teac 3340 reel to reel problem

mark hansen

New member
has anyone or does anyone know why my 3340 has just lost its ability to produce an output sound level and it lost it's ability to produce a record level, one thing I have noticed is that the 2 relays on the bios board do not energise no matter what mode or switch is used, if anyone has a schematic that they could scan to me, would be much appreciated, looking forward to hearing from someone, thanks, Mark
 
...does anyone know why my 3340 has just lost its ability to produce ...?
Nop.
:)

Mark, could you describe what exactly happening, ala "when I play/record recorded tape and put such and such switches in such ans such position, turn the knob up - this happening (or not happening)...etc"
I assume that you know in general how to use the machine and your setup is right / connections are all ok.
And what exact model of your machine?

Not to say that this has anything to do with your situation, but just in case, this is something I've found in a3340S's pdf as suppliment, see the attached image:
 

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3340 teac problem

thankyou for reply, the machine is the 3340 non "s" model, the problem is that when I want to play a tape, the select sw. set to tape mode, I get no playback signal at all, also if I plug a mic into it, select "source" and turn on "record" red lites are on, I get no record level by speaking into the mic, thankyou for the bulletin on pots, I have the service manual I downloaded, but no schematic was available, I have noticed that the relays on the "bios" board do not energize no matter what mode or buttons I push, thats about the best I can describe this issue,
thanks, Mark
 
Mark, I only have some schematics cuts - digital cam photos of a2340sx machine that SteveM sent me while ago. It's different machine but it may be similar in many ways .
From what you are describing my guess would be that your machine have lost +VDC supply from Power Supply to all amplifiers, this supply also is "firing up" relays on Bias board (there rec/simul/noramal switches are also involved).
I've made photos of the prints I have here and am attaching couple of cuts here, see the picture.
There you see main power supply transformer. Look in the area that I've selected with Red border. What I would do - I'd check the voltage as shown, I don't know for sure what +VDC should be there exactly, but I'd guess it may be +20VDC, maybe more, but you gotta have some positive voltage there of that 'range'.
If you do not have +VDC there, then the voltage regulating circuit's components need to be checked. I would not think that the transformer's section is bad in your situation...
Now if you have +VDC there just fine, then you'd want to check the connectors and leads from power supply to the amp boards and check +VDC on the boards. You need to check both +VDC and Ground Wires and connections!!!!
I am also attaching PSU transformer section as indicated "CANADA". I see there are bunch of fuses there on the secondary from the transformer. So maybe your machine has those fuses there, then you sure simply need to check them out.
Also, I assume that you have some knowledge/experience with repairing electronics, using volmeter etc., and I assume that you have an idea about safety issue and how to work on powered-up equipment without killing yourself or setting the house on fire. Saying it just in case, as it never hurts to mention to someone you talk to for the first time :)
here are the pics:
 

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teac 3340 non S version

does anyone have a schematic on this machine they could share with me,
I cannot get a playback level or record level, no VU meter movement at all
 
Mark, as I've mentioned in the other thread, I've zipped and uploaded the schematics photos that SteveM sent me while ago. this is all I have. It's for a-2340sx machine, not exactly the same as yours, there are must be some differences (regarding to speeds, some transport control , maybe something else?), but for the most it's very similar machine - power supply, amplifiers, record/play switching etc...
Here's the page linK:
http://www.mzentertainment.com/studio_workshop_technical_archive.html
there see "SCHEMATICS, CIRCUIT DIAGRAMS SCANS:" section, it's the first on the list.
You'd need to save zip, unzip it and then print out all the image files and then "puzzle" them together. Kinda' pain in the neck to read, as they are photo-shots of portions of the schematics, but better than nothing. I've bleached some square areas to make files size less and to save some ink when printing, :)
 
sorry to jump on here... but
TEAC A-3340S RECORD RELAY and RELAY CONTROL BOARD

This has been another tape deck nightmare... I always seem to come out of the woods at the end, but when I'm sent out looking, it's pretty bad!
This Teac thing!!! UGH!!!
The one thing I can't figure out is the relay control that attaches to the buttons on the front has a transistor that is shown in the schematic diagram of the PCB as in a totally different place! The PCB is seeming to be the problem, but on this thing I've been down many rabbit holes and came out scratching my head... just glad that I didn't LOSE any functionality for my troubles.

It seems like the K1 relay is not being energized... You can put it into record mode, the lights light up on the individual channels. you can start recording, but it only erases... and it erases rather poorly. If I check the bias amp boards, the main relays are triggered, but the secondary relays aren't... and if I really bury the levels I can even hear a whisper of the signal being recorded (I realize this isn't something i should do often)
Are the secondary relays on those cards for recording. the individual channel ones, triggered by AC instead of DC? Because I can get an AC voltage change if I actively switch them while in recording mode, they just don't move... any of them... and that seems too unlikely, unless they are known for all FUSing together... but I haven't read that.

And curious if the Transistor (d235) is correct? It seems there were a few changes done to this board after the schematic was made... and that makes things all the more difficult in this mess of a machine (with all due respect, I like these machines!) I just can't get this done and i REALLY WANT TO! lol It's so close and I've fixed SO much on this thing... I hate having it all apart and there's so little info in the manuals and the schematics which are outdated apparently before these were even produced.

I have this feeling that maybe it's a matter of voltage not being where it should be, but they don't make the voltages known on any of these... like all of these many many many places you could check... no chance! And someone had to have that info... if there are any voltages and checks i can do at the power supply... OR maybe that VARIABLE resistor that I can't seem to find any reference to in the one power supply... where is the REAL manual?? LOL

I did a lot of testing... and I put some leads on the relay control board, where k1 is located.... and engaged RECORD/pause and the coil for k1 seemed to get energized a little and then fizzled down to nothing... I changed caps, and even some diodes along the way. I even changed D235, because I had that and I didn't realize the schematic and REALITY were divergent... so forgive my installing them on the top of the board... that would have taken a LOT longer to put in the bottom... included a few pics and can send more. I'd like to have this out there, because someone is going to run into this issue, I have a feeling... or already is.

thanks for any help!
 

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