Fostex e-16

[PabloMilion]

I have a Fostex E-16 that was working ok for years but few weeks ago 8 channels stoped working (Ch: 9-16). Unable to record and play. I can see input monitoring all 16 channels but not able to record. All the voltage regulators at the top of heat sing been replaced.All power suply board electrolytic capacitors replaced to.Other 8 chanels (1-8) works fine.Heads in good shape.

I would appreciate any help.

Thanks

[jamesperrett]

Why did you replace all those parts?

Can you play back previously recorded tapes? If you don't have any other tapes then what happens when you play tapes with tracks 1-8 recorded in the reverse direction?

Are the heads and guides scrupulously clean. Are you trying to use Ampex tapes?

[PabloMilion]

I came acros a post that this might be a problem with the power suply.I found some leaks under the caps so i thought replaceing them would be a good starting point but i was wrong

I can play some old tapes but only hear 1-8 chanel and so sound from 9-16
All the heads and guides cleaned and demagnetized.

Audio interface shows around -60dB input and i can hear very low sound coming from 9-16

[jamesperrett]

Can you hear the input monitoring through those channels?

Are you using a 16 way loom or 2 8 channel looms? If it is the latter then could the loom be faulty?

If the meters are working then the signal is getting most of the way through the circuit as the Dolby chip is always in the signal path. Have you compared the voltage on the mute pins on the faulty channels to the same pins on the good channels? The mute circuit appears to be the only thing that would stop audio passing when the meters are registering.