51x shorted a lindell pre problem

[okgb]

K, so not me , but a friend was a little careless when putting some modules in his 51x rack
and must have shorted the 16v / 48 rails  and one of his opamps in the lindell pre began to smoke
Upon taking it out the smoked resister measured fine , replaced it anyway , opamp worked in a 312 type pre
but smokes when put back in the Lindell ?  unfortunately they are not socketed , don't have the schematic

there are two opamps , so perhaps something in the other is still shorting

Any idea's ?  I appreciate any tips for direction ,

 

[mitsos]

opamp worked in a 312 type pre .....
but smokes when put back in the Lindell ?

unfortunately they are not socketed.

I'm confused? Not socketed, so how did you test in the 312?
More info, pictures of preamp PCB showing replaced resistor, maybe top and bottom, etc might help.
good luck!

 

[[silent:arts]]

Why do people exchange modules with power on
Put it in, screw it down, and than there is no chance to short anything.
No protection Diodes? +48V to the -16V wouldn't have any harm.

Doesn't help your friend, ignore my rant.
Cheap designed module.

 

[okgb]

unsoldered the opamp , of course [ and soldered it back in ]

 

[pucho812]

unsoldered the opamp , of course [ and soldered it back in ]

while you do that add some socket pins that way you can move them as often as you like. Our SSL 9K t work is the same thing. All soldered in. Everytime we replace an opamp chip, add a socket. really is worth it in the long run

 

[okgb]

I would have done that right away but the existing pins & " through holes " were too small to
put any sockets I had in , as it wasn't mine I didn't want to " bore " the holes , although , I suppose
you could just make sure they were soldered on both sides but then the exisiting opamps may not fit snug .

 

[Sammas]

Why do people exchange modules with power on
Put it in, screw it down, and than there is no chance to short anything.
No protection Diodes? +48V to the -16V wouldn't have any harm.

Doesn't help your friend, ignore my rant.
Cheap designed module.

It has nothing to do with exchanging modules with power on. More so the lack of protection diodes. I had to get an Elysia xpressor repaired twice because the 51x slots allow enough wiggle room to short the pins. Even with the two screws tightly secured... And yes, the power was off when installed.

My solution in the end was to replace the 51x edge connector with a standard api 15 pin.

Problem solved. Though a few extra cents spent when designing the modules would save a heck of a lot of hassle.