Hameg HM1004-3 Oscilloscope - Page 1
Forum section: electronics / repair

author: et302
author_rank: Newbie
timestamp: May 05, 2022, 06:18:55 pm
content: Have a repair question for my Hameg HM1004-3 Oscilloscope.When I cold start my scope, which can be as short as after 2-3 hours of no use, it does not power up right away - I hear a total of 10 beeps, 4 beeps followed by a short pause, and then 6 additional beeps.After 3 or 5 more restarts, it comes up normally - 2 beeps.I'm surmising that this is related to the scope's Power Supply. I'm posting this to see if anyone has had this happen to their instrument and what steps were taken to resolve it. Very likely, this will need me to open up the scope, but before I go through that, any wisdom/insight that someone reading this can share would be greatly appreciated.My scope in running software FC 3.30 R01.82, and when it does start, all bootup checks that it goes through are successful.

author: m k
author_rank: Super Contributor
timestamp: May 18, 2022, 03:07:59 pm
content: The power supply seems to have all kinds of stuff, from one version of schematics, including line present indicator opto.https://www.eevblog.com/forum/repair/hameg-hm1004-3-newer-version-service-manual-and-help/Can you check how all supply voltages are when it is not starting?It seems to have some life since it can beep.

author: et302
author_rank: Newbie
timestamp: June 21, 2022, 05:20:43 pm
content: Does anyone have a Service Manual for a newer Hameg 1004-3. The downloadable version of the Service Manual, 4S-1004-00E0 - 1st Nov. 1996 is for an older revision of the scope (PCBs are different than those shown in the manual). The power supply outputs are quite different in the revision that I have. I've reached out to Rohde Schwarz, but got a very curt - "...we don't provide Service Manuals" response.To rule out if it was related to a connection, I've cleaned out the scope, all the PCBs, and contact cleaned all the flat cable connections, but have the same behavior. Cold start, it never powers up - I hear 10 beeps, 4 fast beeps followed by a short pause, and then 6 fast beeps and it remains off. After a number of more restarts, it comes up normally (no errors in the keyboard check, rom check, etc.) with 2 beeps.

author: shakalnokturn
author_rank: Super Contributor
timestamp: June 21, 2022, 10:40:28 pm
content: Is there a backup battery anywhere? (For last state and/or timekeeping).If there is, I'd start by checking how low that goes when un-powered.

author: TaylorD93
author_rank: Regular Contributor
timestamp: June 22, 2022, 11:51:25 am
content: I have a 2001 built 1004-3Unfortunately I have had no luck finding any schematics.I have contacted Rohde & Schwarz UK who told me the schematics do not exist.I have contacted others including ex HAMEG staff and ive been told that even Michael at Sky messtechnik cannot distribute the schematics because of a Non Disclosure agreement.Mine has a PSU issue as well as a fault in the acquisition circuitry but without the schematics I've deemed the scope is pretty much scrap.

author: shakalnokturn
author_rank: Super Contributor
timestamp: June 23, 2022, 12:25:51 am
content: You could post detailed photos here with a better description of problems, that may get you further than looking for unreleased schematics.