Problem with Urei silverface LA-4

[sonichermit]

Wondering if anyone has any thoughts on this. I have a pair of Silver Urei LA-4's, both modified with Eddie Cilletti opamp mods and have worked for years. Several days ago one unit is no longer working. VU meter indicator all the way to the left in GR position. No signal is passing either. Other unit is working fine, VU indicator is supposed to be on 0 with no signal present in GR position.. Wondering if possibly the opto coupler is dead or if it is something else. I was running bass signal out from a UA 2-610 into the LA4. Could it be I overloaded the input on the LA 4 and blew something out? Any help much appreciated. Email at [email protected]

 

[PRR]

No meter, no signal, I would start at the BASIC. Is there power inside? Like 300V DC and 6V AC?

 

[Rob Flinn]

No meter, no signal, I would start at the BASIC. Is there power inside? Like 300V DC and 6V AC?

I thnk you mean + & -15v.  The LA4 isn't a valve unit.