Magic smoke blows up! 34401A

[dimmog]

Latest ebay find. Magic smoke blows up here!

Poor HP/Agilent 34401A

[TheSteve]

OK, you win, that is the ugliest 34401A I've seen to date(and I bought one that had a hole drilled all the way through case and board).

[Gyro]

Wow. Did somebody try to measure lightning? 

At least the MOVs and Spark gap look intact! 

[Specmaster]

Latest ebay find. Magic smoke blows up here!

Poor HP/Agilent 34401A

Wow, thats fit for the bin, did you buy it and it blew up or what?

[strawberry]

Challenge accepted
I think, front end should be still alive

[thinkfat]

That's just too far gone.

[dimmog]

Latest ebay find. Magic smoke blows up here!

Poor HP/Agilent 34401A

Wow, thats fit for the bin, did you buy it and it blew up or what?

I bought it on ebay https://www.ebay.com/itm/255153918046
A little worried about the pungent smell of burning right out of the shipping box.

[xrunner]

I bought it on ebay https://www.ebay.com/itm/255153918046
A little worried about the pungent smell of burning right out of the shipping box.

I think your deal stinks. 

[Cerebus]

Wow, you've got to try quite hard to do that much damage to a 34401A.

[Cerebus]

Wow. Did somebody try to measure lightning? 

At least the MOVs and Spark gap look intact! 

Two of the MOVs look intact. There should be a third MOV to the side of the front terminals. I don't think it's there any more!

[Gyro]

Looking at the first (wider scale) photo in the OP, the third one may actually still be there too.

I wonder if someone seriously exceeded the common mode voltage limit with a high energy source.

[floobydust]

It carbon tracked and arced to the Front Panel board, all is toast. Exploded PLCC, kapton tape on the electrolytic tops?
Only seen this much carnage with a MOT and someone extra stupid to let it arc for a very long time.

[AVGresponding]

Good grief... whomever did that should be made to lick the pcb clean.

Whilst it's true anything can be repaired, the time and cost to fix that would be completely impractical. Hopefully there are enough surviving parts to recoup some of your costs!


I wonder if we should add a new award to the TEA thread, "The McCoy Award", or the "Dead Parrot Award" both spring to mind.

[bdunham7]

OK, you win, that is the ugliest 34401A I've seen to date(and I bought one that had a hole drilled all the way through case and board).

I've been trying to figure out what demented company it is that drills their TE before selling it to the surplus dealers.  Any idea?  And b/t/w, I know first okay, second hand that whoever they are, their selling agent does not disclose that the items have been drilled. 

[TheSteve]

It carbon tracked and arced to the Front Panel board, all is toast. Exploded PLCC, kapton tape on the electrolytic tops?
Only seen this much carnage with a MOT and someone extra stupid to let it arc for a very long time.

Kapton tape on top of the electrolytic caps is factory.

"What do we have on the spacecraft that's good?" seems appropriate here.

[AVGresponding]

OK, you win, that is the ugliest 34401A I've seen to date(and I bought one that had a hole drilled all the way through case and board).

I've been trying to figure out what demented company it is that drills their TE before selling it to the surplus dealers.  Any idea?  And b/t/w, I know first okay, second hand that whoever they are, their selling agent does not disclose that the items have been drilled.

Demilitarisation?

Surely not disclosing this sort of thing will result in a marked lack of repeat customers?

[TheSteve]

OK, you win, that is the ugliest 34401A I've seen to date(and I bought one that had a hole drilled all the way through case and board).

I've been trying to figure out what demented company it is that drills their TE before selling it to the surplus dealers.  Any idea?  And b/t/w, I know first okay, second hand that whoever they are, their selling agent does not disclose that the items have been drilled.

Well in my case it was advertised that a hole had been drilled through the entire thing, and it was pretty obvious looking at the case. That is what made me want it(yeah, I'm broken). Someday I'll post the repair of my Datron 4920M that had been decommissioned by hammer.

34401A repair: https://www.eevblog.com/forum/repair/34401a-repair-(had-a-hole-drilled-through-it)/

I have some parts 34401A PCB's, wonder if a working unit could be made.

[Stray Electron]

OK, you win, that is the ugliest 34401A I've seen to date(and I bought one that had a hole drilled all the way through case and board).

I've been trying to figure out what demented company it is that drills their TE before selling it to the surplus dealers.  Any idea?  And b/t/w, I know first okay, second hand that whoever they are, their selling agent does not disclose that the items have been drilled.

   The only place that I've ever seen that done was on De-Militarized equipment.

[joeqsmith]

I would like to hear the story behind it.   

[WattsThat]

I would like to hear the story behind it.

I’ll second that. If the person was still upright when it was over, I’ll bet they needed a clean pair of tighty whities.

A Jerry Lee Lewis song lyric comes to mind: “Goodness gracious, great balls of fire”

That had to be several kilovolts to create that area of flash-over, unless the board was contaminated. Even so, it would take some mighty high voltage to do that and more than a few watts required to vaporize that missing MOV. Scary stuff.

[joeqsmith]

Looks like the MOVs and GDTs are all there.  The trace may have saved it from further damage.  Maybe the current owner will clean it up and post a few pictures. 

[WattsThat]

Ah, you’re correct. I thought RV101 was missing but it turns out it is a black device, not the blue, somewhat hidden in the shadows. It does appear that R104 and 105 in the input chain are vaporized, I mistook that area for RV101.

[bdunham7]

I wonder if someone seriously exceeded the common mode voltage limit with a high energy source.

That's probably the best guess so far.  Perhaps trying to measure the current of a high-voltage source like a MOT or worse?  I'd like to see the case and covers around that area. 

[MadTux]

I wonder if someone seriously exceeded the common mode voltage limit with a high energy source.

That's probably the best guess so far.  Perhaps trying to measure the current of a high-voltage source like a MOT or worse?  I'd like to see the case and covers around that area.

In that case, transformer might have arced over inside and inguard logic might be toasted too, first thing I would test is supply inguard with 5V logic voltage and see, if it's shorted. If so, that thing is a paper weight and only useful as a source for case parts, which actually still look quite good 

[Cerebus]

What are the 2 wires that I circled in Red?

I don't see them on other units.

Looks to me as though someone tried to jump those traces from the underside of the board to the top and connected them improperly.

Not wires, you're seeing the spring on the switch which just happens to coincide with the edges of the area of PCB that's bubbled up.