Author Topic: Agilent 1670G - I Killed it - Opinions  (Read 12868 times)

0 Members and 1 Guest are viewing this topic.

Offline Armadillo

  • Super Contributor
  • ***
  • Posts: 1725
  • Country: 00
Re: Agilent 1670G - I Killed it - Opinions
« Reply #25 on: July 27, 2017, 06:23:43 pm »
Better not classify it as foreign object, could be native resident object like poorly fastened screws or loose wires, conductive spills whatsoever.

Poor seller, but if it will to cut your heart into pieces everyday, then just bite it. Too bad you enjoyed the seconds of operation.
Poor buyer, just return it as non operational then negotiate for some relieves.
 
 

Offline TerraHertz

  • Super Contributor
  • ***
  • Posts: 3958
  • Country: au
  • Why shouldn't we question everything?
    • It's not really a Blog
Re: Agilent 1670G - I Killed it - Opinions
« Reply #26 on: July 28, 2017, 01:09:20 am »
Definitely do not attempt to unsolder that row of pins to separate the two boards. If you are a beginner at this, you are very likely to damage the PCB traces while doing that. Which then eliminates the option to return it to seller as faulty.

It could have been just dust that arced when you disturbed it, though from your photo it doesn't appear dusty. I had a PC power supply that blew up due to dust accumulation only.
Another possibility is tin whiskers. Those heatsinks look like they are tin plated, and maybe have some tin surface roughness developing. It's an obscure problem, google 'tin whiskers'. It has been discussed a few times here. Tin plated metal surfaces tend over time to grow ultra-fine long whiskers of pure tin. You might have blown one of them loose.

Or, you were just super unlucky and blew an old iron filing or something into the wrong spot.
If you remember where the flash seemed to be, closely inspect that area with a magnifying glass. There should be some evidence of what went phut. Cracked component, bright arc-points on metal, dark flash-metalization on nearby surfaces.
Collecting old scopes, logic analyzers, and unfinished projects. http://everist.org
 

Offline tablatronix

  • Regular Contributor
  • *
  • Posts: 199
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #27 on: July 28, 2017, 12:39:24 pm »
Try using a uv light to look for patterns also makes certain things easier to see, fluids, carbon, darkened pcb areas
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #28 on: July 28, 2017, 01:11:14 pm »
Try using a uv light to look for patterns also makes certain things easier to see, fluids, carbon, darkened pcb areas

Thats a really useful tip, thanks for pointing it out.
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #29 on: July 28, 2017, 06:34:32 pm »
So I spoke with the seller.  I told them what happened and they agreed to split the cost of the unit.  I think that was fair.  So I now own this non-working 1670G for $135.  So I am going to get some additional pictures tonight, it's my "night off."

Thanks for all of your help and input.  I am going to follow as much of the advice as I can.
 

Offline CJay

  • Super Contributor
  • ***
  • Posts: 4136
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #30 on: July 28, 2017, 06:36:04 pm »
Well that's a result, good seller and a clear conscience for you as well as a bargain!
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #31 on: July 28, 2017, 06:46:20 pm »
Well that's a result, good seller and a clear conscience for you as well as a bargain!

Best of both worlds, turns out they actually do some repairs on stuff then resell, so they know the drill.  Great case of a seller also acting with honestly and integrity.  I have a lot of positive things to say about the eBay community by and large.
 

Offline Armadillo

  • Super Contributor
  • ***
  • Posts: 1725
  • Country: 00
Re: Agilent 1670G - I Killed it - Opinions
« Reply #32 on: July 28, 2017, 07:14:45 pm »
I think the Good Seller name deserves a mention here so that the community can benefits in patronizing his shop as well.  Win Win ;D
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #33 on: July 28, 2017, 10:12:53 pm »
You did well there then. The repair is more than likely to be something quick and simple to do as well so hopefully you'll end up with a 1670G at a bargain price.
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #34 on: July 29, 2017, 07:36:34 am »
Winnah winnah chicken dinnah!

Had a "second squizz" and was getting some pics and I found a fuse.  Someone posted it was probably covered in heat shrink tubing and they were spot on.  I couldn't see it very well, so I buzzed it out and no continuity.  Then I put it under the Andostar microscope and got this shot.  Looks like it did it's job, and I have a starting point.

I am going to get more pics in the morning and get the hive's opinion on how to get this sucker out.  It appears to be soldered on one side but there is a "sleeve" where it is soldered for lack of a better term, but it doesn't want to come out easily, the other side was in a socket and it just slid right out of that side.
« Last Edit: July 29, 2017, 07:50:25 am by CoalCreekPlastics »
 

Offline CJay

  • Super Contributor
  • ***
  • Posts: 4136
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #35 on: July 29, 2017, 08:16:58 am »
Weird thing to say but that fuse hasn't died 'violently', if it was a catastrohic failure I'd expect the glass to be spattered with metal or even shattered.

Chances are the failure is a minor one, if you're lucky you may even get away with just replacing the fuse BUT you must check for problems before you replace it and power on or you cold end up making matters far worse.

As someone else mentioned the filter capacitors are of a type that's prone to failure and would cause a fuse to blow
 
The following users thanked this post: buck converter

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #36 on: July 29, 2017, 11:01:24 am »
Once you have replaced the fuse, and looked around for any signs such as filter caps blown etc and corrected anything that you can see, power it up either via a variac transformer if you one or use the dim type approach by connecting a low wattage light bulb (not a low energy type) in series with it to limit any current in the event that there is still a problem. If it powers up fine, then plug it in the normal way.
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline andy2000

  • Frequent Contributor
  • **
  • Posts: 254
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #37 on: July 30, 2017, 03:45:39 pm »
It wouldn't hurt to put an ohm meter across the power line input after you replace the fuse.  Also, you can check the resistance across the main primary side filter cap.  If either is a low resistance, you have shorted parts that need to be replaced. 

I agree that what you did probably wasn't the cause.  These things just aren't that fragile.  Probably a foreign object, loose part, or coincidence.  If a device is going to fail, it will often do so just seconds after powering it on. 

Just recently I was working on a computer.  Everything was fine until I flipped it on its side to access something.  Immediately, there was a bang and a flash and the system went dead.  It turned out that a large coil had come loose and rubbed against a heat sink (in shipping) until the insulation on the coil was damaged.  When I flipped it on its side, the coil touched the heat sink and shorted.  Fortunately, it only damaged the coil and blew the fuse. 
 

Offline TerraHertz

  • Super Contributor
  • ***
  • Posts: 3958
  • Country: au
  • Why shouldn't we question everything?
    • It's not really a Blog
Re: Agilent 1670G - I Killed it - Opinions
« Reply #38 on: July 31, 2017, 09:38:15 am »
I'm starting to think maybe 'coincidence'. That suspect power line filter cap (the one with the honey-colored clear plastic case) really is a highly suspect part. They are notorious for blowing up soon after powering up equipment that has been unused for a few years. By 'soon after' I mean within minutes. Even if they are still good, you should replace them on sight.
Their failure mode is, the plastic case shrinks and cracks, letting moisture into the roll of metalized foil. Then a short circuit forms between the metalization layers, but it doesn't draw a lot of current because the metalization is so thin it just vaporizes around the short. But the arc keeps chewing away at the plastic and metal foil. Usually they emit some foul smelling smoke (and you'd definitely know it if this happened), but it's possible the fuse blew before it got that bad. The 'gently blown by moderate overcurrent rather than a dead short' state of that fuse is what makes me suspect that cap more.

Of course it's always possible for old fuses to just fail for no good reason. If you can't find anything obvious wrong, it's worth trying a soft power-up (light bulb or variac to limit current) with a new fuse.

Anyway, you won't be doing dust-blowing maintenance on anything with the power on in future, will you! Because ambiguity.
« Last Edit: July 31, 2017, 09:44:26 am by TerraHertz »
Collecting old scopes, logic analyzers, and unfinished projects. http://everist.org
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #39 on: July 31, 2017, 08:19:49 pm »
I'm starting to think maybe 'coincidence'. That suspect power line filter cap (the one with the honey-colored clear plastic case) really is a highly suspect part. They are notorious for blowing up soon after powering up equipment that has been unused for a few years. By 'soon after' I mean within minutes. Even if they are still good, you should replace them on sight.
Their failure mode is, the plastic case shrinks and cracks, letting moisture into the roll of metalized foil. Then a short circuit forms between the metalization layers, but it doesn't draw a lot of current because the metalization is so thin it just vaporizes around the short. But the arc keeps chewing away at the plastic and metal foil. Usually they emit some foul smelling smoke (and you'd definitely know it if this happened), but it's possible the fuse blew before it got that bad. The 'gently blown by moderate overcurrent rather than a dead short' state of that fuse is what makes me suspect that cap more.

Of course it's always possible for old fuses to just fail for no good reason. If you can't find anything obvious wrong, it's worth trying a soft power-up (light bulb or variac to limit current) with a new fuse.

Anyway, you won't be doing dust-blowing maintenance on anything with the power on in future, will you! Because ambiguity.

LOL, no, no more "live dusting."  Because...I can count to potato.

I am looking at buying a variac just for this project and because SMPS are a domain and skill I want to own going forward.

I am looking at the filter caps, and trying to figur out how to get this damn fuse out without tearing stuff up.
« Last Edit: July 31, 2017, 09:37:28 pm by CoalCreekPlastics »
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #40 on: July 31, 2017, 09:39:39 pm »
Sorry for such a noob question, but how do I get this fuse out of that socket?  Do I need to de-solder it?

 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #41 on: July 31, 2017, 10:50:35 pm »
It looks to me like it is pushed into a cup on a floating wire, if thats the case simply pull it out like you did the fixed cup on the PCB. If its not pushed into a cup then, yes, you will need to unsolder it.
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline WastelandTek

  • Frequent Contributor
  • **
  • Posts: 609
  • Country: 00
Re: Agilent 1670G - I Killed it - Opinions
« Reply #42 on: July 31, 2017, 11:15:20 pm »
those can be tight as hell

destruction of the fuse may be necessary
I'm new here, but I tend to be pretty gregarious, so if I'm out of my lane please call me out.
 

Offline gnif

  • Administrator
  • *****
  • Posts: 1672
  • Country: au
Re: Agilent 1670G - I Killed it - Opinions
« Reply #43 on: July 31, 2017, 11:22:48 pm »
Winnah winnah chicken dinnah!

Had a "second squizz" and was getting some pics and I found a fuse.  Someone posted it was probably covered in heat shrink tubing and they were spot on.  I couldn't see it very well, so I buzzed it out and no continuity.  Then I put it under the Andostar microscope and got this shot.  Looks like it did it's job, and I have a starting point.

I am going to get more pics in the morning and get the hive's opinion on how to get this sucker out.  It appears to be soldered on one side but there is a "sleeve" where it is soldered for lack of a better term, but it doesn't want to come out easily, the other side was in a socket and it just slid right out of that side.

I wonder if the sudden freezing of the cold fuse would cause the metal to thermally shrink and break, or become too thin and just simply blow.
 

Offline Bushougoma

  • Regular Contributor
  • *
  • Posts: 72
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #44 on: August 01, 2017, 12:35:27 am »
TerraHertz beat me to it.

Replace those yellow Rifa X caps they are known to fail short circuit (usually with quite a bit of smoke) and blow the line fuse.

Look at the epoxy body and you will no doubt find fine hairline cracks. These are replace on sight parts it's not if they will fail it's when.

Seeing those on the power supply leaves little doubt in my mind that the air duster was just a coincidence.

Sorry for such a noob question, but how do I get this fuse out of that socket?  Do I need to de-solder it?

That's not a socket it's part of the fuse it's called an axial fuse it's not meant to be separated from the leads. You'll need to desolder it.
« Last Edit: August 01, 2017, 01:01:25 am by Bushougoma »
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #45 on: August 01, 2017, 07:05:51 am »

I wonder if the sudden freezing of the cold fuse would cause the metal to thermally shrink and break, or become too thin and just simply blow.

I Seriously doubt that was possible.  We are talking about a micro-burst here and the fuse was behind the fan and case, covered with heat-shrink tubing.

I have the fan under the microscope now examining the are where I saw the spark.  The consensus seems to be the filter caps are suspect.  They are coming out and a variac is being sourced on eBay.  This won't be my last power supply work I suspect.
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #46 on: August 07, 2017, 07:08:09 am »
Someone was expecting a more dramatic fuse blow.  I pulled out the second fuse I found after it didn't buzz out.
 Here it is.
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #47 on: August 07, 2017, 07:16:19 am »
So suspect caps and blown fuses sucked out.  These are the before and after pics.  Need to clean the rosin off and I hope I didn't scorch the s**t out of this board.  No traces came up or anything so hoping it's not bad for a ham-handed amateur.  :-BROKE

Lost my bid for a sweet new-ish clean Superior Electric Variac on eBay tonight...sad panda.  Most of them seem pretty old and crusty.  Based on the variac thread trying to avoid the "One Hung Low" brand units.  Don't need a house fire right now.

Now to source replacement caps and fuses.  Thanks for all the help from the forum!
 

Offline CoalCreekPlasticsTopic starter

  • Supporter
  • ****
  • !
  • Posts: 65
  • Country: us
Re: Agilent 1670G - I Killed it - Opinions
« Reply #48 on: August 07, 2017, 07:32:04 am »
And last picture set, here are our suspect turd filter caps.  Have not done a close inspection on these yet.  The axial fuses were 10A 250V, the small RIFA caps were 4n7 Y2 and the larger ones were 15n Y2.  I welcome any suggestions on replacements, I have found a few candidates that have the same box style package, but again, I am still learning.

Thanks again!

ETA: I went ahead and got some close-ups of the RIFA caps on each side.  I need to go back over the thread but I thought someone said to look for cracks.  I may have squeezed them getting them out but they all seem to show "hairline" cracks. 

This has been great I have learned so much.  Dave Jones and this forum have enhanced my understanding tremendously.  Just weeks ago I would not have been able to suck these components out!
« Last Edit: August 07, 2017, 07:57:53 am by CoalCreekPlastics »
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Agilent 1670G - I Killed it - Opinions
« Reply #49 on: August 07, 2017, 07:38:47 am »
I would say that once you replace these, there is a very good chance it booting up and working once again, well done. :-+
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 
The following users thanked this post: CoalCreekPlastics


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf