HP5316a HP-IB ribbon cable - Page 1
Forum section: electronics / repair

author: staze
author_rank: Frequent Contributor
timestamp: October 17, 2014, 01:15:14 am
content: All,Just purchased an HP5316a off eBay, and it powers up into an E2 state (meaning something is wrong with the HPIB). Opening the device up, I notice that the cable joining the main board to the HPIB board, is missing. It's two dip sockets with a cable between them, but I'm unsure of the pinout (I plan to just make a cable). Anyone have one of these units that wants to post a good picture of the cable, and maybe even tone out the basic pin mapping (basically, is it just straight through pin 1 to pin 1, or does something cross over)?If taking a picture, could you also take a picture of the area around the main IC. There's a small 14 or 16 pin socket in the area that's empty on mine, and appears to be that way in the documentation as well.Thanks!

author: amc184
author_rank: Regular Contributor
timestamp: October 17, 2014, 08:09:25 am
content: I just took some photos of my HP 5316A. I didn't get a very good shot of that cable, but hopefully this helps.I also had a look at the service manual, and it's just a straight through connection.

author: staze
author_rank: Frequent Contributor
timestamp: October 17, 2014, 06:08:28 pm
content: awesome, thanks. Can you confirm that small socket next to the main CPU is empty?Thanks!

author: staze
author_rank: Frequent Contributor
timestamp: October 17, 2014, 06:16:27 pm
content: other question is, what the heck do they call these DIP cables? Am curious what one would cost, but Google-fu is failing...

author: SeanB
author_rank: Super Contributor
timestamp: October 17, 2014, 06:23:28 pm
content: Ribbon cable and IDC interconnect socket.

author: KJDS
author_rank: Super Contributor
timestamp: October 17, 2014, 06:24:18 pm
content: Quote from: staze on October 17, 2014, 06:16:27 pmputidc connector ribbon cableand you'll be spoilt for choice

author: staze
author_rank: Frequent Contributor
timestamp: October 17, 2014, 06:24:36 pm
content: nice, thanks!http://www.jameco.com/1/1/25575-8200-28-connector-idc-dip-plug-28pin-1a-use-37840.htmllooks right on

author: amc184
author_rank: Regular Contributor
timestamp: October 17, 2014, 09:40:39 pm
content: That part looks like it'll do the trick. The small socket should be empty, I think it's a test connector.

author: staze
author_rank: Frequent Contributor
timestamp: October 18, 2014, 04:05:15 am
content: amc184:Noticed yours has been recapped. I am not seeing markings on the stock caps, and the copy of the service manual I have doesn't seem to show their full values. I'm guessing c37 is a 15V 7500uF, and c38 and c39 are both 10v 3900uF. What is installed in yours?And yeah, those values seem crazy high for something like this. Maybe because caps back then had sucky ripple tolerances?On second look, I see they're all 20V, with the capacitance listed. Still seem huge for something like this.The ones I see in your picture, amc184, look MUCH smaller. Any info would be great.Thanks!

author: amc184
author_rank: Regular Contributor
timestamp: October 19, 2014, 01:49:58 am
content: I used 8200uF 25V for C37 (originally 7500uF 20V) and 4700uF 25V for C89 and C39 (originally 3900uF 20V). I tend to stick fairly close to what was originally fitted, I don't take the effort to check the original designer's choice unless I really think I need to. They're so much smaller thanks to the leaps and bounds made in miniaturizing electrolytic capacitors.Mine didn't work properly before I replaced them. I also replaced the tantalums, I'm sure they worked properly, but I see them as a safety hazard.

author: staze
author_rank: Frequent Contributor
timestamp: October 19, 2014, 02:13:22 am
content: Yes, mine isn't working right either. Still throwing errors about hpib. The 5v rail is fine, but the 3.0 and -5.2v are way off, and scope shows them oscillating (bad filter caps).Damn on the 8200. Those are harder to come by. :/ thanks!

author: amc184
author_rank: Regular Contributor
timestamp: October 19, 2014, 07:48:54 pm
content: What supplier are you using? The exact one I used was a Nippon Chemicon EKMH250VSN822MP35S. The main reason is because I had a bunch just lying around, but they were nicely suited. They're snap in type, which fits the screw terminal pattern on the PCB nicely.

author: staze
author_rank: Frequent Contributor
timestamp: October 20, 2014, 08:52:23 pm
content: Quote from: amc184 on October 19, 2014, 07:48:54 pmYeah, I think I found them on Digikey. Only issue is they don't have the IDC connector... they have 40 pin ones... think I could just cut off the un-needed 12 pins (I don't see why not, other than the structural changes)?

author: amc184
author_rank: Regular Contributor
timestamp: October 20, 2014, 10:42:49 pm
content: I don't think that's a great idea. The top and bottom part of these connectors clip together at each end, if you cut one end off it's going to come apart.These connectors are going to be hard to find, as they're fairly obsolete. I found a listing for one at Digikey (http://www.digikey.com/product-detail/en/09170289622/09170289622-ND/4335498), but it's not stocked. You're going to have to go further afield for these. Here's a few possibilities:-http://www.king-cart.com/phoenixent/product=MALE-IDC+CABLE+MOUNT+.1SP+IDC+HEADERS+%2526+DIP+IDC+PLUGS/exact_match=exact(part number HWS15893)-http://www.jdr.com/product_p/idp28.htm-http://www.cablesandconnectors.com/09800-09.HTM(catalogue number 09822)

author: staze
author_rank: Frequent Contributor
timestamp: October 20, 2014, 10:52:05 pm
content: Yeah, shipping is just murder on stuff like this. Ah well...okay, so I guess two orders... one from digikey on caps, one from cables and connectors for the cable ends... Thanks!What was your unit doing prior to replacing the caps?

author: amc184
author_rank: Regular Contributor
timestamp: October 21, 2014, 08:01:18 pm
content: It was working, but flaky. Sometimes it would show an E3 error, and it wouldn't trigger over all of the frequency range it should have (especially at the low end). I think the E3 error may have actually been down to a dirty internal / external clock source selection switch, which I also replaced.That's it really, the standard stuff I do when I buy an old instrument; clean the controls and replace the electrolytic capacitors.

author: staze
author_rank: Frequent Contributor
timestamp: October 31, 2014, 02:13:00 am
content: amc184,One last question, hopefully. The channel B BNC jack is mangled on this guy. It's labeled as J2 in the documentation, but I'm not sure what to replace with. Do you have any clue what to use? Looks like it's probably just a surface mount one...

author: staze
author_rank: Frequent Contributor
timestamp: October 31, 2014, 02:45:25 am
content: The jack itself has written on it 24931 28JR175-4, which would seem to be a well obsolete Souriau part... there must be something that'd work though. =/Thanks!

author: staze
author_rank: Frequent Contributor
timestamp: November 06, 2014, 08:28:03 pm
content: Recapping the unit, and using some jumper wires between the gpib and main board got the unit working. =) The two 3700uF caps were completely gone (15pF capacitance), but the larger 4200uF screw terminal one appears to be fine (I replaced it anyway). Waiting on an order for the DIP IDC connectors, and ribbon cable. Also thinking about replacing the main timesource with an OCXO, but I'm curious how much current the +5V rail can supply. Given the size of the filter caps, I would guess quite a bit, but do you have any thoughts? Looks like the optional OCXO for this unit uses the +7.5V rail for it's heater.