Lecroy DDA-5005 Control Pad Repair - Page 1
Forum section: electronics / testgear

author: ReedTriesToRepair
author_rank: Contributor
timestamp: January 19, 2023, 11:47:41 pm
content: I'm attempting a repair of an oldie-but-goodie Lecroy DDA-5005. It has an issue with the panel controls: the scope does not receive any inputs from any buttons or potentiometers, and none of the lights light up. The scope works great with the keyboard and mouse, but it is missing the good old manual scope controls and I would like to get those working again.This problem preexists me, and I bought two of these scopes at once. On one of them, the screen doesn't power on (a project for another day), but I have tried swapping out the control pad, no dice. Ignoring the one-in-a-million chance both control pads are shot, there has to be something else going on here. Further, since the pots aren't responding, it has to be another problem because the pots stick through the control button pad into the frame.Has anyone seen this problem before? Looking for any advice before I peel one layer deeper into the onion.

author: ReedTriesToRepair
author_rank: Contributor
timestamp: January 21, 2023, 01:21:54 am
content: Update: After tearing down about half of the computer side of the scope, I swapped out the circuit board behind the control pad and now it works! I wasn't expecting the solution to be that easy. It seems like the front of this scope has seen some physical trauma and some of the knobs were pushed in, which may have contributed to the issue. Also when I pulled the board out it was super dusty (>1 inch long dust balls, see pictures), which also may have contributed.When I was inside the scope I saw some expanding caps on the mobo which have dented their casing. Looking like they could blow any day. I suppose I should replace those. As they say, work begets work.Also today I got my other scope of the same model to power on the screen and go into BIOS, but I think the HDD is fried because it doesn't boot up. I will make a copy of my other scope's HDD and throw it in to see if it works. Then I will either need to see if I can source a new control pad circuit board or repair the old one, but I will cross that bridge when I come to it... progress...

author: hpw
author_rank: Frequent Contributor
timestamp: January 21, 2023, 03:31:00 pm
content: Nice that you find out the dust issues, so you where fasterDo you run on W2K? Always best to clone using an SSD 120G (max)Hp

author: ReedTriesToRepair
author_rank: Contributor
timestamp: January 21, 2023, 04:13:18 pm
content: Quote from: hpw on January 21, 2023, 03:31:00 pmYep, W2k was what came on the PC and I hadn't considered an upgrade. How can I find out what versions of Windows the software is compatible with? I would love to get it as high as XP if possible.I was going to put another HDD in there, but make a backup copy of it in case of failure. 120gb IDE/PATA SSDs seem oddly expensive on eBay.

author: DaJMasta
author_rank: Super Contributor
timestamp: January 21, 2023, 07:09:42 pm
content: Just cloning the drive over to an IDE SSD would make for a substantial performance increase, you can install standard XP on these machines (but installation of XStream needs a second driver pack in addition to itself and the motherboard drivers), but I'm not sure you'll see any real performance or feature difference - I don't know if it's worth reinstalling everything.

author: hpw
author_rank: Frequent Contributor
timestamp: January 21, 2023, 07:46:23 pm
content: Quote from: ReedTriesToRepair on January 21, 2023, 04:13:18 pm1. the mobo has 2 SATA connections... use them and keep your PATA HD as separated as it gets.2. as you already have a CD-R drive, boot from them and connect the SATA SSD to one of the free SATA ports3. I used to clone using RDriveImage7 as supporting W2K & XP, than clone once more to 2. SATA SSD to play as upgrade to XP4. there are many talks about here on eevblog.. just search even the 5005the SATA SSD important MAXIMAL 120G as I used Kingston's as cheap on local store, otherwise a nightmareJust fiddle out your current XStream version... upgrade to V8 is the last possible (usual V6 to V8), but for downloading ask on LeCroy support by email.Booting will be using SSD any faster also 4G memory and faster CPU's...hp

author: hpw
author_rank: Frequent Contributor
timestamp: January 21, 2023, 07:55:34 pm
content: BTW:- I am still looking for a half height floppy dual USB-2 holder (3D STL) as some newer DSO's gets it already build on the front.- Are your front Bezel's any broken?

author: DaJMasta
author_rank: Super Contributor
timestamp: January 22, 2023, 03:29:40 pm
content: I haven't seen a WP7k tyoe board originally running windows 2000 with SATA ports, and while I don't know if windows 2000 can boot from an SATA drive at all, windows XP needs special drivers incorporated into the installation - slipstreaming them, if I remember right - to be able to boot from it at all. Maybe the very latest release of this line of scopes had them, but I don't think most did.I've also run into a problem with faster CPUs - yes, upgrading is a good idea, but most P4 motherboards don't support the whole line, and again a limitation with XP is that while it can take advantage of more than one core (or hyperthreading, as is more likely to be present in P4s), you must install the OS with that CPU in place and with HT enabled in BIOS - it will install different OS components for a multicore system and you'll run into front panel issues, of all things, if you swap to multicore on a single core installation.

author: ReedTriesToRepair
author_rank: Contributor
timestamp: January 22, 2023, 09:53:13 pm
content: Yes, what DaJMasta is saying is correct, I have an early model (number 139 off the assembly line!) that doesn't have any SATA ports, all IDE here. I was going to do a simple RAM upgrade as well once it's in working shape.It sounds like it's more trouble than it's worth to upgrade the OS. Both are obsolete, so there's really no benefit other than being able to play pinball natively in the OS.hpw- I like the direction you're going with replacing the front floppy drive with USB ports. That would be a very functional upgrade, let me know if you come up with an STL. If I get some time, I may be able to design one but it's not on the top of my priority list right now.And yes, as with most of these units the front bezel is in 100 broken pieces, so I'm 3D printing one I found on thingiverse which has been referenced before on the forum.I have some BMA connectors in the mail that I plan to use to make some BMA-to-BNC adapters since I don't have any BMA probes and don't feel like dropping thousands of dollars on the oem Lecroy probes. Do you have any advice for fashioning those?Thank you both for your help so far- I have some replacement parts on the way and will probably have more questions.

author: hpw
author_rank: Frequent Contributor
timestamp: January 23, 2023, 11:44:50 am
content: May read "sixtimesseven" users contribution as he did replaced the mobo with any newer. But requires any HW tweaks to get the screen & touch-panel working.The newer WM / SDA uses Intel Desktop Board D865GLC as have 2x SATA connections. Using latest BIOS. Still on EBAY available.As running 3GHz 800FSB and 4G BUT SINGLE Core on BIOS!!!As for SMA/BNC adapters, there is a SDL model may from "sixtimesseven" as 12 >> 14cm fan adapters for industrial Noctua model.1M input adapters are still high prices at Ebay... but seams no way. Any active probes as missing/lost most required connecting pin's.For cloning boot with CD-R and have the new SATA SSD connected, while the target must be always the destination HD connected to the mobo.The mentioned RDriveImage7 comes as free for trial but helps to not destroy / touch the original MASTER!!!I had some bad experiences with 3D printing & shipping from the know Asia land (see my pictures on this forum) as wrapped and broken, while the finish of the 3D printing gets sand blasted. So my next will be any more expensive as 70$US as went for black printings. So ask for pictures before shippingI have also some PATA/SSD but as SSD SATA 128G any on next PC shop.YES, waiting for a STL model as dual USB supported adapter for 1/2 sized Floppy (slim model)BTW: the time decoder is usual a first target for exchange. Alps or Bourns brands only as cheap for an xxkUS DSO brand

author: hpw
author_rank: Frequent Contributor
timestamp: January 27, 2023, 11:26:34 am
content: Quote from: ReedTriesToRepair on January 22, 2023, 09:53:13 pmI have one question, as attached picture.May you post the jumper coding on your front as WM & SDA any different... it is marked in the orange rectangle and your will be any different as may T10 or T30Hp

author: ReedTriesToRepair
author_rank: Contributor
timestamp: January 27, 2023, 08:29:12 pm
content: Mine has the T10 jumper soldered (just that one). What is the functional difference between jumps?

author: hpw
author_rank: Frequent Contributor
timestamp: January 27, 2023, 08:35:59 pm
content: Quote from: ReedTriesToRepair on January 27, 2023, 08:29:12 pmWell, IMHO all information about this jumpers' is kept hidden...It may how the "Default" button acts... knowing what model it is as T00 is as the WM and yours T10 the DDA

author: ReedTriesToRepair
author_rank: Contributor
timestamp: January 27, 2023, 08:39:40 pm
content: I see, they recycle control pad designs between models... this may be useful info for getting my other control pad working, thanks. I may have to try to buy one off of someone but this greatly widens the market pool if I can find one off of a WM or SDA scope.

author: ReedTriesToRepair
author_rank: Contributor
timestamp: February 13, 2023, 11:26:44 pm
content: I have an update, in case it's helpful to anyone that may work on these in the future.The keypad was indeed repairable, it just required all of the pots/dials to be re-seated, cleaned, and clamped down.It turned out in the end that the HDD was not the issue with the no-boot scope, it was a bios configuration issue. The CMOS battery had died so the mobo forgot the bios settings and didn't know how to boot from the IDE HDD correctly (I guess this was before the days of automatic configuration of the HDD...), but I got it working after adjusting a bunch of settings.Looks like everything works! The repair went better than I thought it would, thanks for your insights. Now to continue hunting for affordable probes...