Hameg 203-5 troubleshooting  - Page 1
Forum section: electronics / repair

author: lapoltba
author_rank: Contributor
timestamp: December 22, 2015, 03:02:28 am
content: I acquired those scope a couple years ago and found that only one channel would sweep and show a trace. I had intended to repair it then but never got around to it.I now have the time and I am digging into it. After looking for obvious catastrophic failures I plugged it in again to see if the one channel still worked. It did not.I am going to check the power supplies tomorrow night as I had an emergency network issue here and had to reconfigure my router.The German manual on hameg's site is only slightly helpful. I'll print off the diagrams for reference tomorrow, nut translating bots and pieces is painful.Symptoms:Powers on and shows two dots but will not sweep.Putting a signal in from my FN generator causes the dots appear to wiggle but still no trigger or sweep.X and y position adjust seems to work fine.

author: tautech
author_rank: Super Contributor
timestamp: December 22, 2015, 03:14:04 am
content: Manual link:http://elektrotanya.com/hameg_hm203-5_oscilloscope_sch.pdf/download.html3.3Mb

author: lapoltba
author_rank: Contributor
timestamp: December 22, 2015, 03:17:17 am
content: I have tried downloading from three different computers at work and home with three different browsers and all combinations of security settings I can think of. I cannot download anything from that site for some reason.

author: tautech
author_rank: Super Contributor
timestamp: December 22, 2015, 03:29:31 am
content: Quote from: lapoltba on December 22, 2015, 03:17:17 amFor that site you must wait for the site to assess that you are eligible for the download, it can take a little while and then click the small "Get Manual" link that appears in the text.The site only permits 2 free downloads/day.

author: lapoltba
author_rank: Contributor
timestamp: December 22, 2015, 02:33:00 pm
content: I was just able to get it while at work. I did have a username and login at one point for that website but it appears to have expired. They have no record of my email either. Anyway, I have some stuff to look at now, first being all the voltages with the exception of the high voltages since the CRT seems to be working fine.

author: oldway
author_rank: Super Contributor
timestamp: December 22, 2015, 06:22:58 pm
content: You can also download the service manual with schematics from Hameg support but only in german.http://www.hameg.com/manuals.0.html?&no_cache=1&L=0

author: lapoltba
author_rank: Contributor
timestamp: December 22, 2015, 06:28:27 pm
content: QuoteI did that already. I don't speak/read German. The manual linked above is a bit more helpful with English comments.

author: KJDS
author_rank: Super Contributor
timestamp: December 22, 2015, 06:37:30 pm
content: The first thing to try on any old analog scope is to wiggle every switch back and forth a dozen times. Then make sure that the triggering is set to line so that it will sweep regardless of input.

author: lapoltba
author_rank: Contributor
timestamp: December 23, 2015, 01:12:18 am
content: All the low voltage rails I could find looked good. I cannot get any sweep regardless of any switch settings (tried setting the trigger selection to line). I didn't print out the manual today and scrolling around the PDF is tedious. I'll print it out tomorrow on 11x17 for easier reading and dig deeper.I'm open to suggestions. When connecting to the CAL output I get two dots on the screen at approximately 0 and 1v. They do move around with the y position, but only move about 1 division at 50us time division. Hopefully that is enough info for someone to maybe point me in the right direction. I really don't know what i'm looking for at this point.

author: tautech
author_rank: Super Contributor
timestamp: December 23, 2015, 02:17:06 am
content: Screenshots/pics are always good to see but from your latest description it sounds like there is no sweep.Sign of a triangle waveform in the "Ramp Generator" on the X board is where to look first.Collector of T509 ?

author: lapoltba
author_rank: Contributor
timestamp: December 27, 2015, 03:23:04 pm
content: Thanks for the tip. Unfortunately I don't have another scope to check the signal at the moment. I may be picking up a tek 2215 today though.

author: lapoltba
author_rank: Contributor
timestamp: December 27, 2015, 11:31:30 pm
content: Quote from: lapoltba on December 27, 2015, 03:23:04 pmJust picked up a new-to-me tek 2215 that seems to function perfectly for the small sum of $50. I'll make some adjustments on it and give it a quick tune up and poke around the hameg tomorrow.