Help! Tascam Porta One not Recording! (Red armed recording LED continues blinking instead of going solid after pressing record)

[Zoidburgermon3y]

So I bought this Porta One for $99 bucks in terrible condition. The externals were basically mint but the internals were messed up. The 3rd channel had low volume coming out of it that I discovered, through signal tracing, was due to a shorted cap. The transport was the main issue of the unit. The previous owner had tried restoring it themselves but gave up after saying the transport wasn't working at all. Two of the leaf switches lost their solder connections and I had to re-solder them on.

The auto stop solenoid housing bracket that screws into the transport was installed in the wrong place. I had to move it to free up the record lever and make it move again. The belts had melted off but the previous owner had cleaned them so I put new belts on it. I also had to fix the fast forward mechanism that he removed the gears from. The idler tyre was also not gripping the take-up reel at all and I had to sand up the take up reel and tyre a little bit to make it move again.

After all of this, everything works to my knowledge! Transport works completely mechanically wise and all channels are working as they should!. Going to be replacing the same blown cap in each channels schematic to ensure they don't die as well.

SOOOOOOO now for my issue, the red recording light continues to blink after I press record and no recording is being played down on the tape I am using. I have the tape protection hole filled so that's not the issue. To my knowledge, all of the leaf switches are soldered to the board correctly. I have tried recording on each channels individually and using different knob configurations to confirm it wasn't me that was causing the issue. Any ideas on what you think is the issue?

Now I brought it to a friend's house for a second and I pressed record and the light stayed solid! However when I tried doing it again, it didn't work so now Im thinking its a loose connection in the circuit somewhere. Does anyone have experience with this unit and could help me? This has been almost a month project for me and I am stumped at the moment. But I have been loving every second of the process!

Here are some pics of the unit and my restoration process, there is also a description of the image if you scroll down on the image: https://freeimage.host/a/porta-one-images.P4dMJ

Any help is appreciated thanks!

 

[Jack Saturn]

You mentioned that the Record Detect switch is moving as it should. (The Record Detect switch being the piece of plastic that gets pressed when tabs are still inserted in the cassette shell.) There is also a leaf switch that gets pressed *by* the Record Detect switch, on the rear side of the mechanism. Are the two halves of that leaf switch making good contact? Perhaps one or both inner sides of the switch need to be sanded so they've got good conductivity with each other. This particular switch has been the culprit in a number of cases where I couldn't get a solid red light while in Record mode.

 

[Zoidburgermon3y]

Thanks for the advice! I’ll remember to go back and try sending the pieces, but after re-soldering the same record leaf switch again that you’re talking about, continuity was good after pushing the two leafs together and acting like it was the lever that comes up to push the leaf together when you press record.

this is the correct switch, right? I am attaching an image.

So to my knowledge, it is not the leaf that is causing the problem. Can you think of anything else that might be the issue?

 

[Jack Saturn]

Not off the top of my head. Let us know once you've had a chance to test the switch I'm referring to — and bear in mind that pushing the two halves of the switch together with your fingers is different than engaging it within the mechanism itself. When this particular switch has posed a problem in the past, it's been either because there was corrosion — leading to be continuity — or because one half of the switch was bent just slightly, and wasn't making contact when Record was pressed.