Agilent 54835A scope (4 channel 1GHz / 4Gs/s) repair & uphack

[lukier]

Why not build one like this one : https://elektrotanya.com/files/forum/2009/10/e04a036.pdf 

But put it in an aluminium tube or buy one like this one : http://www.benl.ebay.be/itm/RF-Active-Probe-0-1-1500-MHz-1-5-GHz-analyzer-oscilloscope/332253695460?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

I remember reading threads here about these probes, even wanted to DIY something, but then I scored multiple (single/diff) LeCroy active probes for a decent price. What stuck to me is that all these DIY designs are "RF" probes and AC coupled (no DC) and I wondered if this could be a problem.

[Howardlong]

My scope is now 100% OK and update to the latest version. 

Now the probe problem, I have 1 new 1161A supplied with the scope, maybe I’ll try to get another one on a “decent” price but need to come from Europe since shipping and duty make it not affordable in comparison to the investment of the scope. 

I will maybe buy 2 or 4 200mhz probes from Hantek, they are not expensive. 

Now why having a 1.5ghz scope and not having the appropriate probes? 

They are too expensive, 500-800€ and more + shipping cost + duty’s for 1 probe! 

Why not build one like this one : https://elektrotanya.com/files/forum/2009/10/e04a036.pdf 

But put it in an aluminium tube or buy one like this one : http://www.benl.ebay.be/itm/RF-Active-Probe-0-1-1500-MHz-1-5-GHz-analyzer-oscilloscope/332253695460?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

It should be possible to get power from the autoprobe, I could manage to build a BNC connector with a pin to get the right voltage needed for this kind of probe. 

Anybody experience in this area?

The 1152A 2.5GHz 100k ohm 0.6pF FET probe is frequently available for a reasonable price, but just make sure it comes with a good set of the accessory parts, particularly the walking stick ground seems to go amiss. You can survive without it by jury rigging your solution but it's not best solution.

Also the 54006a 10:1 & 20:1 (500 and 1k ohm) 0.25pF 6GHz resistive passive probe, again make sure it comes with accessories including the walking stick probe assemblies, spare resistors, AC coupler, SMA cable and the SMA-BNC adapter.

Plus...
N2874A 10:1 1.5GHz resistive (500 ohm) 2pF passive probe.
N2876A 100:1 1.5GHz resistive (5k ohm) 2.5pF passive probe.

[nctnico]

I tried to install XP but the problem is that the drivers for the acquisition card are not available. The Windows98 drivers won't work on XP because XP is completely different when it comes to drivers.

Do you know what the VIDs/PIDs are for the acq card? Maybe in the range 15BC:0500 to 15BC:0507?

No, according to the list from the BIOS I think it is 103C:1020 (that is the only unknown PCI device listed)

[JanNousiainen]

Welp, mine is out of commission again I tried to update SW from HDD but setup quit before end because I had IE3, not IE4... Now scope loader just freezes.

I guess I will be getting few IDE HDD's and CD-ROM and start from scratch.

Managed to get Win 95 and Win 7 machines to see eachother in network but could not log in to shares from either one. So I set up a http server in Win7 and downloaded update SW to scope that way.

[Neganur]

You should be able to just hook the HDD to your win7 machine and access the files directly.

[JanNousiainen]

You should be able to just hook the HDD to your win7 machine and access the files directly.

None of the machines I have at hand have IDE bus, only SATA. I do have older machines with IDE but they are about 1000 km away...

USB to IDE adapter would work. I have one of those but you guessed it, it is also somewhere else. I'll check if I can get cheap one locally.

[eurofox]

You should be able to just hook the HDD to your win7 machine and access the files directly.

None of the machines I have at hand have IDE bus, only SATA. I do have older machines with IDE but they are about 1000 km away...

USB to IDE adapter would work. I have one of those but you guessed it, it is also somewhere else. I'll check if I can get cheap one locally.

I have since several years a device that connect USB to all common hard disk technology, ATA, SATA, IDE ….
I don’t remember the price I pay for it but it was quite cheap.



I’m surprised that you got problems to transfer the updates over the network.
I reinstall de driver for network card, enable Microsoft client with TCPIP and allow disk sharing without password.
On my Windows 10 notebook I make “discovery of network” active, the scope was discovered and provide access to the hard disk of the scope and this ways I could transfer the update files.

[eurofox]

My scope is now 100% OK and update to the latest version. 

Now the probe problem, I have 1 new 1161A supplied with the scope, maybe I’ll try to get another one on a “decent” price but need to come from Europe since shipping and duty make it not affordable in comparison to the investment of the scope. 

I will maybe buy 2 or 4 200mhz probes from Hantek, they are not expensive. 

Now why having a 1.5ghz scope and not having the appropriate probes? 

They are too expensive, 500-800€ and more + shipping cost + duty’s for 1 probe! 

Why not build one like this one : https://elektrotanya.com/files/forum/2009/10/e04a036.pdf 

But put it in an aluminium tube or buy one like this one : http://www.benl.ebay.be/itm/RF-Active-Probe-0-1-1500-MHz-1-5-GHz-analyzer-oscilloscope/332253695460?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

It should be possible to get power from the autoprobe, I could manage to build a BNC connector with a pin to get the right voltage needed for this kind of probe. 

Anybody experience in this area?

The 1152A 2.5GHz 100k ohm 0.6pF FET probe is frequently available for a reasonable price, but just make sure it comes with a good set of the accessory parts, particularly the walking stick ground seems to go amiss. You can survive without it by jury rigging your solution but it's not best solution.

Also the 54006a 10:1 & 20:1 (500 and 1k ohm) 0.25pF 6GHz resistive passive probe, again make sure it comes with accessories including the walking stick probe assemblies, spare resistors, AC coupler, SMA cable and the SMA-BNC adapter.

Plus...
N2874A 10:1 1.5GHz resistive (500 ohm) 2pF passive probe.
N2876A 100:1 1.5GHz resistive (5k ohm) 2.5pF passive probe.

The 1152A with accessories go for more than what I pay for the not working scope.

On the top of that they are usually available on the US market, this mean a lot of shipping cost and import duties.

This is the classical problem when you buy a second and high bandwidth scope, the probes cost are equal or superior of the scope itself because on the second hand market, a working probe is sold from 25% to 50% of the a new one, the scope is from 5% (not working) to 25% for a working one.

[JanNousiainen]

Bought USB -> IDE / SATA adapter with power supply for drive and 2 x 40 GB IDE HDD for 25€, now I have to wait for them to arrive from china...

[Someone]

The 1152A with accessories go for more than what I pay for the not working scope.

On the top of that they are usually available on the US market, this mean a lot of shipping cost and import duties.

This is the classical problem when you buy a second and high bandwidth scope, the probes cost are equal or superior of the scope itself because on the second hand market, a working probe is sold from 25% to 50% of the a new one, the scope is from 5% (not working) to 25% for a working one.

Even for a new scope its normal to spend equal to or more than the purchase price on probes. If you're stuck with your mindset of cheap broken scopes for repairs then you should buy broken probes and repair them to go with it.

[eurofox]

I wake up this thread with respect to USB on the scope.

According the experience of ntcnico, it seems that removing the floppy create some problem, it is a pity because usb floppy slim emulator are available and they are cheap. 

Other solution since I think there is one PCI slot free on the motherboard is installing a PCI USB adapter with support for Win98, they are available on ebay second hand for a few €.

I just checked the rise time from my Infiniium scope, 232ps, this confirm the 1.5GHz bandwidth. 

[eurofox]

Update on my scope:
USB: My motherboard support 2 USB connections on the motherboard.

I bought this unit: http://electromyne.de/Server-Parts-Supermicro-FPUSB813-Server-Front-Panel-2x-USB-Serial-COM-RS232-Silver-Silber.html
Fit perfectly in the place of the original floppy, com port as well on the front.
It is plug & play and no need to pray, cables, screws all fit perfectly, com2 is now connected to the front panel. 

Manage in the bios to disable the floppy and work without problem with the floppy removed. 

I added as well memory, very cheap from the same shop and was shipped in 2 days door to door from Germany. 

Got the exact colour to repair the little scratches and blemish, now my scope is in a real mint condition.

Install a pdf printer emulator. 

Now hunting for probes. 

[Tony_G]

I added as well memory, very cheap from the same shop and was shipped in 2 days door to door from Germany. 

What was the real impact of adding the memory? Was it just faster operation due to less swap file access or did it make the actual scope memory depth better?

TonyG

[Jwalling]

I bought this unit: http://electromyne.de/Server-Parts-Supermicro-FPUSB813-Server-Front-Panel-2x-USB-Serial-COM-RS232-Silver-Silber.html
Fit perfectly in the place of the original floppy, com port as well on the front.
It is plug & play and no need to pray, cables, screws all fit perfectly, com2 is now connected to the front panel. 

Got the exact colour to repair the little scratches and blemish, now my scope is in a real mint condition.

I think that you should paint the USB/COM port the same color as the front panel since you have the paint.

EDIT: PS, nice job though! 

[eurofox]

I added as well memory, very cheap from the same shop and was shipped in 2 days door to door from Germany. 

What was the real impact of adding the memory? Was it just faster operation due to less swap file access or did it make the actual scope memory depth better?

TonyG

On the Infiniium software I don't see any improvement, when using Win98 explorer or other programs it is more reactiv.
 

[Zucca]

Manage in the bios to disable the floppy and work without problem with the floppy removed. 

Is tha an user option in the BIOS or an hack? Can you provide more details?

[eurofox]

Manage in the bios to disable the floppy and work without problem with the floppy removed. 

Is tha an user option in the BIOS or an hack? Can you provide more details?

It is just tricking the setting, not really an hack but not really a setting 

[JanNousiainen]

Ok, made a new clean HDD and installed Windows 98 First Edition to it. Started installing 4.5 scope software to it but after creating RAM drive and rebooting nothing further happens, running the installer gives empty error message dialog. Same with 4.3. Installer packages that I have only contain three files, executable and two other files.

Should I install Win95 instead? That is what the scope came with but it had older scope SW version, started with 3.

[nctnico]

Did you also install the driver for the acquisition board? How do the PCI settings look?

[Tony_G]

I go through the process of installing the software in this video:

https://youtu.be/L49qug1oGuo?t=5m9s

You can get all the files here:

https://1drv.ms/f/s!Amqar8_XQ9Uzj6YhN1xHdM8tQdKMOA

Read the PDF and start with the recovery image. FYI This process requires the use of a CDROM drive, TheSteve published a way around that:

Decided I should try upgrading from version 3.50 today.
As nctnico has already mentioned the built in upgrade tool only wants to read from the Magneto Optical drive. He used a hex editor to change the path so he could read the upgrade files from a USB drive. My scope has no USB ports so I tried something else.
I unpacked the 4_3_upg upgrade package on my desktop and copied the files directly to the scopes hard drive. I then booted the scope, killed the scope app and used explorer to copy the files to c:\scope\upgrade\scope\temp\
Once the files are copied you can run HP548UPG.exe directly from that directory and it will perform the upgrade.
With version 4.3 running I removed all of the files from the upgrade directory and repeated the process with the 4.5 update.
It was a pretty hassle free way to upgrade the scope. Going from version 3.5 to 4.3 easily doubles the boot time of the scope(3.5 direct to 4.5 might not as it will skip the web features). I suppose that is the tradeoff for adding the built in webserver with webcontrol. If nothing else it makes it easy to grab screen shots.

TonyG

[Tony_G]

Any update? Just wondering how it turned out.

[Jwalling]

Back to the uphacking part. I located several resistors and decided to attach some switches after a few futile attempts to change the resistors using SMT tweezers.



The scope software can be stopped using ctrl-alt-del which opens up the task manager on Win98 and restarted from the menu so testing all the combinations could be done quickly.

Code: [Select]

R3 R2 R1 R0
-  -  X  X  54835A
X  X  -  -  54845A

X = placed, - = open

I have not found the 54846A mode but I have not included R4 in my test because I didn't spot it when looking for potential candidates. For now I'm fine with the 54845A mode.

According to the notes I have (and I think I PM'd them to you), there are only two resistors used for strapping. Was I incorrect?

(note that my crappy drawing doesn't show that R1 is also 0 Ohms.)

I have a 54846A on my bench that I'm repairing at the moment (bulging caps on the motherboard). When I get it up and running, I'll pull the ACQ board and verify the config.

When I had the motherboard pulled, I noticed that the date code on the sheet metal under the MB was dated 2001, yet the serial prefix is MY40. How can this be?   I would have thought that the sheet metal should have been older, or the serial # newer...

[Jwalling]

Here's the 54846A. Just two resistors need to be de-populated, so my drawing is at least correct for the 54846A.

[nctnico]

I must say I tested my scope with software version 3.x so maybe that version doesn't support the 54846A  But it is good to know which strapping I need alter in order to unleash more bandwidth 

[Jwalling]

I must say I tested my scope with software version 3.x so maybe that version doesn't support the 54846A  But it is good to know which strapping I need alter in order to unleash more bandwidth 

I'm not sure about that one...

Now that I'm playing with one of these again, I remember one thing I really dislike about them. They won't trigger for shit at anywhere near their rated bandwidth with a sine wave applied. This one craps out at about 1.3GHz, and I'm combining CH1 CH2 for 8GS/s. There was an excuse explanation by an Agilent Keysight support engineer (I think it was Algoss) that I bookmarked, but I guess the link didn't survive a change in their forum. Or maybe they trash the old stuff.
It was here: http://www.keysight.com/owc_discussions/thread.jspa?messageID=118580&#118580

Should have saved it locally