Author Topic: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR  (Read 13273 times)

0 Members and 1 Guest are viewing this topic.

Online EEVblog

  • Administrator
  • *****
  • Posts: 30597
  • Country: au
    • EEVblog
EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« on: March 27, 2017, 04:00:04 am »
Dave repairs several faults in a 500MHz HP54161B 2GS/s oscilloscope.
One in particular is quite elusive, can you figure it out before Dave does?
BONUS: Sneak peak at a new Siglent SDS1000X-E Series scope!

 
The following users thanked this post: bitwelder, bryanrj1, 1Ghz, MK14

Offline NiHaoMike

  • Super Contributor
  • ***
  • Posts: 5832
  • Country: us
  • "Don't turn it on - Take it apart!"
    • Facebook Page
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #1 on: March 27, 2017, 05:24:45 am »
For the cracked ASIC, try supergluing the piece back on and using conductive ink to hopefully reconnect the traces. Not much to lose trying.
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Cryptocurrency lesson 0: Altcoins and Bitcoin are not the same thing.
 

Offline MK14

  • Super Contributor
  • ***
  • Posts: 2152
  • Country: gb
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #2 on: March 27, 2017, 05:25:01 am »
Thanks, I enjoyed that  :)

Who is Bill, at around 37 min in ?
Presumably he is just playing your arcade game thing.

I saw the cracked PCB, in the first few seconds or so of the video, and expected that to be the problem. The cracked case gives further clues (as you said). I also wonder if the hard knock/drop (presumably) which caused the damage, also cracked the hybrid IC.

It is bit annoying that the calibration? data memory, has got a limited battery (life age). Pity it was not flash/EEPROM used to store the information. But that has a limited time life spec as well. But I expect it can last a lot longer than batteries. E.g. 20 years or longer.
« Last Edit: March 27, 2017, 05:26:41 am by MK14 »
 

Offline apelly

  • Supporter
  • ****
  • Posts: 1037
  • Country: nz
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #3 on: March 27, 2017, 07:16:15 am »
Nicely done!

Now crack the hybrid and give us a look :)
I'd rather a Google clue, link, or some theory than "do this" (generally)
 

Offline bktemp

  • Super Contributor
  • ***
  • Posts: 1623
  • Country: de
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #4 on: March 27, 2017, 07:34:56 am »
It looks like the 3 broken pins on the ASIC are the analogue input (GND, signal, GND). So any repair is probably going to affect the measured signal waveform unless it is done really well.

The lost calibration data probably don't care much, since you need to do a calibration anyway after replacing the ADC ASIC.
It is probably a good idea to also replace the battery backed up SRAM module, since its calibration data has been reset to defaults.

Are the cut/drilled traces on the front pcb because of the gold plating? If I remember correctly it was necessary to connect all traces on a pcb together for electroplating before they changed to electroless plating in recent years.
 
The following users thanked this post: Paul Moir, thm_w

Online tautech

  • Super Contributor
  • ***
  • Posts: 17032
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #5 on: March 27, 2017, 07:41:13 am »
Good watch Dave, just as MK14 has said the broken bezel on the front panel is a big red flag that it's taken a substantial knock.  :(

As much I enjoyed the diagnostics so often faults are easy to find with close inspection. As you have pointed out the PCB was not well fixed, if it had been, maybe the damage might have been more extensive and obvious.
Nice repair, thanks for sharing.  :-+

Won't ask what you thought of the X-E, you'll share that with us in good time.
Avid Rabid Hobbyist
 

Online coppice

  • Super Contributor
  • ***
  • Posts: 5024
  • Country: gb
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #6 on: March 27, 2017, 08:43:30 am »
Can we take it there is no longer going to be an interesting inexpensive scope from Siglent in the near future?
 

Online EEVblog

  • Administrator
  • *****
  • Posts: 30597
  • Country: au
    • EEVblog
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #7 on: March 27, 2017, 09:00:16 am »
For the cracked ASIC, try supergluing the piece back on and using conductive ink to hopefully reconnect the traces. Not much to lose trying.

The traces are cracked right on the corner of the ceramic top cover, so nothing to reconnect to.
 

Online EEVblog

  • Administrator
  • *****
  • Posts: 30597
  • Country: au
    • EEVblog
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #8 on: March 27, 2017, 09:01:54 am »
Are the cut/drilled traces on the front pcb because of the gold plating? If I remember correctly it was necessary to connect all traces on a pcb together for electroplating before they changed to electroless plating in recent years.

Ah, yes, could well be.
 

Online EEVblog

  • Administrator
  • *****
  • Posts: 30597
  • Country: au
    • EEVblog
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #9 on: March 27, 2017, 09:02:43 am »
Can we take it there is no longer going to be an interesting inexpensive scope from Siglent in the near future?

No you shouldn't!
It will set a new benchmark for bang-per-bandwidth.
 

Online EEVblog

  • Administrator
  • *****
  • Posts: 30597
  • Country: au
    • EEVblog
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #10 on: March 27, 2017, 09:05:14 am »
Good watch Dave, just as MK14 has said the broken bezel on the front panel is a big red flag that it's taken a substantial knock.  :(
As much I enjoyed the diagnostics so often faults are easy to find with close inspection. A

I did do that, just not well enough, I missed it the first time. Oh well.

Quote
Won't ask what you thought of the X-E, you'll share that with us in good time.

Very nice bang-per-buck.
 

Offline Windfall

  • Contributor
  • Posts: 30
  • Country: nl
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #11 on: March 27, 2017, 11:57:58 am »
Repairs rock. Good to see something old but worthwhile working again, instead of being dumped.

Not sure though why early on a commonality was apparent (buttons sharing a matrix line), but this commonality was not researched until much later. Also, why the hell did manufacturers still use battery backed RAM for calibration data in 2000, why not use an EEPROM ? I don't get that, unless they wanted it to become useless after X years.
« Last Edit: March 27, 2017, 11:59:37 am by Windfall »
 

Offline technix

  • Super Contributor
  • ***
  • Posts: 3292
  • Country: cn
  • From Shanghai With Love
    • My Untitled Blog
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #12 on: March 27, 2017, 02:20:28 pm »
I wonder if Dave is willing to sell that unit. It still makes a good mid-tier hobbyist DSO after the repair and a new front-end ASIC. And since the calibration RAM data is gone anyway you might as well suck the RTC chip off and replace it with a socketed one. Socketed for easier future servicing as the RTC can just be pulled off the board by hand.
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10406
  • Country: 00
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #13 on: March 27, 2017, 03:15:39 pm »
I wonder if Dave is willing to sell that unit.

I suspect Dave didn't pay much for it.  :popcorn:

 

Offline skycarl

  • Newbie
  • Posts: 3
  • Country: us
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #14 on: March 27, 2017, 03:46:15 pm »
That was a great repair. I too was wondering if the break on the ASIC could somehow be glued but probably not.
Anyway,,, enjoyed this one for sure.
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10406
  • Country: 00
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #15 on: March 27, 2017, 04:39:14 pm »
Dave: Was the chip broken by the 'scope being dropped or did you do something ham-fisted?  :popcorn:
« Last Edit: March 27, 2017, 04:43:17 pm by Fungus »
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10406
  • Country: 00
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #16 on: March 27, 2017, 04:44:36 pm »
For the cracked ASIC, try supergluing the piece back on and using conductive ink to hopefully reconnect the traces. Not much to lose trying.

The traces are cracked right on the corner of the ceramic top cover, so nothing to reconnect to.

I dare say there's somebody out there who could do it but we're only mortal.  :popcorn:
 

Offline MK14

  • Super Contributor
  • ***
  • Posts: 2152
  • Country: gb
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #17 on: March 27, 2017, 04:54:50 pm »
Good watch Dave, just as MK14 has said the broken bezel on the front panel is a big red flag that it's taken a substantial knock.  :(
As much I enjoyed the diagnostics so often faults are easy to find with close inspection. A

I did do that, just not well enough, I missed it the first time. Oh well.

I did have some help though.
I need to get the first "inch" or so of the youtube progress bar, video loaded, so that I can reliably and smoothly watch it in full 1024 HD resolution.

While I was doing that, I was watching the first 30 seconds (approx) two or more times.

So with Dave very early on saying something like, "Watch out viewers, see if you can spot the fault".
So I was pre-warned that it is likely to be observable on the PCB.
I saw a brief image, where I could apparently see crack(s) in the PCB, near the rotary controls.

The cases (HP) are usually rather well built. So it probably would have taken quite a knocking (or drop), to get the damage to the case.

I thought that Dave did very well repairing it.
« Last Edit: March 27, 2017, 05:03:09 pm by MK14 »
 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 10406
  • Country: 00
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #18 on: March 27, 2017, 04:58:15 pm »
What's the explanation for having this trace on the board if it goes nowhere?


 

Online MarkL

  • Supporter
  • ****
  • Posts: 1575
  • Country: us
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #19 on: March 27, 2017, 05:48:13 pm »
The 1NB7-8353 ADC hybrid is also used in the HP 16534A scope card in their modular logic analyzer line.  I recently repaired a couple of them and one had a bad hybrid.

Of course I couldn't resist taking the top off.  Photo below.  I cracked the substrate in the process and also had to use quite a bit of heat.  Some of the caps might have reflowed and shifted a bit.

You can clearly see the ADC on the right and the 32k circular buffer memory on the left.  Someone already pointed out the piece that cracked off on Dave's was the input transmission line which you can see here goes directly to the ADC.


I bought a couple of ADC replacements from the $45 guy on ebay, watronics.  He's a retired HP/Agilent scope engineer and a nice guy.  No affiliation; just a satisfied customer.
 
The following users thanked this post: edavid, Fungus, harrimansat, Muxr, MK14, Andrew McNamara

Offline technix

  • Super Contributor
  • ***
  • Posts: 3292
  • Country: cn
  • From Shanghai With Love
    • My Untitled Blog
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #20 on: March 27, 2017, 06:13:56 pm »
The 1NB7-8353 ADC hybrid is also used in the HP 16534A scope card in their modular logic analyzer line.  I recently repaired a couple of them and one had a bad hybrid.

Of course I couldn't resist taking the top off.  Photo below.  I cracked the substrate in the process and also had to use quite a bit of heat.  Some of the caps might have reflowed and shifted a bit.

You can clearly see the ADC on the right and the 32k circular buffer memory on the left.  Someone already pointed out the piece that cracked off on Dave's was the input transmission line which you can see here goes directly to the ADC.


I bought a couple of ADC replacements from the $45 guy on ebay, watronics.  He's a retired HP/Agilent scope engineer and a nice guy.  No affiliation; just a satisfied customer.
I wonder if there is any way to build an equivalent circuit using modern parts on the same footprint with FR4 substrate material?
 

Offline bittumbler

  • Contributor
  • Posts: 10
  • Country: de
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #21 on: March 27, 2017, 06:23:15 pm »
Hi Dave,

is this one of the models with the Space Invaders easter egg?
 

Offline Paul Moir

  • Frequent Contributor
  • **
  • Posts: 875
  • Country: ca
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #22 on: March 27, 2017, 08:04:18 pm »
What's the explanation for having this trace on the board if it goes nowhere?
Bottom of Reply #4 by bktemp .  I've had always wondered about those on keypads.
 

Offline EvilGeniusSkis

  • Regular Contributor
  • *
  • Posts: 119
  • Country: ca
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #23 on: March 27, 2017, 10:12:02 pm »
It might be worth gluing the piece back on and seeing if you can get solder to wick in and make the connection. It's already broken doesn't matter if you make it worse.
 

Offline snoopy

  • Frequent Contributor
  • **
  • Posts: 648
  • Country: au
    • Analog Precision
Re: EEVblog #982 - HP54616B 500MHz Oscilloscope REPAIR
« Reply #24 on: March 28, 2017, 12:26:33 am »
The 1NB7-8353 ADC hybrid is also used in the HP 16534A scope card in their modular logic analyzer line.  I recently repaired a couple of them and one had a bad hybrid.

Of course I couldn't resist taking the top off.  Photo below.  I cracked the substrate in the process and also had to use quite a bit of heat.  Some of the caps might have reflowed and shifted a bit.

You can clearly see the ADC on the right and the 32k circular buffer memory on the left.  Someone already pointed out the piece that cracked off on Dave's was the input transmission line which you can see here goes directly to the ADC.


I bought a couple of ADC replacements from the $45 guy on ebay, watronics.  He's a retired HP/Agilent scope engineer and a nice guy.  No affiliation; just a satisfied customer.
I wonder if there is any way to build an equivalent circuit using modern parts on the same footprint with FR4 substrate material?

Probably no which is why the low end scope manufacturers have not been able to offer something economical in the 500 MHz and above category ;)
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf