all !!
It surprised me that outgassing causes contact contamination which may mean that more frequent or periodic operation can prevent some failures.
Use it or lose it!
Oh yeah, old plastic can have all kinds of nasty surprises. The plasticizers can not only deposit themselfs onto other surfaces, they can also chemically react with other stuff. And, with the plasticizers gone from the plastic parts, they can have a tendency to snap or even crumble.
i remember the moment when Marc said... I don't need to disassemble this one, I will just give it a squirt.
I have nooooo memory of that.
Nice work getting it fixed. I don't do anything with my own projects that requires such precision, but I'm still seriously considering buying one of these units just because of how gorgeous it is.
I don't have the skills nor tenacity of Marc nor @Reps, and not to promote western overseas stuff... but used HP (Agilent/Keysight)/Fluke/R&S, etc. is out of my budget and ended up going with some Rigol and Siglent gear and have been very happy with it.
I love when the solution is simple.
Good job commenters 🎉🎉🎉🎉
Yay! Nice save!
Glad you got it fixed but was looking forward to a hybrid replacement design and fit 🙂
Well done Marc!
To be honest, I was surprised to see that HP had used an open wafer switch for the front/rear control. It seems to me that it's almost asking to become contaminated. Might it have been a non-original configuration/service replacement item?
Same here. Open switch not a good thing ever.
No, that's the original. Remember, this is the "low cost" instrument of the lineup, and not just by a little bit. However you can see they were still concerned about it, that's the only (thick) gold plated switch in there, and it has two sliders per contact. The other push button switches are not gold plated in this instrument. On the 6 digit, more expensive HP 3478, they could afford a better enclosed gold coated switch - but it failed just as well too...
Deoxid Gold, the duct tape of vintage electronic repair.
Wow! TH-cam comments actually solved something!😮
I was thinking that the adjustment pots could need some deoxit?
They may be dirty as well.
And possible the actual connectors themselves.
Dam you switches! * shakes fist *
Brilliant!
Love DeOxit... ProGold! Magic goo. Good old Lord Valve, curmudgeon of Denver, keeper of alt.guitar.amps flames.... hipped me to it. RIP.
I haven't thought of newsgroups in a long time. Thanks for the nostalgic blast, and RIP Lord Valve; I never knew you, but you are remembered still.
@@lerkzor Thanks! I wonder what Elvie would think of today's clusterfuck. One hopes he would be aghast. We need a new forum for guitar amp/politics... I'll go start a Reddit.
👍👍
Nice!
this might be a stupid question he is calibrating old stuff with new technology. how did we measure electricity from 1752 to current times what was that progression like
World team work
The Wisdom of Crowds strikes again!
Another happy ending!
✌️
Only shows that you need to find the actual root cause and not jump to conclusions that it cannot be fixed.
Nice troubleshoot. HI7/N2CQR