Help Locating Part for HP 5316B Universal Counter - Page 1
Forum section: electronics / repair

author: smgvbest
author_rank: Unknown
timestamp: July 11, 2015, 08:11:06 pm
content: HelloI've been repairing a HP 5316B Universal Counter and have everything working well except the gate time.Come to find out when I took it back apart and removed it completely from the case the Gate Pot was sheared off the PCB.The Part is A1R31, 2100-3905 500K 300deg, Pot with SwitchYou can see in the pictures below the part itself and how it sheared offI've looked on the web for this part (long shot I know)So I have a few questions1. i see it's riveted together. can I remove the rivets and try to repair the lugs so it can be resoldered?without a rivet gun that small can i use small screws to put it back together?2. is it worth contacting the HP (just using the original name) to see if they may have any of them?3. anyone know where I might obtain one? I tried ebay and no luck and found one compant on the web but they are not replying4. anyone have one they'd be willing to sell?Here's the pics showing part number and the sheared off pcb pins

author: kolbep
author_rank: Frequent Contributor
timestamp: July 11, 2015, 08:17:40 pm
content: Looks like there is enough of the pins exposed to be able to solder small jumper wires (leads trimmed off resistors work nicely). Then you can solder those leads to the board, and, once tested, epoxy the pot in place to relieve stress.If there is not enough exposed pins, grind the body down a bit at the pins, using a Dremel , or even scrape it away with a craft knife, until you have enough exposed of the pin to solder onto

author: smgvbest
author_rank: Unknown
timestamp: July 11, 2015, 08:22:28 pm
content: kolbep, I did think of that but was concerned when I solder it to the board they may come loose but could try it. it can't hurt

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 11, 2015, 09:20:37 pm
content: Hard to see how it is mounted but if you can rotate it 900or 1800you can use wires to reconnect it and then protect it with some hot glue/epoxy/silicon. That way you don't have to worry they come loose.

author: smgvbest
author_rank: Unknown
timestamp: July 11, 2015, 11:18:51 pm
content: It's PCB MountedHere's the PCB itselfThought I had rotated the picture but you can see where it was mounted on the PCB at the bottom

author: TheSteve
author_rank: Unknown
timestamp: July 11, 2015, 11:33:18 pm
content: Soldering leads on the pot looks to be quite reasonable to do. The bigger challenge is holding it securely in place afterwards. How busy is the bottom of the PCB - any chance of drilling a hole on either side of the pot to use a clamping system to help hold it in place? You could epoxy it in place and then also use a zip tie over the top.

author: amyk
author_rank: Super Contributor
timestamp: July 12, 2015, 02:40:49 am
content: You clearly have the SMD version of the pot now.It can probably be reflowed back onto the board, just add some solder balls to the contacts. If you want to mount it more securely, then a metal strap over the top soldered into some holes on the board should work.

author: Vgkid
author_rank: Super Contributor
timestamp: July 12, 2015, 05:10:55 am
content: Take some size measurements, as one of these might work(Bourns are blue).http://bourns.com/ProductLine.aspx?name=industrial_panel_controls

author: smgvbest
author_rank: Unknown
timestamp: July 17, 2015, 10:18:05 pm
content: I had to deal with a basement flood and a kitchen flood in the same week so sorry I've not gotten back to this until now.Vgkid, I'll take a closer look, so far I found one that's pretty close, the pin spacing the same but there are other dimension to checkIf not I can try the SMD approach (I like that one) or routing wires.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: July 18, 2015, 01:56:44 pm
content: There are some good suggestions already given.I had a control that was a channel selector that this happened to a while back. The control was similar to yours but was 5k.I drilled out the rivets and took the switch apart. I then was able to solder leads to the pads. With a small rotary bit I cut slots in the case for the new leads. Put it all back together using long screws and nuts.Worked like a charm. But it is delicate work.

author: dadler
author_rank: Unknown
timestamp: July 18, 2015, 10:55:33 pm
content: If it were me, I'd go with your original plan and drill the rivets out. Then cut some leads off a donor part (I'm picturing a TO-220 something-or-other), solder them internally, and reassemble with small screws. Can't be sure of the inner workings until you open it up.At least this way, you don't create the secondary problem of having no mounting mechanism.

author: smgvbest
author_rank: Unknown
timestamp: July 19, 2015, 04:15:05 pm
content: Thank you all for the advise on thisI had a basement flood and kitchen flood happen so have been dealing with the clean up from that. fortunately neither was major but cleaning up and drying things out is a pain. Did not want anything to think I had abandoned my posting.Knowing that others have opened up similar devices helps.Eye's aren't what the used to be but do have an inspection microscope (off ebay) so I can see what I am doing.I just ran across some really old stuff while cleaning on found some 7805's I could use as donner parts.I'll try to post some surgery photo's for those interested