Many of the phonon lines show short to chassis as soon as we plug the SQUET card, else they are open.

Removing individual SQUETS pointed the issue to the first SQUET, LEDs.

Both LEDs are reading different values. LED1 beeping continuously, LED2 with 2.24V (LED_V_forward).

Removed stages and bring tower to cleanroom for inspecting.

Issue exist at the detector level.

Detector PIN9 (LED2) : Rforward: 105 kohm, Vforward: 2.201 V, Rreversed: 203 kohm

Detector PIN10 (LED1) : Rforward: 32 ohm, Vforward: 0.0015 V, Rreversed: 29 ohm

LED1 is not working but can't find a wire mapping of the detector about which side of the detector that LED is for. Read here: S104 tower installation and detector inspection

From photos, Matt and I agree that Pin 9 is side 1 LED and Pin 10 is side 2 LED.

Two options: setup tower for Side 1 only reading or bonding spare LED on Side 2 (Matt said there are two leds on dib pad)

Himangshu

Shubham

Zach

Elliott

Scott