Hameg HM1004-3  Trouble and Newer version service manual ? - Page 1
Forum section: electronics / repair

author: Ovi4
author_rank: Contributor
timestamp: June 02, 2020, 09:57:12 pm
content: Hi all, I wonder if anyone here could possibly help with the following issue please:Hameg HM1004-3 (100MHz analog) scope that I recently acquired with the following symptoms as described by the previous owner,, Last time it worked ok and switched it off but didn't need to use again for about 3 months and now when try to power up the unit some lights quickly flicker and disappear,then it beeps a few times and that's about it. No controls are active and nothing shows on the screen".Well, I've observed a short flash on the screen when switching the power button OFF. Now, to me, that is a,,real hint,, that the HV voltage multiplier needed forthe CRT still works and that there is HV present at the CRT).One other problem I've spotted is on the Readout Board two 6.8 ohms SMD resistors had strong burn marks around them and they seem to descend from the+12V line fed viaa ribbon cable and had them tested but they measure just fine and still within the specified value. Also, there is a dual op-amp (TL082C) that is kind of hot to the touch but replacing it with a brand new onedid not change anything and it is still as hot as the old one was.Regarding the PSU I know that it has to provide +5V, +12V -6V, +65V, and +115V voltages probing I found the following values:+5V=5.38V, +12V=12.28V, -6V=6.12V, +65V=66.6V, +115V=118V All measurements have been performed with a brand new FLUKE 289 Meter.Looking at the CRT's filament, I can clearly see that it is lit.Upon closer visual inspection, two SMD resistors On the PSU board also seem a little black and no markings on them but testing they measure 283 ohms and 4 ohms respectively. I have no idea if they are still within the specs or not without having a proper schematic diagram at my disposal.So the main problem I'm facing is getting the right kind of service manual. I already found a service manual (online) as per the model number of my scope but to my surprise,it is totally different than my scope. Every board I've looked at so far has fairly substantial differences in layout and even slightly different connectors.Looking at the manual it says designed in 1996 and it shows a PSU diagram that is version 1 but my scope was made in 2002 and has a sticker on the PSU that says PS1004 Ver. 2A and is dramatically different than what Version 1 in the manual shows. And since none of the boards have any silkscreen on them, I simply cannot identify the component numbers to try to find their real value in the schematic diagrams or the provided component tables.I wrote to Rodhe and Swartz (UK) kindly asking for the service manual 2 months ago but I got no reply. I wrote to them again 3 weeks ago but still nothing.And yes I've got the right email address. It has been confirmed.I've attached a few photos showing the PSU diagram from the manual and the real-life one from my scope.Now, going back to the readout board it has a really strange flat (ribbon) cable that doesn't seem to belong there, and at 1 end one could easily connect it wrongly to the other board and damage the readout board that way. So, the question is: is this cable like this from the factory? I really don't know at this point. Pictures attached.I don't know if it has been plugged in the correct way since I don't have any similar pictures in the service manual to compare it with. There are lots of pictures shown in the manual but for the 1996 model only. I really don't know at this point what to do anymore without the right manual.So if anyone could share a proper (newer) service manual or some other form of help perhaps some pictures with the readout board and the ribbon cable would be kindly appreciated. Tnx.PS. I do not have access to any other Hameg scopes with identical specs for comparison so, that is out of the question.

author: AwaisN
author_rank: Newbie
timestamp: July 05, 2020, 06:04:37 pm
content: Hi,Have you checked this link for the manual?https://www.scribd.com/document/381437371/Hameg-1004-1004-3-Oscilloscope-Calibration-Manual-Board-layout

author: Ovi4
author_rank: Contributor
timestamp: July 05, 2020, 10:05:36 pm
content: Hi, tnx for the link but as stated on my previous posts I already have this manual. This is the very first (year1996) manual where all boards have revision 1 marked on them but my oscilloscope was made in 2001 and all of my boards differ vastly from what you see in this manual, they all have revisions 2, 2A 3 and some of them even 4 and no layouts match at all. Even ribbon cables have been changed and look different. So, again, cannot use this manual at all. There is another manual apparently that is marked as edition (the year 2000) and I know that some people were lucky enough to own such an updated manual are just a matter of finding those people. Meanwhile |I've spoken with the company that took over from HAMEG and they still do service old HAMEG scopes. I've asked them nicely for the updated manual and they do have it but refused to let me have a copy of it. They said that only occasionally give out schematics and even then will never ever give out the full manual. They will strictly provide maybe a module or who. And yes they have agreed to send me the updated power supply only and refused to give out anything in relation to the readout board and basically, that is exactly what I need. They've said that I could send them my scope in Germany for a full,, in house,, repair and calibration at a cost but there is no way I'll ever do that cos the cost of the repair thru them will almost always be more than the scope itself is worth, so no....that route is out of the question.

author: AwaisN
author_rank: Newbie
timestamp: August 05, 2024, 07:16:27 am
content: Hi, it's a long time for any post in this topic. Did you manage to fix your oscilloscope? I am attaching HM1507-3 service manual.My HM1004-3 still needs to be fixed. When I try to turn on my HM1004-3, it turns on, gives beep and then turn off and this sequence goes on continuously. I think that I did mistake during connecting W1000 and some wires got short with each other.Can I test voltages on power supply outputs after completely disconnecting it from the oscilloscope even High Voltage transformer output connection which is going to CRT?Any suggestion will be highly appreciated.Thanks and regards