Portastudio track 2 almost inaudible

[Badmongo88]

Hei i am having a problem with my portastudio which has up to this point been working fine. i was just trying to record some drums on track 2. when there was almost no sound. and it was working just fine days ago with exact same setup. so i try recording on track 3 that worked fine. the meter shows that there is signal and i can hear the audio loud and clear but when recording and playing back there is almost no sound. very low, almost no signal showing on the meter bridge on playback. and what i am able to hear sounds maybe muddier than usual.
Also tried with another tape and still same problem except that it plays back earlier recorded parts on track 2 with no problem
Does anybody know why this is? and if there is a fix?

Any help is a appreciated

 

[A Reel Person]

...

You'd want to start by cleaning the heads.