Portastudio 424 MKiii --> Track 2 does not record anymore

[jurgendeblonde]

I've a real funny situation. I am unable to record anything onto Track 2, no matter what I try. Believe, I tried everything I could come up with. Direct recording, buss recording, different inputs, simultaneous recording on all four tracks and it's pretty undisputable that Track 2 refuses to record since last week.

Playback works, that's not a problem. Meters and input also works, everything works as it should except nothing ends up on track 2 anymore (albeit immensely quiet when I crank levels up to maximum, somewhere in the distance behind the warm hiss, I hear a vague remnant of what I recorded). Meters don't show anything on playback on track 2 either.

I don't know what happened of what causes this and I'm looking for hints or tips.

It's pretty clear that something doesn't come through or doesn't stick to the tape on track 2... so weird and frustrating...

Thanks for any help.

ps: I haven't opened the machine yet

 

[SkywaveTDR]

I have not come across this yet on the bench but a stubborn piece of dirt on the heads will maybe cause this. Then if that is not it and all else works like you say then there is maybe a bad relay or switch that directs the bias to the head- I could not say more without looking into this unit directly. Some of these kinds of things need to be looked into and I would not excuse a broken solder joint as these portable units can be flexed and bounced around but they are not built to take that. Wave soldering which when used with complex boards can represent many opportunities for circuit failures due to broken connection in circuits. Put this kind of product on a space shuttle and probably all circuit would be not working once in space- vibration and heat changes on wave solder boards can render them worthless pretty fast- that is why the product is so cheap.