Hey hey, quick Q, BLOWN Linear Regulator... yeah, blown wide open

Ok, I had a 40v In, 8v Out, 1.5A Linear Regulator blow WIDE OPEN in a power supply this weekend.

To be fair, I have a master section issue where Bus's 3-8 are quiet and distorted, still working out the cause (And now benching the master seciton, thinkin the bus issue may be opamps... I have replacements on hand)

Also, I would get periodic Meter Spikes.... one every few minutes across all 32 input meters and stereo VU's

But, the board was only powered up for about 1 minute this time and SNAP!!!!!

Heard a crack/snap/pop in the PSU....

Powered her down immediately, and the regulator was physically blown wide open, cracked in half, one pin and a chunk of plastic hanging off to the side.

I've never seen this before. Ever... even in bad regulators, never seen one blow open.

The 8v is fed to the meter bridge, master section, and down the bus pcbs.

just tearing into these last issues and my custom monster 56 channel 16 bus is finished

Anyone ever seen this?

Apparently something shorted?

Or is it possible that the regulator was on it's way out, causeing the above mentioned issues, and finally went?

I guess just mostly wondering if this was possible that the regulator was on it's way out, and that's why it went like this....

Any take on it would be cool... (The regulator itself, not like I'm asking what's wrong with the board, just to be clear)

Fun one too.... apparently this is not a very common spec regulator, everyone but the console manufacturer was backordered, so my $.75 cent Regulator cost me $3.49 each (Bought two) plus shipping, RUSH shipping

Shorty said:

But, the board was only powered up for about 1 minute this time and SNAP!!!!!
Heard a crack/snap/pop in the PSU....
Powered her down immediately, and the regulator was physically blown wide open, cracked in half, one pin and a chunk of plastic hanging off to the side.
Anyone ever seen this?
Apparently something shorted?
Or is it possible that the regulator was on it's way out, causeing the above mentioned issues, and finally went?

Click to expand...

Sounds like a thermal problem if it took a minute to pop.
Yes I've seen this on some regulators where they don't have any thermal protection and insufficient or poorly attached heatsinking.
You may be using the regulator too close to its design limits, since you have not mentioned the regulator type or the load characteristics it is hard to determine.

Shorty said:

Ok, I had a 40v In, 8v Out, 1.5A Linear Regulator blow WIDE OPEN in a power supply this weekend.
...32 input meters

...The 8v is fed to the meter bridge, master section, and down the bus pcbs.

custom monster 56 channel 16 bus

Fun one too.... apparently this is not a very common spec regulator, everyone but the console manufacturer was backordered, so my $.75 cent Regulator cost me $3.49 each (Bought two) plus shipping, RUSH shipping

Click to expand...

Seems to me that the power consumption may be quite high on that 8V rail. Did you measured it with an Amp-meter?
Must be be quite a hard task for a $0.75 regulator... Especialy with 32V to drop! Which model is it? Package? Heatsink?

You said the console is a 'custom monster'. If you added modules that draws current on the 8V rail, maybe you exceeded the maximum?

Axel

Show a schematic--how should we otherwise help? 50 W power dissipation is possible for some regulators, but you'll need a serious heatsink. Also 32 V in-out voltage difference is close to breakdown for most parts.

Samuel