Help with ceriatone 36 watt ef86

[dfarrell]

I just finished a ceriatone 36 watt ef86 a couple of days ago, and it has been working fine, but a bit noisey on the master volume channel. I replaced the wire going from the input to the tube socket with a shielded wire , and when I turned it back on, I got smoke. the source of the smoke was the 1K resistor that runs across the big 32uf/32uf cap. that is mounted on the chassis. The only other thing I did other than change the wire was to discharge the big caps before I started to work on the wires. I did this by running a jumper across the three 22uf caps - that is I hooked my jumper to the positive side and then to the negative side. I am trying to figure out why that resistor smoked. I wonder if I damaged those caps when I discharged them. Can anyone offer some suggestions?

[Colin_D]

Did it arc when you discharged it? That would certainly be bad and dangerous. It's "best" to discharge caps one at a time through a resistor directly to the chassis. That way you know every single one is discharged, and the resistor will keep them from discharging too quickly and causing collateral damage. If you have a bleeder resistor installed it will do this every time you shut the amp off, but you're dealing with dangerous and potentially lethal voltages, so don't rely on it.
My guess would be that the 32/32 uF cap is damaged, but get opinions from guys with more experience than me because a damaged filter cap can take other components out with it.

[dfarrell]

There were no fireworks, I discharged the caps through a resistor.
Even though the resistor across the 32/32 uf cap smoked when I turned the amp on, it still reads 1k ohm across it. I don't know how to tell if the cap is damaged.

[tarzanalog]

Might have just been a bad resistor. I'd replace and power up slowly with a Variac or similar.

[Plexi]

make sure your OT center tap is on the high side B+, if its on the low side, the resistor might draw too much current and smoke. This has happened in some 18 builds we have seen over the years. That would be the first thing to look at.

[I360UP]

I aways put a 220k bleed riz to ground, that way the crct discharges itself.

[Dark1]

Maybe you accidentally caused a B+ related fault when you changed that input cable. Might be worth checking the DC power route for any shorts to earth.
You may find that both the resistor and caps will be fine if you turned it off quick enough.