[solved] Anritsu MS2601B schematics needed (missing horizontal sync) - Page 1
Forum section: electronics / repair

author: carl_lab
author_rank: Frequent Contributor
timestamp: April 24, 2017, 09:24:16 am
content: Couldn't find a schematic on the www, can anybody help please?The schematic I found, is for Hitachi MCL-437F (instead of Sanyo MCL-437F CRT module), but it's a colour TV, so it is useless for me:https://elektrotanya.com/hitachi_chassis_mcl-437f_sch.pdf/download.html

author: dmills
author_rank: Super Contributor
timestamp: April 24, 2017, 12:18:41 pm
content: Seconded,I have one of these with the TG option, but even the user manual seems to be unobtainium.Anritsu manuals have always been a pain in the arse to track down.It is however a fairly straightforward looking design (With some of the biggest DIL packages I have ever seen on the processor and video cards), but I would love to know where they got the neutronium for the chassis, the things are **STUPIDLY** heavy.Experimenting with grafting an LCD in to replace the slightly soft CRT display on mine is on the todo list, I think the video is composite/sync on green. There is (at least on mine) a composite output on the rear panel which could probably be hooked to a scart cable and hence an old telly easily enough to allow you to verify the rest of the thing is working.73 Dan.

author: carl_lab
author_rank: Frequent Contributor
timestamp: April 25, 2017, 11:30:07 am
content: OK, problem solved by following the signal path (without schematics):Someleaking electrolytic capson power supply PCB pissed down some electrolyte to the PCB and to double rowed connector to backplane PCB.Horizontal sync signal is connected through from CRT module over that power supply PCB to backplane.The horizontal sync copper track is etched away just under a leaking 4700uF electrolytic cap.You can see only a dark point on the narrow copper track, but under a microscope you can see it's green copper rust.I'll renew the connector and all electrolytic caps on that PCB .

author: dmills
author_rank: Super Contributor
timestamp: April 25, 2017, 12:14:58 pm
content: I am guessing the guilty party is that board full of electrolytic caps mounted upside down just behind the CRT assembly?I have not managed to get it out of my example yet, lots of screws and I don't seem to have managed to find them all...I am tempted to go thru it and do a recap exercise just as preventative maintenance, just ask me for anything but time.73 Dan.

author: carl_lab
author_rank: Frequent Contributor
timestamp: April 25, 2017, 02:28:53 pm
content: Removing the power supply assembly is quite easy.Remove marked srews (2) and connectors (3+1 for the fan), then pull it out of the backplane connector (maybe some wiggling is necessary).I removed the CRT module before, but I think, you probably can leave it in.

author: dmills
author_rank: Super Contributor
timestamp: April 25, 2017, 04:59:46 pm
content: Interesting, mine looks different to that.The main IF and processor cards are much the same, but I think I may have a full up switcher in place of the transformer (Certainally the caps are in a different location), also the TG version seems to be wider because the IF filter block is mounted beside the RF section on mine. where your IF section is hard up against the side of the box.Amazing the difference you sometimes find in what is putatively the same instrument, I will try to get photos tonight.Regards, Dan.

author: carl_lab
author_rank: Frequent Contributor
timestamp: April 29, 2017, 08:27:44 am
content: Quote from: dmills on April 24, 2017, 12:18:41 pmMS2601Amanuals found at KO4BB (just search for "MS2601"):http://www.ko4bb.com/getsimple/index.php?id=manualsQuote from: dmills on April 25, 2017, 04:59:46 pmDo you have a MS2601Aor a MS2601B?What's the difference between A and B model?