Agilent U1602B DSO Teardown

[threephase]

Some pictures of the insides of U1602B Scope.

Two machine screws hold the battery pack in place and then another 6 machine screws hold the back half of the case to the front. None of these screws were found to be captive within the case. The back half of the case does not contain any electronics, even the battery connector is mounted onto the PCB and sticks through the back case.





With the back cover removed, the first PCB is held in place with four machine screws. A ribbon cable from the display unit also needs to be unplugged. The board is then connected to a number of header connectors in various places.



A small section of board with what looks like an isolation slot around it houses an ATMEGA64L-8AU 8 bit microcontroller and a TransDimension UHC124B USB controller.

[threephase]

Flipping this board over reveals a lot more. I did not remove the shield as it was soldered in place.



The DMM input jacks are connected right onto this board, it may be viewed as a weak point, but I have not had any issues with them over the last years, although its use as a DMM will be quite light.



There are some selection relays plus a couple of PTCs next to the DMM input, the DSO has a 300V CAT III rating on the input DMM. I also noticed a little coin cell just above them, presumably for time clock backup?



The Samsung chip just by the coin cell I believe to be a 64MB SDRAM, just out of focus above that is an M29DW323DB Flash Memory

Opposite side of the input jacks there are a couple of BTC BM6 Chips that I haven't been able to identify yet.

[threephase]

There is a second board underneath the first. This is held in place by four self tapping screws into the front half of the case. This board houses the oscilloscope input channels



Flipping this board over and you find the main processor with a label conveniently placed over it identifying the revision.



There looks to be some more RAM on this board in the form of a IC16LV12816 along with an AT89C51 8 bit microcontroller from Microchip.

[threephase]

Removing this second board leaves just the PCB for the Keypad and the display in place. I decided not to go any further any remove any of these.





I'll just show a picture of the battery pack and the power supply jack that is slightly elongated. At 8 years old, it looks like the pack finally needs to be replaced as it only powers the instrument for a couple of minutes now.



edited to show missing picture

Thanks for reading

[colorado.rob]

I always appreciate a good teardown.  Thank you!

But for those of us who know nothing about this product, a few pictures of the assembled device and a brief summary describing what it is would be helpful.  All I know is that it is a DSO, the name "Agilent" suggests its a decade old, and the pictures indicate it may be portable.

[maginnovision]

https://www.eevblog.com/forum/testgear/please-share-your-opinions-and-reviews-on-agilent-u1602b!/

He was the lucky forum member who owned what ANOTHER member was looking for. at the end of that thread he also did us the favor of making a video.

Fixed the link, when adding the extra info it reformatted.

[threephase]

Sorry, as maginnovision as said, it was done to help another forum member, so I didn't think about an overview. I decided to put the teardown in a separate blog, so if someone was looking for a teardown specifically it could be found more easily.

It is a handheld, 2 channel, 20MHz DSO with a built in multimeter. Originally from Agilent and then carried on by Keysight. I believe it is officially obsolete, but there are some suppliers still selling off old stock so can be purchased new.

A couple of pictures of it next to a Keysight U1282A for an idea of its size plus the basic specifications.

Kind regards.

[rvalente]

Hello,

does anyone knows if its possible to hack the U1602B to U1604B? I'd say they could be the same unit... And the U1604B has FFT (probably a poor one but, better than nothing)

Greetings

[threephase]

Well the firmware upgrade is available from Keysight

https://www.keysight.com/gb/en/lib/software-detail/instrument-firmware-software/u1604b-firmware-update-revision-115-1911178.html

Sounds like the upgrade process is automated to recognise the meter, so would probably not work directly on a U1602B. Guess it also depends on the actual hardware on the scope inputs as well.

[rvalente]

I just upgraded the U1602B with the U1604B firmware, shows a U1604B screen, horizontal goes to 5ns and FFT is available, also, pass self-test..

Everything seems to be working properly... To easy to believe.

[threephase]

Very interesting, I might have to give that a go myself.

Thanks for letting us know.

[rvalente]

Very interesting, I might have to give that a go myself.

Thanks for letting us know.

hum, we may try a little further... I tested with my 8656A today...

The FFT is enabled
The vertical 25ns and 10ns makes no difference
Can't see signals beyond 30MHz

So, its a half a hack, enables a near to useless FFT mode.

I believe the FPGA must be updated or maybe a resistor config in board.

One thing I've noticed at version 1.1.5 in both 1602B and 1604B, the measurement menus does not works properly after update. You cant select measurements, the scope works fine but the values wont "select", there is a workaround tough, to do a power cycle.

I'll flash the 1602B firmware back and open a ticket with Keysight, that's a serious bug

[rvalente]

-3db point on mine is 25.3MHz.

[threephase]

That doesn't sound too good. At least you have the old firmware to go back to. I wonder how much support Keysight will provide for this, the last firmware update was 2012, which is quite some time ago.

It is quite likely that there are hardware differences between the two to give the higher bandwidth. As far as I know, there was never an upgrade option available from Keysight to take the U1602B to the U1604B, which there usually is if it is just a firmware license.

[satanistik]

Its someone have NAND dump for 1602 or 1604 scope? I have problem after unsuccessful firmware update. 

[satanistik]

Nobody  can read out this nand? It's better to do this before fault, because updater must communicate width scope And nand fault can brick it permanently.