I own a Trace Elliot V4 1x15 combo, the later version with many preamp valves and the magic eye. Anyway about a month ago was about to play a gig when one of the four KT88's (Ruby) went blue and blew one of the power valve fuses. During the next week I replaced all of the valves with NOS (80's?) Sovtek KT88s. I replaced both of the valve fuses. Power comes on but NO SOUND. After advice from other sites and fellow owners I replaced both of the main fuses, (located inside) and the two fuses (6 in all !) under the mains input. I also replaced all of the ECC83's with known working ones (each checked in a Super Champ). STILL NO SOUND. The speaker is connected, it is an Eminence Legend, lightly used. I have since taken the combo to a tech who is taking a long time to fix it, meanwhile I am sitting here thinking A) Does this bloke know what he is doing B)Maybe I could have diagnosed it myself. So my questions are, would a faulty EM 84 valve cause no sound? (surely not as it's an indicator) , what are the chance of a less than year old Emi Legend blowing and causing no sound ? Has anyone else experienced complete loss of sound in this model or similar ? I should mention, I biased the new power tubes, The EM 84 is lighting up white (should be green). All of the valves, pre and power have glowing filaments. The power valve fuses are fine, there are no signs of excessive heat problems, the fan is working, and the amp turns on as normal (power is going through). Thanks in advance for any help or suggestions. Cheers.