Fuse blows when I put ST 70 on its side

I have a problem with my ST-70. I am rebuilding it and have it finished and want to test the voltages. However with the GZ34 plugged in when I tilt the amp on its side the amp make the sound of a transformer with a large in-rush current and then the fuse blows. I figure the GZ34 must have a loose plate, cathode, etc. I had the tube tested and of course it tested good.

My question, is it possible for this to happen, tilting the amp and a fuse blows. I can turn the amp upside down without the GZ34 and nothing happens.

Thanks again for your response.

Ken

Check your HV wiring after the GZ34.

It can also be a bad output tube shorting when you tilt it, its a long shot but do not disregard it. Without the 5ar4 tube you are not feeding any B+ to the tubes.

Sal

Ken,
Could be a bad tube socket having loose contact with the pins when the amp turned sideways. A good method to support the ST-70 upside down to check the voltages is to remove the bottom cover and then install the top vented cover. Rest the amp on the top cover... Of course...having a top cover would work best.

Kevin