Got a used HP 1661C logic analyzer, Have questions about it - Page 1
Forum section: electronics / testgear

author: poot36
author_rank: Frequent Contributor
timestamp: July 15, 2015, 03:34:50 am
content: I am going to get a HP 1661C logic analyzer that is shown working in the auction but I want to know if there are any traps for new users? I will hopefully receive it in the upcoming week and am trying to prepare myself for when it comes. I have read the general operations manual as well as the limited service manual. I am wondering if there is anyway to back up the floppy disks that come with it as well as the hard drive (and maybe the eprom and flash rom chips as well). I think I am going to have fun connecting 30+ wires to my broken super nintendo (SNES) but other then that I think it is pretty straight forward to operate? I assume that I would want to run it in state mode not timing for this application?

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: July 15, 2015, 12:38:34 pm
content: I have a 1670 and love it, its fantastic bit of kit.make sure you get the pods with grabbers, if you dont have them, they will cost another 100 odd dollars. I have a little video I made to show someone using it (just ignore me where I try and stuff a hex number into a binary spot lol!)if you have an active CLK type pin, you can run state mode, if you dont have a CLK type pin you can tie into, you need to run in timing mode.

author: PaulAm
author_rank: Frequent Contributor
timestamp: July 15, 2015, 01:17:54 pm
content: The major thing to worry about on that series is the power supply going poof. I got one in that worked for a couple of hours before the power supply died. The power supplies were made under contract to HP so there's no official schematic available, although there's a reverse engineered one floating around. Capacitors are the usual suspects though.I ended up buying another LA since that was cheaper than buying just a power supply and I didn't have time to trouble shoot the dead one.

author: poot36
author_rank: Frequent Contributor
timestamp: July 15, 2015, 01:23:04 pm
content: That's great to know. It does come with 3 pods so I think I will have 48 total connections that I could make. The SNES does have a clock pin so as long as it is working properly I can run the analyzer in state mode.

author: free_electron
author_rank: Super Contributor
timestamp: July 15, 2015, 03:39:06 pm
content: Yeah the power supply. they call em skunks. as they stink really bad when they go.There is no need to backup. The firmware can be downloaded from hp website. the machine can image a blank harddisk all by itself. Simply pop in the floppies and it installs.the flash rom is a tssop package. pretty hard to desolder and dump.but like i said : no need to.

author: Shock
author_rank: Super Contributor
timestamp: July 15, 2015, 07:15:25 pm
content: A power supply failing (without taking out anything else that is) is almost a blessing in disguise if you ask me.

author: poot36
author_rank: Frequent Contributor
timestamp: July 16, 2015, 01:48:01 am
content: Ok so I have to worry about the power supply. The unit came with more floppy's then just the boot disk. How would I go about backing those up? When I get it should I power it on or should I take it apart and replace the filter caps in the power supply? The unit came from eBay so if it is defective I should be able to get my money back.

author: poot36
author_rank: Frequent Contributor
timestamp: July 25, 2015, 03:49:30 am
content: Ok, I now have the logic analyzer in my hands and WOW it has lots of features! It has everything except for the LAN interface and if I am reading the hard drive correctly it was last used in 2002. It boots fine and displays no errors and has no screen burn in. The cables were a little messy but I have fixed that now. I did notice that this thing has a real time clock in it and am wondering if I should replace or add on a new battery (I think it has one of those Dalles RTC chips that you can remove the plastic to get to the battery contacts). The time was out by a day or so. How do I back up the hard drive in the unit? Also should I upgrade the os to the latest version or not? Also is it a good idea to plug the ends of the pod cables directly into a 0.1 inch standard header or should I try to get all of the required mini grabbers?

author: georgd
author_rank: Regular Contributor
timestamp: July 25, 2015, 02:28:10 pm
content: Quote from: poot36 on July 25, 2015, 03:49:30 amIt's a bad idea to connect LA inputs directly to DUT. Inside probe ledads has passive divider maching network.Read before brochure from Keysight:Probing Solutions for Logic Analyzers (http://cp.literature.agilent.com/litweb/pdf/5968-4632E.pdf).Georg

author: poot36
author_rank: Frequent Contributor
timestamp: July 25, 2015, 03:21:31 pm
content: Ok, I won't do that. I have attached a picture of the pod probe ends to better show what I am trying to plug a square pin into.

author: nctnico
author_rank: Super Contributor
timestamp: July 25, 2015, 07:03:57 pm
content: You can put these header connectors on pin headers. They do need some care and wiggling but they will also accept thinner wires.

author: poot36
author_rank: Frequent Contributor
timestamp: July 25, 2015, 07:33:45 pm
content: Ok, I was just concerned that the connectors were only for the smaller circular pins that are on the mini grabbers and that I would damage them by trying to place them on a bigger square pin.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 25, 2015, 08:18:50 pm
content: You should be able to backup the drive with any of the many image tools assuming you still have an old PC. There are image tools for the floppy as well. I use DriveImage and raw write.

author: poot36
author_rank: Frequent Contributor
timestamp: July 25, 2015, 08:34:16 pm
content: Thanks for the tip. I do have an old pc with a ide interface on it. Is there anyway to back it up with out taking apart the logic analyzer? It still has its HP cal sticker and a nist cal sticker that expired in 2000. The last date on the files on the hard drive are from 2002.

author: poot36
author_rank: Frequent Contributor
timestamp: July 29, 2015, 02:05:49 am
content: I have figured out that this unit does not need the hard drive to boot so I have just used the built in copy utility to transfer all of the data on the hard drive to a floppy and copyed that to my computer. I do have a question though where is the calibration data stored on these? Is it in the flash rom chip or on the memory of the rtc chip? Also when I am running in state mode why can't I view the output of the clock line? It is selectable in the menu and only shows a constant low level (0) on the waveform display. Would updating the firmware to 2.02 from 1.06 (i think) fix it? Or is this not possible in state mode?