Messed up my Tube Screamer a little... LED issue

[gbkd80]

I was hoping I wouldn't have to even post once about this, but the other day I chip-swapped my 808 reissue with a socket and an original 4558D I had hanging around, just to see the difference.  Well, I noticed the difference.  Sounded less murky, etc.  Put it all back together and it works, but the LED is burned out.  I took everything apart and I'm measuring 9v at the LED... that doesn't sound right.  I tried connecting a good LED to the board with jumpers but that won't work either.  So I'm assuming I shorted something out on the board when I swapped the chip?  Like I said it works fine.  I checked all the resistors on the side near the chip to make sure they weren't shorting.  What voltages should I be getting at the LED anyway?

[gbkd80]

I removed the old LED board from the equation and the new LED is ok... but am I really supposed to be getting 9v and 7v on the LED?

[PRR]

> 9v and 7v on the LED?

9V one side 7V the other seems right. The LED itself only feels 9V-7V= 2V, and 1.6V-2.9V are typical LED voltage drops. The other 7V is presumably dropped in a resistor. Which apparently runs to ground.

[gbkd80]

Cool, now I understand that.  Thank you!  Still not sure how I managed to burn out the LED, but whatever it's fixed!