🚀 go-pugleaf

Thank you for reading this.

My problem is with a US robotics 14400 external modem.

The pcb is marked "1.012.0272-"c and "Model 0272" and connected 5 & 2
for UK use.

The unit I have, has been used in R & D and donated to me without any
connectors, but in a working state ?

However:

The computer side of the modem checks out with things like delrena modem
check
and intels modem test, etc. 

But it fails on phone line pick up, and reports "NO DIAL TONE".
NO tones are apparent at the speaker.

I suspect the speaker driver MC1458 dual opamp.

The opt isolators work and so do the solid (state relays / switches).

My questions then please, are:

Have you a diagram ?
Have you an answer ?

ken @ tbmuk.demon.co.uk

-- 
Ken Hardacre