ringading
Well-Known Member
I know we all like to provide our success stories here to help others working on the same equipment. But here is one of my @#$%^%$^ mistakes.
Got a 2220B off CL with a cut power cord. New cord was installed and turns out it worked.
So I was recapping the main amplifier board and well, put a cap in backwards . And of course I wasn't using my DBT as I recently moved my work area and haven't hooked up everything yet. The cap I had backwards was C719 220uf/50v. It fried the R765 22ohms/1/4 watt resistor but nothing else that I can spot visually.
Replacing the resistor is easy but I am unsure of what else to check - maybe R757 and H723? I haven't had this happen before so am unsure of how pervasive the damage may be. It was on for only a couple of seconds but that probably doesn't matter as the damage can be done in fractions of a second.
When resistors go poof like this one did, I imagine it shorts the circuit but there could have been damage downstream in the brief time it took to surrender and put up its smoke signals.
Got a 2220B off CL with a cut power cord. New cord was installed and turns out it worked.
So I was recapping the main amplifier board and well, put a cap in backwards . And of course I wasn't using my DBT as I recently moved my work area and haven't hooked up everything yet. The cap I had backwards was C719 220uf/50v. It fried the R765 22ohms/1/4 watt resistor but nothing else that I can spot visually.
Replacing the resistor is easy but I am unsure of what else to check - maybe R757 and H723? I haven't had this happen before so am unsure of how pervasive the damage may be. It was on for only a couple of seconds but that probably doesn't matter as the damage can be done in fractions of a second.
When resistors go poof like this one did, I imagine it shorts the circuit but there could have been damage downstream in the brief time it took to surrender and put up its smoke signals.