V5.0 - 00170 Non-Delivered June 23, 2004

Source:

Naprotek, July 1, 2004

Symptoms:

Probing after reflow identified open between JP9-18 and R95-6.
Naprotek technician confirmed open circuit.

Analyst(s):

Przybylski

Analysis Procedure(s), Findings:

With ohm-meter, confirmed open JP9-18 and R95-6.
No continuity between the top and bottom of the via at R95-6.
Examination under a microscope identified suspicious via at R95-6. Crude microscope pictures taken.

Root cause:

Possibly faulty drilling or PTH plating.

Mitigation:

Board can be recovered with a green wire..
Board will be reviewed by PCB manufacturer.
LBL asks why this faulty via wasn't identified by probing after manufacture.

Disposition:

Awaiting further review by vendor.

Any Other Information:

Not recommended for deployment to Antarctica since a jumper wire had to be added in order to restore full functionality. However, since the repair involves the exernal flasher (not a mission critical subsystem), in a pinch, the board could be deployed.

Pix 1, top of resistor. The problem via is R95.6
Pix 2, the bottom of the board. The problem via is circled.