Have you done a complete reset?  There are three levels of reset, but 
the first couple may not do the trick for you.  Try the complete 
reset if you haven't.

At 11:53 PM 3/31/2006, you wrote:
>is your battery supplying enough amperage to put out the full 4 or 5 watts
>on high power?
>Is there a way you can hook it up to a regulated power supply and see if it
>then works?
>Also, you weren't clear in another message as to weather you could receive
>your own signal on the repeater input frequency using another radio?
>Could you hear your own audio on the simplex side?
>Try a test using a simplex frequency like 146.430, set both the th-f6a and
>another receiver on those frequencies, insure that the simplex shift is on,
>or at least, no shift, and see if you can clearly hear yourself on the other
>receiver.
>If so, then the radio is probably transmitting, but isn't transmitting
>enough power to hit the repeater.
>73
>Colin, V A6BKX
>----- Original Message -----
>From: "Matthew Chao" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Friday, March 31, 2006 7:11 PM
>Subject: Malfunctioning THF6A
>
>
> > Hi, Folks!  I seem to be having trouble getting my THF6A into
> > repeaters.  I've reset the rig a few times, checked the input freq
> > and repeater freqs, get a carrier on the input, but can't get into
> > any repeaters.  I've reprorgammed the rig both with the data cable
> > and manually, but no luck.  Any ideas?  How good is Kenwood at fixing
> > my rig in terms of time?  How do I get it fixed?  thanks.--Matt.  (N1IBB)
> >
>
>
>
>--
>No virus found in this incoming message.
>Checked by AVG Free Edition.
>Version: 7.1.385 / Virus Database: 268.3.4/299 - Release Date: 3/31/2006