Reply to thread

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Message: <blockquote data-quote="mThomasDutch" data-source="post: 146935" data-attributes="member: 2616">Hi guys. This one is for the tech heads. I got some weird stuff going on with my RM100 all of a sudden. Was working fine, then it wasn't - as is always the case. So I took it out of it's head cabinet to try a little experiment I was curious about. I flipped it over with the tranny's resting on wood to ensure that the tubes were safe, powered it up and started playing just a little bit at low to moderate volume. In a minute or so I saw a tube failure light go on at tube 4. I assumed it was a bad tube, and I wanted to get on with my experiment, so I simply removed the fuse (it was blown) for that tube and tube 1, halved the impedance at the switch and powered back up. A few minutes later I see a failure light at tube 2. That fuse was also blown. So, I tried a known good set of tubes in all 4 slots - biased them up properly, played a few minutes - at a much more cautious volume now - and another fuse blew. Now, the tube failure light on tube 2 stays lit, even though the fuse is OK, and I can no longer bias the tube all the way up. In it's maxed position on the bias pot I can only get to about 29mA where before it was at 34 long before the max.Any ideas?</blockquote>