BVDC Bias Voltage Distribution Card Inventory --------------------------------------------------- Original Rev. 2-FEB-2008 Current Rev. 21-MAR-2008 This note is an inventory of the BVDC cards including information about their current location and status. There different types of BVDC cards were built: pre-production physical model only, hand assembled production, and full production BVDC cards. Pre-Production Physical Model Only ---------------------------------- Two of these cards were made, one inner wireframe card and one outer wireframe card. These cards are not electrically functional. They are "quick turn" physical models only. They were delivered to Fermi on 19-NOV-2007. Hand Assembled Production Model ------------------------------- Two of these cards were made, one inner wireframe card and one outer wireframe card. These cards are fully functional but they were assembled by hand using rosin core solder and not cleaned. So they have different contamination problems in LAr than the normal series production BVDC cards. These two hand assembled BVDC cards should not be used in the T962 TPC but they could be used for other test systems. They were delivered to Fermi on the 16:18-Jan-2008 trip. Production BVDC Cards --------------------- A total of 30 series production BVDC cards were made. 13 of the production BVDC cards were built with horizontal entry connectors and are thus for use on the inner wireframe. These cards have serial numbers 1:13. 17 of the production BVDC cards have the vertical entry connectors and are for use on the outer wireframe. These BVDC cards have serial numbers 14:30. If you look at the BVDC card, component side up, with the Bias Voltage input connector edge closest to you, then the serial number is located in the lower left-hand corner. Notes on specific production BVDC Cards: ---------------------------------------- SN# 13 has a number of problems and must not be used. The 50 pin header is not soldered on flat. The pin 50 end of this header is way up off of the board. All of this headers solder connections to the board look OK. It is at least far enough in so that its pins are coming through the solder side of the card but it had another problem. Wire signals 2 and 3 do not make it from the low side of the DC blocking capacitor to their pins in the header. I do not know if the problem is broken traces or what but there is clearly and open circuit in these signal paths. SN# 16 The 50 pin header of this BVDC is a little up off of the card. It's not bad, and the card tests OK but we might as well not use it unless we need it. SN# 22 This board is warped along its front edge where the connectors are that go to the wireframe. It's not bad, and the card tests OK but we might as well not use it unless we need it. Production BVDC cards delivered to Fermi: ----------------------------------------- On 14-FEB-2008 BVDC cards SN# 1:10, 14, 15, 17:21, 23:30 were delivered to Fermi, i.e. 10 BVDCs for the Inner wireframe and 15 BVDCs for the Outer wireframe were delivered to Fermi. Remaining here at MSU on 14-Feb-2008 will be: SN# 11 tested good inner type BVDC SN# 12 tested good inner type BVDC SN# 13 bad inner type BVDC - no connections for wires 2 and 3 SN# 16 tested good Outer type BVDC but its 50 pin header is up a little at one end SN# 22 tested good Outer type BVDC but it is warped along its front edge Testing Procedure: ------------------- Equipment used: Krohn-Hite model UHR-220 power supply 0-500 Volt Neon lamp test jig made for testing the BVDC cards 50 pin shorting plug Work on 21-MAR-2008 BVDC SN# 13 --------------------------------- Investigate the problems with BVDC SN# 13. There are in fact many opens between the preamp side of the DC blocking capacitor and the 50 pin header. It appears that there is an open in this circuit for BVDC wire numbers: 2, 3, 5, 6, 7, 8, 10. This is almost all of the wires on one side of the BVDC card. Pull off one of the DC blocking capacitor and the open circuit is not an open in the tunnel of the capacitor low side via. The open does not appear to be in the 50 pin header via because I can see solder on both the top and bottom pads. So the open must be in the trace. It is most likely a scratch in the etch resist on just this card and thus the rest of the BVDC cards may be 100% OK. On the bottom side add jumper wires from the DC blocking capacitor low side to the 50 pin headers for BVDC wire numbers 4:12. I still need to add jumper wires to repair BVDC wire numbers 1:3. Make more modifications to BVDC SN# 13 so that the 32 Channel Pulser can be plugged into it. For now the 32 Channel Pulser connector is wired into the BVDC card in a way that fires the signals in PFC-16 card channel order.