Tektronix 2465B, battery impossible to remove... - Page 1
Forum section: electronics / repair

author: gtr
author_rank: Contributor
timestamp: September 06, 2025, 07:51:56 pm
content: Hello everyone.I can't get the DS1225Y-200 battery off my Tektronix 2465B. I've removed as much solder as I can with desoldering braid and a lot of flux. Now, even with the desoldering braid, no more solder is absorbed by the braid.What can I do now?Thanks!

author: edavid
author_rank: Super Contributor
timestamp: September 06, 2025, 08:06:11 pm
content: Quote from: gtr on September 06, 2025, 07:51:56 pmBorrow or buy a vacuum desoldering tool, and even then it will be a challenge. You will probably have to add solder to the pins first.If the NVRAM battery is already dead, or if you've saved the contents, it can be helpful to cut away the pins from the top side, so you can desolder and pull them out one by one. (Or it can lead to more frustration if there isn't enough pin left to get a grip.)

author: gtr
author_rank: Contributor
timestamp: September 06, 2025, 08:46:01 pm
content: Quote from: edavid on September 06, 2025, 08:06:11 pmHello, and thank you for your reply.I want to desolder it to save its contents and then transfer it to a new DS1225AD-200+ battery. I also want to solder a 28-pin socket on the front so I can easily insert and remove the new battery.I was thinking about maybe cutting the battery pins at the solder joints. It would be easier to use a desoldering pump later, as the tip is too wide to fit between the pins. However, I'm wondering if the pins will be long enough to fit into the T48 programmer I'm expecting next Tuesday. I already accidentally broke a pin at the solder joint a few moments ago.

author: gtr
author_rank: Contributor
timestamp: September 07, 2025, 12:58:12 am
content: I think the battery is glued to the PCB.

author: calibrationfixture
author_rank: Regular Contributor
timestamp: September 07, 2025, 05:27:36 am
content: Hi gtr,Gluing a Dallas to the board isn't standard practice. Sometimes the chips are stuck, even with a Vacuum Desolder Station. It is important that all pins are free (can be moved) in the center of the holes. With repositioning them you can feel them break a tiny solder bond. With 28 of these small bonds it feels like a glued chip. And you can rotate the Dallas Chip in the same plane as the board with some subtle force. It will come loose. Done this with dozens of these chips.Success,Calibrationfixture

author: IanJ
author_rank: Unknown
timestamp: September 07, 2025, 06:02:28 am
content: You risk pulling out the through hole plating so be careful and force nothing. If you pull out the through hole plating you’ll be in a world of trouble if you are not experienced.Use of a vacuum desoldering tool is a must, and a good technique is to rotate the tool on the pin to help remove solder around all sides of the pin.For stubborn pins, re-solder the pin and try again.If you can’t get a vacuum tool then use a manual desoldering tool but make sure it’s in tip top shape first. You will probably come across more stubborn pins this method, a good technique is before you start is to use your soldering iron and make sure the pins are dead vertical in their holes, I.e. not leaning onto the side of the hole as that’s where they can stick.Let us know how you get on……and remember, don’t force anything!Ian

author: MarkL
author_rank: Unknown
timestamp: September 07, 2025, 02:56:27 pm
content: Quote from: gtr on September 06, 2025, 08:46:01 pmIt sounds like it's too late for this, but you can make a backup copy of the cal data (and restore it) using more passive methods, described here:https://www.eevblog.com/forum/repair/tek-2465b-serial-number-b0506**-dallas-nvram/msg6018707/#msg6018707

author: gtr
author_rank: Contributor
timestamp: September 07, 2025, 03:48:53 pm
content: Thank you all for your valuable information. I'll look into it. For now, I was thinking of reapplying flux and solder and using a heat gun, moving it back and forth across one row of 14 pins, then the other row.When I said saving the battery's contents, I meant calibrating it.

author: edavid
author_rank: Super Contributor
timestamp: September 07, 2025, 03:53:00 pm
content: Quote from: gtr on September 07, 2025, 03:48:53 pmYou will damage the board before you get it out that way.QuoteIf you are planning to recalibrate the scope, why are you worrying about reading out the NVRAM's contents?P.S. It's confusing that you call it a "battery".

author: IanJ
author_rank: Unknown
timestamp: September 07, 2025, 03:56:13 pm
content: Quote from: gtr on September 07, 2025, 03:48:53 pmNo, you'll burn up the pcb too much. You have to use a desoldering tool, either manual or vacuum.Ian.

author: Kean
author_rank: Unknown
timestamp: September 07, 2025, 03:59:48 pm
content: Quote from: gtr on September 07, 2025, 03:48:53 pmA better technique if you are having so much trouble is to get some low melting point alloy, which will stay molten for longer allowing easier extraction.I use the Chip Quik removal alloy - available from Digikey and others.e.g.https://www.digikey.com/short/4jt98zj4(leaded solder) orhttps://www.digikey.com/short/54cfp2f2(lead free)Make sure after removal to clean up all of the remaining solder before soldering the new part/socket with your normal solder.

author: David Hess
author_rank: Super Contributor
timestamp: September 07, 2025, 06:43:37 pm
content: I waited until I had a vacuum desoldering tool before removing the Dallas parts from my 2440, and they just dropped off.If I had tried to do it without a vacuum desoldering tool, I would have soldered a length of thick wire along all of the pins, and "walked" the large DIP IC out, then removed the solder from each hole, but I do not recommend doing this because of the risk of damage.

author: gtr
author_rank: Contributor
timestamp: September 10, 2025, 12:10:47 am
content: Quote from: edavid on September 07, 2025, 03:53:00 pmThis is the calibration I wanted to talk about and that I want to save.

author: gtr
author_rank: Contributor
timestamp: September 10, 2025, 12:11:59 am
content: Quote from: IanJ on September 07, 2025, 03:56:13 pmI'm actually going to get a vacuum desoldering gun.

author: gtr
author_rank: Contributor
timestamp: September 10, 2025, 12:14:30 am
content: Quote from: Kean on September 07, 2025, 03:59:48 pmThanks for the links, it's good to know but I'm going to opt for a vacuum desoldering gun.

author: gtr
author_rank: Contributor
timestamp: September 10, 2025, 12:16:06 am
content: Quote from: David Hess on September 07, 2025, 06:43:37 pmThat's what I'm going to recommend. I'm going to buy a vacuum desoldering gun.

author: gtr
author_rank: Contributor
timestamp: September 10, 2025, 12:21:44 am
content: Thanks again for your advice.I'm going to put all this on hold and wait until the end of November to check Amazon for discounts on a vacuum desoldering gun because so far I've spent over $300 Canadian on a programmer, DS1225AD-200+, solder, flux, and two 28-pin sockets (in case of problems). I also bought two Tektronix oscilloscopes in two weeks, a 2230 and a 2465B, not including capacitors, etc.I'm sharing this PDF that was sent to me on another group, which is very interesting.https://worldphaco.com/uploads/TEKTRONIX_2465b_OSCILLOSCOPE_CALIBRATION___REPOWERING_THE_DS1225.pdfThanks everyone, and I'll come back when I get my vacuum desoldering gun! :-)

author: David Hess
author_rank: Super Contributor
timestamp: September 10, 2025, 12:32:37 am
content: Quote from: gtr on September 10, 2025, 12:10:47 amWhen I did my 2440, I was unable to recover the data from the Dallas parts, despite the calibration data still being good immediately before I removed them. I never figured out why.The 2440 series however is much easier to calibrate than the 2465 series, so I managed to do it myself which was always my plan if I did not recover the calibration data.

author: gtr
author_rank: Contributor
timestamp: September 14, 2025, 03:04:32 pm
content: Quote from: David Hess on September 10, 2025, 12:32:37 amIndeed, it seems that it's difficult to calibrate the 2465B. But even if you buy the devices specified in the manual on eBay, for example, they're already several years old and also need to be calibrated.I also have a 2230 that doesn't have SVRAM or a battery, and I'll have to calibrate that as well, but it will probably be easier.