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  1. HP-Agilent-Keysight-Equipment
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8340A Fault - ADC

 

Hi there,

I am looking into buying a 8340A with known problem — Fault light on, fault code ADC. From the service manual, it says ADC fault indicates CPU detected ADC circuit problem on A27 level control assembly. When ADC is faulting, SYTM won’t track and won’t peak.

However, the manual has very little information on A27 troubleshooting. What would have caused the ADC fault? How does the power-on-self-test determine the ADC circuit is bad? Could it be as simple as bad reference voltage on the ADC or something very involved?

Thank you!
Calvin
 

Fault could be either the ADC chip or the signals controlling it. I
believe the 8340 permits direct control of the peripheral boards.
Diagnostic procedure would be to measure value at ADC input and look at
corresponding digital; values. You could pull eht ADC chip or try to run
the board in a home made test jig. Additionally, as I remember, there are
some board specific diagnostics that you can invoke.

Look over the board schematic and decide how best to attack the problem -
probably not the digital control signals as other boards using the same
control signals working (?).

Hi there,

I am looking into buying a 8340A with known problem — Fault light on,
fault code ADC. From the service manual, it says ADC fault indicates CPU
detected ADC circuit problem on A27 level control assembly. When ADC is
faulting, SYTM won’t track and won’t peak.

However, the manual has very little information on A27 troubleshooting.
What would have caused the ADC fault? How does the power-on-self-test
determine the ADC circuit is bad? Could it be as simple as bad reference
voltage on the ADC or something very involved?

Thank you!
Calvin
 

Hello,

It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.?I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue??It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:?

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
?
 

开云体育

Hi Lex,

Yes, it’s ADC fault. The instrument has Fault annunciator lit. I asked the guy to press [shift][manual], and the ADC lights are blinking the the Entry Display. The other faults that would turn on the Fault annunciator are PEAK, TRACK, KICK, and CAL. Although the PEAK and TRK aren’t not blinking, I don’t know if they are also fault as ADC failure may automatically disable PEAK and TRACK.?

I read the 8340B A27 assembly schematic from keysight. Unfortunately, the ADC Clock control and input MUX part is mostly messed up, but the ADC chip itself seems very simple.The 8341A service manual schematic is not humanly readable.

Good thing about it is there are no other abnormal annunciator are lit. UNLEVELED is off, UNLOCK is off. My gut feels it’s something simple but I could be totally wrong.

If the store owner is nice enough, I *might* be able to visit the him to see the instrument in person. What basic tests would you suggest me to run?

Thanks,
Calvin

On Oct 22, 2017, at 5:38 PM, lexternegron@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Hello,


It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.?I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue??It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:?

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
?
 

开云体育

Hi Calvin

I have the complete 8340A service manuals in paper on my desk. I try to find someone who can scan these plus size pages. My scanner at home or in the office can't do that.
Unfortunately, there are no human readable schematics available on the net. I wonder what those guys think when they upload such crappy documents - its absolutely pointless if the schematics are unreadable :-)
Anyway, I can not yet scan the whole thing, but I can make some (readable!) photographs of the A27 schematics if you like.

If you can run another self test on the unit, please do [shift][ext] which shows whether all PLLs are locked. As long as the oven is cold, REF will be flashing, which is okay, it will go away as soon as the oven has reached temperature after about 5min. The oven annunciator should be off. All other PLLs should be locked. If the YO is unlocked.... well, from my repair project you probably know that one can be lucky and the YO can be repaired, but if the YO is blown it can be messy.

If the unit is not too expensive I would go for it. ADC seems to me like a problem which should be repairable (and even if the YO is blown it would be an interesting project to fit another YO, the original 0586-7323 seems unobtanium... :-)).

I once had a 4195A where a? DAC chip had a crack and thus an internal bond junction went bad, leading to the error that the DAC was working in principle, but one single bit was not working. I hat to replace the DAC, which is still manufactured today, so it was easy to obtain a replacement. I would not be surprised if the same was true with the ADC you have problems with.

Tobias HB9FSX



-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 04:39 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

Hi Lex,


Yes, it’s ADC fault. The instrument has Fault annunciator lit. I asked the guy to press [shift][manual], and the ADC lights are blinking the the Entry Display. The other faults that would turn on the Fault annunciator are PEAK, TRACK, KICK, and CAL. Although the PEAK and TRK aren’t not blinking, I don’t know if they are also fault as ADC failure may automatically disable PEAK and TRACK.?

I read the 8340B A27 assembly schematic from keysight. Unfortunately, the ADC Clock control and input MUX part is mostly messed up, but the ADC chip itself seems very simple.The 8341A service manual schematic is not humanly readable.

Good thing about it is there are no other abnormal annunciator are lit. UNLEVELED is off, UNLOCK is off. My gut feels it’s something simple but I could be totally wrong.

If the store owner is nice enough, I *might* be able to visit the him to see the instrument in person. What basic tests would you suggest me to run?

Thanks,
Calvin

On Oct 22, 2017, at 5:38 PM, lexternegron@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Hello,


It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.?I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue??It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:?

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
?
 

开云体育

Hi Calvin

I checked the A27 parts list. Following chips seem to be used:

NE5018F DAC - can be found on eBay

1826-0881 ADC - this is actually an ADC856C. I am unsure whether this can be replaced easily, but I only searched for approx. 5min :-)

MP7533MP - a pin compatible replacement from Maxim is available, called MX7533. Should be available at the usual distributors (Mouser, Digikey, whatever).

Best
Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 04:39 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

Hi Lex,


Yes, it’s ADC fault. The instrument has Fault annunciator lit. I asked the guy to press [shift][manual], and the ADC lights are blinking the the Entry Display. The other faults that would turn on the Fault annunciator are PEAK, TRACK, KICK, and CAL. Although the PEAK and TRK aren’t not blinking, I don’t know if they are also fault as ADC failure may automatically disable PEAK and TRACK.?

I read the 8340B A27 assembly schematic from keysight. Unfortunately, the ADC Clock control and input MUX part is mostly messed up, but the ADC chip itself seems very simple.The 8341A service manual schematic is not humanly readable.

Good thing about it is there are no other abnormal annunciator are lit. UNLEVELED is off, UNLOCK is off. My gut feels it’s something simple but I could be totally wrong.

If the store owner is nice enough, I *might* be able to visit the him to see the instrument in person. What basic tests would you suggest me to run?

Thanks,
Calvin

On Oct 22, 2017, at 5:38 PM, lexternegron@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Hello,


It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.?I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue??It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:?

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
?
 

开云体育

I also googled but a minute or two.


What is the housing of that ADC IS? Worst case, one can IMHO grab an SMD part and make a fourlayer adapter at the usual PCB making suspects


On 23.10.2017 07:13, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:

???

Hi Calvin


I checked the A27 parts list. Following chips seem to be used:

NE5018F DAC - can be found on eBay

1826-0881 ADC - this is actually an ADC856C. I am unsure whether this can be replaced easily, but I only searched for approx. 5min :-)

MP7533MP - a pin compatible replacement from Maxim is available, called MX7533. Should be available at the usual distributors (Mouser, Digikey, whatever).

Best
Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 04:39 (GMT+01:00)
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

???

Hi Lex,


Yes, it???s ADC fault. The instrument has Fault annunciator lit. I asked the guy to press [shift][manual], and the ADC lights are blinking the the Entry Display. The other faults that would turn on the Fault annunciator are PEAK, TRACK, KICK, and CAL. Although the PEAK and TRK aren???t not blinking, I don???t know if they are also fault as ADC failure may automatically disable PEAK and TRACK.???

I read the 8340B A27 assembly schematic from keysight. Unfortunately, the ADC Clock control and input MUX part is mostly messed up, but the ADC chip itself seems very simple.The 8341A service manual schematic is not humanly readable.

Good thing about it is there are no other abnormal annunciator are lit. UNLEVELED is off, UNLOCK is off. My gut feels it???s something simple but I could be totally wrong.

If the store owner is nice enough, I *might* be able to visit the him to see the instrument in person. What basic tests would you suggest me to run?

Thanks,
Calvin

On Oct 22, 2017, at 5:38 PM, lexternegron@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Hello,


It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.???I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue????It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:???

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
???
 

开云体育

The ADC is in a wide DIP (don't know the dimensions from heart, but it has the same width as an ordinary EPROM).



-------- Original message --------
From: "Tam Hanna tamhan@... [hp_agilent_equipment]"
Date: 10/23/17 07:52 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

I also googled but a minute or two.


What is the housing of that ADC IS? Worst case, one can IMHO grab an SMD part and make a fourlayer adapter at the usual PCB making suspects


On 23.10.2017 07:13, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:
?

Hi Calvin


I checked the A27 parts list. Following chips seem to be used:

NE5018F DAC - can be found on eBay

1826-0881 ADC - this is actually an ADC856C. I am unsure whether this can be replaced easily, but I only searched for approx. 5min :-)

MP7533MP - a pin compatible replacement from Maxim is available, called MX7533. Should be available at the usual distributors (Mouser, Digikey, whatever).

Best
Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 04:39 (GMT+01:00)
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

Hi Lex,


Yes, it’s ADC fault. The instrument has Fault annunciator lit. I asked the guy to press [shift][manual], and the ADC lights are blinking the the Entry Display. The other faults that would turn on the Fault annunciator are PEAK, TRACK, KICK, and CAL. Although the PEAK and TRK aren’t not blinking, I don’t know if they are also fault as ADC failure may automatically disable PEAK and TRACK.?

I read the 8340B A27 assembly schematic from keysight. Unfortunately, the ADC Clock control and input MUX part is mostly messed up, but the ADC chip itself seems very simple.The 8341A service manual schematic is not humanly readable.

Good thing about it is there are no other abnormal annunciator are lit. UNLEVELED is off, UNLOCK is off. My gut feels it’s something simple but I could be totally wrong.

If the store owner is nice enough, I *might* be able to visit the him to see the instrument in person. What basic tests would you suggest me to run?

Thanks,
Calvin

On Oct 22, 2017, at 5:38 PM, lexternegron@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Hello,


It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.?I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue??It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:?

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
?
 

Rapes and Stinks, no?

Now all we need is someone to undig the datasheet. The moment we have that, we can slink something together with ease.

I dont want to promise anything as my life currently is a bit topsy turvy and I am already caught up in projects...but if you need help, I am willing to take a look at the Design and help out. If you cant solder SMD, I might be able to help too.
---
With best regards
Tam HANNA (emailing on a BlackBerry PRIV)

Enjoy electronics? Join 6500 other followers by visiting the Crazy Electronics Lab at

Am 23. Oktober 2017 08:34:59 MESZ schrieb "Tobias Pluess tobias.pluess@... [hp_agilent_equipment]" :

?

The ADC is in a wide DIP (don't know the dimensions from heart, but it has the same width as an ordinary EPROM).




-------- Original message --------
From: "Tam Hanna tamhan@... [hp_agilent_equipment]"
Date: 10/23/17 07:52 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

I also googled but a minute or two.


What is the housing of that ADC IS? Worst case, one can IMHO grab an SMD part and make a fourlayer adapter at the usual PCB making suspects


On 23.10.2017 07:13, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:
?

Hi Calvin


I checked the A27 parts list. Following chips seem to be used:

NE5018F DAC - can be found on eBay

1826-0881 ADC - this is actually an ADC856C. I am unsure whether this can be replaced easily, but I only searched for approx. 5min :-)

MP7533MP - a pin compatible replacement from Maxim is available, called MX7533. Should be available at the usual distributors (Mouser, Digikey, whatever).

Best
Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 04:39 (GMT+01:00)
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

Hi Lex,


Yes, it’s ADC fault. The instrument has Fault annunciator lit. I asked the guy to press [shift][manual], and the ADC lights are blinking the the Entry Display. The other faults that would turn on the Fault annunciator are PEAK, TRACK, KICK, and CAL. Although the PEAK and TRK aren’t not blinking, I don’t know if they are also fault as ADC failure may automatically disable PEAK and TRACK.?

I read the 8340B A27 assembly schematic from keysight. Unfortunately, the ADC Clock control and input MUX part is mostly messed up, but the ADC chip itself seems very simple.The 8341A service manual schematic is not humanly readable.

Good thing about it is there are no other abnormal annunciator are lit. UNLEVELED is off, UNLOCK is off. My gut feels it’s something simple but I could be totally wrong.

If the store owner is nice enough, I *might* be able to visit the him to see the instrument in person. What basic tests would you suggest me to run?

Thanks,
Calvin

On Oct 22, 2017, at 5:38 PM, lexternegron@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Hello,


It depends on who you're buying from. Personally I would go for it if I knew the basic diagnostic self tests were working, the seller isn't selling a physically damaged unit and if I had the money.?I have to ask though. Did you mean ALC? There is no fault light indicator for ADC. Possible scratch or sticker residue??It can be anything from a faulty reference to something as serious as the RF module(s) for the ALC section.

I have the manuals but it would be a written essay on here explaining or posting pics of everything in detail. Check all manual paperwork from Keysight. Its all there but everything is imho mislabeled. Search for all 8340/1/A/B models (4 models in total). This also sounds similar but may not be the same problem as another member here had.

Link to another faulty unit:?

All in all I would need further information obtained from diagnostic tests. Also its ultimately up to you but as I said, I personally would buy it and accept whatever consequences I may receive.

-Lex
?
 

Hello Calvin,

I see. Sorry about the mix up. Just want to make sure. The basic tests are [Shift + Free run], [Shift + Manual] (done), and [Shift + M4].

[Shift + Free run]?is for the lighting and is to make sure all LEDs light up like Christmas. It also indirectly tests the processing side by noting that the correct behavior of the marching pattern as described in the manual. You've pressed [Shift + Manual]?for the fault annuciator already so we know to focus on the ADC. As for [Shift + M4], I don't think it'll be of any help but you can try. Actually I forget what it will do with an ADC fault. Its a diagnostic test that tests everything and will list everything. The thing to note here is that an ADC is higher in the chain vs individual components tethered to sections of the rf path. The Processing section being the highest in the chain.

You're right that 8340B schematic is literally broken and 8340A (assuming this since they don't have a 8341A) is unreadable but did you try all of the manuals? 8340A 8341A 8340B and 8341B are all the same except for FM input, SYTM for 20GHz vs 26.5GHz, and a sweep output 5 vs 10 V/GHz. I do admit it is still hard to read but I've seen harder. 8673B + 8673C/D service manuals were insane before I found a recent independent scan via google search and this group. Here is a link for 8341B component level volume. (page 201)

?

Be sure to read up on theory of operation for A27 in the assembly level volume as well. A21 is involved based on the RF block diagram. What its doing and how it affects A27 that would have to be read. I see "ADC timing"
as the name of the signal between those boards.

If worse comes to worse there is google and bitsavers for individual component catalog/product guide searches (ie. motorola, nec, pmi, national semiconductor).??or ebay at the assembly level.

So far it looks good in terms of economical repair. Anything encased in a solid block of metal that is damaged on the RF path is expensive. Can still be repairable within economical means as shown by Tobias' recent post. That was really lucky though imo. If the damage was on a hybrid circuit (ie bond wire or MMIC amp, transistor, diode)..... uneconomically repairable. It can still be repaired but you'd need to be in the business of wire bonding and Microwave IC design or negotiate the replacement assembly's the price down. Prices can be negotiated down if you know if the component is used in another instrument. HP usually repurposes the same components in different equipment. An example is a hybrid circuit I thought I was doomed to be unobtainium. Turns out this circuit is used in 3 instruments. What would have been a $600 - $1500 part was negotiated down to $175. Probably lower with the way things are trending. Checking now, there is a seller selling more than 10 but doesn't know what they have. There is another seller also selling extra components along with the component of interest for half of what the lone assembly would go for. Anyways I don't believe you will have this problem or those types of hoops and hurdles. I suspect a few components on a board assembly or 2 is the issue that failed due to old age. ICs or capacitors that age with heat, cycle use, and naturally occurring chemistry (oxides and acids forming). Compare that to someone that put in too strong of a signal and blew the inputs of the AM and PM. Worse would be the RF output (that attenuator and other RF modules are not cheap) or a physical drop of the instrument or on top of the instrument due to moving. Good luck with your potential buy.

-Lex
 

From googling, hp crosref (link??), and bitsavers. Might have to Ctrl + F part of the name like I did for "DC856" since pdf file have a hard time reading.

Signetics Corp. NE5018F - page 550



Datel Systems Inc. or Datel-Intersil ADC856C - page 145



Micro Power Systems (owned by the Exar Corporation) MP7533MP - page ???

??? need to find this. I thought the Datel one with the custom HP number would be hard.

and one more, the MUX

Precision Monolithic Inc. - page 764



These are a fountain of knowledge. Now only specs but app notes and introductions as to why to use them in design. Enjoy.

-Lex
 

开云体育

Lex,
the MP7533 is the easiest. Didn't you see my previous message?
It is the same as MX7533 by Maxim, still available :-)

Tobias





-------- Original message --------
From: "lexternegron@... [hp_agilent_equipment]"
Date: 10/23/17 12:52 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

From googling, hp crosref (link??), and bitsavers. Might have to Ctrl + F part of the name like I did for "DC856" since pdf file have a hard time reading.


Signetics Corp. NE5018F - page 550



Datel Systems Inc. or Datel-Intersil ADC856C - page 145



Micro Power Systems (owned by the Exar Corporation) MP7533MP - page ???

??? need to find this. I thought the Datel one with the custom HP number would be hard.

and one more, the MUX

Precision Monolithic Inc. - page 764



These are a fountain of knowledge. Now only specs but app notes and introductions as to why to use them in design. Enjoy.

-Lex
 

Hello Tobias,

Oops. (facepalms) and I was looking at your post too! (facepalms harder). Confused your post with Tam Hanna. XD That'll do as a replacement. As for the ADC, I concur about availability. I'll have to check later on. The data book posted should be useful in knowing electrical characteristics. As for physical ones, you may have to get creative while looking for a size flexible replacement. Maybe on some of the electrical characteristics as well.

-Lex
 

You guys are awesome!!!
I will carefully read the ADC's datasheet to see if there is any viable substitute for it. My repair stories so far is always in RF and pure analog path. This is certainly a challenge for me given that the part is not readily available. I'll see if I can negotiate a good price with the seller that worth the trouble.

What is the fair price you would offer for a non-defective 8340 if you guys don't mind...

Thanks again!
Calvin

On Monday, October 23, 2017, 4:52:01 AM PDT, lexternegron@... [hp_agilent_equipment] wrote:


?

Hello Tobias,


Oops. (facepalms) and I was looking at your post too! (facepalms harder). Confused your post with Tam Hanna. XD That'll do as a replacement. As for the ADC, I concur about availability. I'll have to check later on. The data book posted should be useful in knowing electrical characteristics. As for physical ones, you may have to get creative while looking for a size flexible replacement. Maybe on some of the electrical characteristics as well.

-Lex
 

开云体育

Hi Calvin
unfortunately, I've got no 8340 to offer. However, I have a large collection of old and obsolete ICs.
If you tell me what you need, I can have a look.
The 7533 is available from Maxim, the other parts I don't know whether I can find one.
I can have a look tomorrow :-)
However, I would first try some more debugging to see whether the fault is somewhere else, and not in the ADCs.


Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 21:09 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

You guys are awesome!!!
I will carefully read the ADC's datasheet to see if there is any viable substitute for it. My repair stories so far is always in RF and pure analog path. This is certainly a challenge for me given that the part is not readily available. I'll see if I can negotiate a good price with the seller that worth the trouble.

What is the fair price you would offer for a non-defective 8340 if you guys don't mind...

Thanks again!
Calvin

On Monday, October 23, 2017, 4:52:01 AM PDT, lexternegron@... [hp_agilent_equipment] wrote:


?

Hello Tobias,


Oops. (facepalms) and I was looking at your post too! (facepalms harder). Confused your post with Tam Hanna. XD That'll do as a replacement. As for the ADC, I concur about availability. I'll have to check later on. The data book posted should be useful in knowing electrical characteristics. As for physical ones, you may have to get creative while looking for a size flexible replacement. Maybe on some of the electrical characteristics as well.

-Lex
 

开云体育

Hi,

if the 5018 is needed, I have some pulls here in good condition.

Regards, Jochen DH6FAZ


Am 23.10.2017 um 21:21 schrieb Tobias Pluess tobias.pluess@... [hp_agilent_equipment]:

???

Hi Calvin

unfortunately, I've got no 8340 to offer. However, I have a large collection of old and obsolete ICs.
If you tell me what you need, I can have a look.
The 7533 is available from Maxim, the other parts I don't know whether I can find one.
I can have a look tomorrow :-)
However, I would first try some more debugging to see whether the fault is somewhere else, and not in the ADCs.


Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 21:09 (GMT+01:00)
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

???
You guys are awesome!!!
I will carefully read the ADC's datasheet to see if there is any viable substitute for it. My repair stories so far is always in RF and pure analog path. This is certainly a challenge for me given that the part is not readily available. I'll see if I can negotiate a good price with the seller that worth the trouble.

What is the fair price you would offer for a non-defective 8340 if you guys don't mind...

Thanks again!
Calvin

On Monday, October 23, 2017, 4:52:01 AM PDT, lexternegron@... [hp_agilent_equipment] wrote:


???

Hello Tobias,


Oops. (facepalms) and I was looking at your post too! (facepalms harder). Confused your post with Tam Hanna. XD That'll do as a replacement. As for the ADC, I concur about availability. I'll have to check later on. The data book posted should be useful in knowing electrical characteristics. As for physical ones, you may have to get creative while looking for a size flexible replacement. Maybe on some of the electrical characteristics as well.

-Lex
 

I read the broken A27 schematic, some ADC sub blocks are overlay on top of other -- what a mess!!!
However some blocks are readable. If I have the instrument, I would first check the ADC clock generator U6B and particular the RC feedback network C32 and R21. Don't know what type of cap C32 is. If it's a electrolytic, it may just be leaking causing it not to oscillate therefore no clock to ADC.

Calvin


On Monday, October 23, 2017, 12:21:27 PM PDT, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:


?

Hi Calvin

unfortunately, I've got no 8340 to offer. However, I have a large collection of old and obsolete ICs.
If you tell me what you need, I can have a look.
The 7533 is available from Maxim, the other parts I don't know whether I can find one.
I can have a look tomorrow :-)
However, I would first try some more debugging to see whether the fault is somewhere else, and not in the ADCs.


Tobias


-------- Original message --------
From: "Calvin Guan guancalvin@... [hp_agilent_equipment]"
Date: 10/23/17 21:09 (GMT+01:00)
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Re: 8340A Fault - ADC

?

You guys are awesome!!!
I will carefully read the ADC's datasheet to see if there is any viable substitute for it. My repair stories so far is always in RF and pure analog path. This is certainly a challenge for me given that the part is not readily available. I'll see if I can negotiate a good price with the seller that worth the trouble.

What is the fair price you would offer for a non-defective 8340 if you guys don't mind...

Thanks again!
Calvin

On Monday, October 23, 2017, 4:52:01 AM PDT, lexternegron@... [hp_agilent_equipment] wrote:


?

Hello Tobias,


Oops. (facepalms) and I was looking at your post too! (facepalms harder). Confused your post with Tam Hanna. XD That'll do as a replacement. As for the ADC, I concur about availability. I'll have to check later on. The data book posted should be useful in knowing electrical characteristics. As for physical ones, you may have to get creative while looking for a size flexible replacement. Maybe on some of the electrical characteristics as well.

-Lex

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