Author Topic: Technics RS-M260 - no recording/erase whatsoever  (Read 3652 times)

Offline Errilhl

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Technics RS-M260 - no recording/erase whatsoever
« on: November 24, 2022, 02:38:16 PM »
So... I know a little bit about measuring and fault-finding, but I am still a novice, so bear with me.

Symptoms as follows: Everything seems to work - level meters, level adjustment for recording, selector switches, buttons - everything works, clicks etc.

However, when I hit "record" nothing happens. It has a light that is supposed to turn on when recording, this does not turn on. If I go to tape-monitor, it plays what is already on the tape - ie, no erasing what is on there, and no recording of new content.

It has a record mute button - this works (tested continuity while pressed and not) - has no effect on the actual recording (it still doesn't work) - I was hoping this button might've been stuck, but it doesn't seem this is the culprit.

All other functions work fine, play, ff/rew, etc. After looking through the service manual, I found a few test points, which (if I read the manual correctly), should give some voltages when measured. They do not. It is flat at 0, which I assume means they do not get power at all. But that is kinda where my knowledge of reading schematics and such end.

Anyone able to take a look at the service manual, and maybe suggest some things / places I can test measure, to see if I can pinpoint where the problem occurs? Looking at the board / components, I can't see any indicators of anything wrong - caps look good, everything else look good, no burnmarks, nothing.

Nothing gets overly hot either, while it is turned on, so no obvious shorts, it seems.

Service Manual

So, I was hoping someone could point me to some things I can test, measure, etc. Note that I while I do have an oscilloscope, I've never played with it, and know next to nothing about it, so preferably stuff I can do with a multimeter.

Offline quaddriver

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Re: Technics RS-M260 - no recording/erase whatsoever
« Reply #1 on: December 15, 2022, 09:20:18 AM »
when you push record (disclaimer:  I have done a lot of the modern 'Ems' but not that one) does it push a switch with a zillion contacts in it, or is it a soft record button that uses (forget chip registration at the moment) to switch from one thing to another?

if its the switch, drown it in D5 and work it a 100 times.

Offline Errilhl

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Re: Technics RS-M260 - no recording/erase whatsoever
« Reply #2 on: December 16, 2022, 07:35:29 AM »
Ah, it ended up being a wire that had come loose from the record switch, hidden beneath the deck mech/plastic surrounding. Soldered that back on, and now the record bit works, kinda - ie, the recording light comes on. However, something else is broken, since now the level meters go to max immediately, and stay there, and neither play nor record does anything - no sound at all - so the current theory is either a ground issue, a problem with the playback head, or the amp circuit. I haven't had much time to search for the actual problem as of yet, unfortunately.