Svt 400T preamp not working

[omen400textreme]

Hey all,
I have a svt 400T that the preamp isn't working.
Any tips on where to start? Is this a common issue with these? Any help would be appreciated
Thanks Merry Christmas and happy new year

 

[omen400textreme]

Edit: got it to function using a patch cable From preamp out to power amp in. Checked all the fuses. Works for now, but would like to get it back to normal. Thanks

 

[Jim C]

Often times, using a cable from pre-amp out to power amp illustrates that there is a bad connection in these jacks. Many recommend only using a cleaner called Deoxit with the tiniest bit applied to a 1/4" plug (end of a guitar cable) which is then inserted into the jack and removed (a few times). Wipe the plug with a clean cloth and repeat. Then do the same with the other jack.
CAIG Laboratories DeoxIT D5 Contact Cleaner 5% Solution - 5-oz. Spray

 

[beans-on-toast]

There’s a shunt, a switch in the jack, that the Deoxit would need to clean. When oxidized, the shunt does not make a good contact.

 

[omen400textreme]

Hmm. Ok. That makes sense. Thank you