Hi Nils,

Turning off after a couple of seconds usually means it's not
communicating with the head, or there's something wrong with the EPROM,
or there's something wrong with the power source (or in-line fuses).

Do the usual checks - un-plug and re-plug all the cables and fuses,
remove the lids and re-seat all the socketed IC's and all the connectors
between boards and other connectors.
Check carefully for any bent connector or EPROM pins.
Make sure it has at least 12 volts at the fuses.

The microphone should have nothing to do with this problem.

73,
Mark

-----Original Message-----
From: FM900@yahoogroups.com [mailto:FM900@yahoogroups.com] On Behalf Of
Nils
Sent: Monday, 29 June 2009 08:03 PM
To: FM900@yahoogroups.com
Subject: RE: [Fm 900] 91R switches on and a sec later switches off...

Hi all,

Have been observing for some yrs and think the last time I posted a
message
was maybe 5yrs ago..lol till now..

I dug up my old 91 out of retirement and found it has stopped working.

Was working fine 4-5 yrs ago but now when I attempt to get the old girl
going it lights up and displays 88888888 like a test as I remember and
within a sec or so switches off.

Tried 3 different mikes. 1 x rear plug then 1 x front panel and finally
a
duplex handset. Made no difference just shuts down.

Could it be the jolly green cap near the power input side of things??

I look forward to a positive reply from the group.

Kind Regards,

Nils Eriksen J