Anyway to fix a broken 4th track?

[deepfrybonanza]

After over a year of happy, productive use the other day my Tascam Porta 02 MKII stopped being able to record to the 4th track. I opened the unit up to see if I could find the source of the problem, but nothing was obvious, i.e. no severed or loose wires, etc. Does anyone know how to get the unit working properly again? I gather this is a relatively common problem, so are there any quick fixes?

[krhall]

Ok 4 things you should rule out before deciding to take it to a repair store.

1. Have you checked to see if there is any oxide deposits on the head surface.

2. Have the heads become misaligned (ie: bleedthrough on tracks 1 to 3 or maybe even intermitent dropouts)

3. Is there any output at all from track 4 (ie: very quiet muffled sound - you may have to turn up the volume to hear it.

4. Have you been demagnetizing the tape travel path and tape heads after every 8 hours running time.

Hope this may help

Keith