Fender Hot Rod Deluxe problem. Only one 6L6 glows, swapped tubes, left-hand one still no glow. Brittle, bad sound. Just a player, not an amp guy! Thanks.

An internal component has failed. Without it in front of me for testing I cannot say which. You need to takje it to the repair shop.

Unless the person that analyzed this problem used an oscilloscope and did detailed troubleshooting, I would NOT jump to the conclusion that aan op amp was blown BASED upon my looking at the schematic of the unit. There are MANY components involved with the overdrive channel, including relays and other transistors and components. The most probable caause would be that 1/2 of the V2 vacuum tube is burnt out. Test by swapping V1 with V2. If NOTHING works, then replace the tube that is NOW in V1 as the second section of it has a burnt out heater. Also a bad potentiometer for the OD channel would be a suspect. A VERY common problem is broken solder at pot terminals. Try plugging a set of headphones into the preamp output. See if you can hear sounds in bothe OD and clean channels. Note you will only hear sound in the LEFT headphone as the preamp out is MONO. MOST of the three op amp chips would NOT kill the OD signal if they were bad.

If it is new then something is a bit strange to say the least. Turn all the knobs to midpoint. If it is going to click/pop then you will definitely hear it. Switch to standby, then power to on for a minute then standby to on. You should then see the 6l6 and the 3x 12AX7's all glowing. Plug into each channel. Don;t use a pedal to try any of this. If you get a pop on on ch then it can be one side of the preamp either a tube or one of the op amps on the board.

Make sure you try out the cable/guitar on a different amp to make sure it is working. Could be a cable or plug that is the problem.

Honestly if this is new I'd haul it back to the store and return it. It should just work with no hassles. Once you know your guitar/cable is not the cause then I would take it back and get them to either set it up or replace it. Something is just not right here for a brand new amp.

Had this happen once, maybe the amp module is fried... if thats the case, you might need a new one.

Are fuses OK?

Not knowing which of the tubes in the unit you are talking about we can't give you help. Usually a "pair" is used for the power output tubes like the 6L6's, but this has 12AX7's as well.

If you are talking about the 12AX7's, they have TWO sections in each tube, and depending where you swapped them, one section could be out and the unit APPEAR to work, although there would likely be some feature that did not work properly.

IF the ones you swapped are the big 6L6's and one way works and another doesn't, you have BIG problems possibly involving blown output transformer and one blown tube.

If it worked before you changed the tubes, it is possible one of the replacements (probably a small tube) was bad... it happens... Another possibility is that a socket pin has gone bad or a pin has broken or bent off... again probably one of the small ones... 12AX7/12AT7 or equivalent.
Swap old ones back in one at a time.

Hello. You might have a "Tube rattle" problem. This is very common in these amps.
google "tube rattle" and you will find alot of people having the same issue.
There is some rubber tube dampers that you can buy to stop the rattling.
Hope this will help

/Daniel

Fender hot rod´s have an common problem on the plate resistors of the preamp and phase inverter tubes.

Check if the 100K and 82K resistors on the tube socket board are not brown. Those resistors usually need to be changed to bigger ones 1/2W.

this guy made a good document about this fix:

http://home.comcast.net/~fredholz/Justin-Holton/Fixing%20Loud%20and%20Intermittent%20Crackle%20or%20Static.pdf

More than likely a bad solder joint. Where is the next question. How confident are you with voltage measurments? The rails in tube amps are high and can kill you so if you are not inclined to do so please don't. The reason I suspect a solder joint is that it is a failure over time, cold solder joints expand and contract with heat. When they heat up they break connection. Not saying 100% that is your problem but it is very likley.

Ah yes, the Fender Hot Rod Deluxe. I have seen more of these in my shop than any other amplifier!! I have even sent recomendations for design changes to Fender about this amplifier.
Sadly, your amp tech may be correct: while the amp is within working specs, you can still have an issue with a bad socket. The cheapest thing to try is to replace the preamp tube(s) you think may be causing the problem. If the problem persists, it may need to be serviced on this issue (by a different 'certified Fender tech'). In defense of the last tech you had work on this amp, these amplifiers have a brittle design and do not gig or travel well (there are a minority of these amps made that do perform). Fender tried to do too much for the price on this model: best advice is to fix it, sell it and get your tone with a more stable model made by Fender (like the new vintage re-issues). Fender, like Marshall, has for years been having problems when they get too far from thier 'working reciepe' of what made them great companies.
You likely have a socket that needs re-tensioned, or a preamp tube not behaving. If it is not these, then a tech had to dive in the house of cards that is this circuit. Sorry for the bad news on this, but it is the truth. I only take on Hot Rods that 'appear' to be fixable. I am a development engineer, build amps from scratch and fix them for the local music shops, and my success rate is a dismal 60%-ish percent on these...
Thanks,-mike