Lightning Damage
Every year a number of HomeVision units are damaged by lightning strikes. This
isn't surprising considering the many wires that users typically have connected to
HomeVision. These wires, which often run long distances through the home, can easily pick
up voltage surges induced by nearby lighting strikes. While a UPS or surge suppressor may
protect against surges on the AC power lines, wires connected to serial ports or digital
I/O lines are unprotected.
The most frequent damage occurs to the HomeVision serial port. This usually
results in the inability of the PC to communicate with the HomeVision controller, although
other HomeVision functions are usually not damaged. It is also common for the digital I/O
lines to be damaged.
Users may return a damaged HomeVision unit for repair. However, since lightning
damage isn't covered by the warranty, there is a charge for this. This also results in
several days of downtime while you wait for the repaired unit. Therefore, you may prefer
to repair the unit yourself. In most cases of lighting damage, only the interface chip(s)
are damaged. These chips are in sockets and are easy to replace. Our
troubleshooting web page explains how to isolate most
failures to the faulty chip. Once you know which chip is faulty, you can obtain one from a
variety of sources. The next section provides part numbers from three popular electronic
parts distributors (DigiKey,
Mouser, and Jameco).
Recommended Spare Parts
Rather than waiting until damage occurs, you may prefer to purchase a handful of
parts in advance. That way, you'll be able to immediately repair the damage.
Following are recommended kits of parts you may want to have on hand.
Recommended spares for HomeVision or HomeVision-PC
unit:
Replacement Parts List
Note: Prices shown were obtained June 2003 and
are subject to change.
RS-232 Serial Interface Chip
Where used: HomeVision, HomeVision-Pro, HomeVision-Serial, and HomeVision-Phone/Serial
RS-232 serial interface
Manufacturer part numbers: MAX232CPE, SP232ACP, ICL232CPL
Distributor part numbers and typical prices:
DigiKey MAX232CPE @ $3.31
Jameco 24811 @ $2.19
Mouser 570-ICL232CPE @ $ 2.45
RS-485 Serial Interface Chip
Where used: HomeVision-Pro and HomeVision-Serial RS-485 serial interface
Manufacturer part numbers: MAX489CPD
Distributor part numbers and typical prices:
DigiKey
MAX489CPD @ $2.81
74HC573 Input Latch
Where used: Multifunction Expansion Board ports 2 and 3; HomeVision-Pro Port C LEDs
Manufacturer part numbers: 74HC573N, MM74HC573N, TC74HC573AP, SN74HC573AN, M74HC573B1R
Distributor part numbers and typical prices:
Jameco 46076 @ $0.69
DigiKey MM74HC573N @ $0.72
DigiKey TC74HC573AP @ $0.64
DigiKey SN74HC573AN @ $0.49
Mouser 512-MM74HC573N @ $0.54
Mouser 511-M74HC573 @ $0.70
74HC4053 Multiplexer
Where used: HomeVision-Pro and Multifunction Expansion Board digital temperature sensor
interface
Manufacturer part numbers: MM74HC4053N,
TC74HC4053AP, M74HC4053B1R
Distributor part numbers and typical prices:
DigiKey MM74HC4053N @ $0.67
DigiKey TC74HC4053AP @ $0.72
Mouser 512-MM74HC4053N @ $0.50>
Mouser 511-M74HC4053 @ $0.84
1489 Input Receiver
Where used: HomeVision port B, HomeVision-Pro port B, Multifunction Expansion Board port 1
Manufacturer part numbers: DS1489N, MC1489N, MC1489P, LM1489N, DS14C89N
Distributor part numbers and typical prices:
DigiKey DS1489N @ $0.58
DigiKey MC1489N @ $0.48
Jameco 23181 @ $0.24
Jameco 16379 @ $0.65
Mouser 511-MC1489P @ $0.28
ULN2803A Driver
Where used: HomeVision Port A, Multifunction Expansion Board IR zones output
Manufacturer part numbers: ULN2803A, ULN2803AP
Distributor part numbers and typical prices:
DigiKey ULN2803AP @ $0.72
Jameco 34315 @ $0.69
Mouser 511-ULN2803A @ $0.44
PCF8574PN
Where used: HomeVision port C, HomeVision-Pro port C, Multifunction Expansion Board
(controls all input ports)
Manufacturer part numbers: PCF8574PN, PCF8574N
Distributor part numbers and typical prices:
DigiKey PCF8574N (or 296-13109-5-ND) @ $1.88
PCF8591PN
Where used: Multifunction Expansion Board and HomeVision-Pro analog inputs
Manufacturer part numbers: PCF8591PN
Distributor part numbers and typical prices:
DS80C320 Processor
Where used: HomeVision and HomeVision-Pro processor
Manufacturer part number: DS80C320-MCG
Distributor part numbers and typical prices:
DigiKey DS80C320-MCG @ $14.84
Jameco 114403 @ $14.95
Resistor network, 2.7K
Where used: Multifunction Expansion Board port 1
Manufacturer part number: 4116R-1-272 (there are also others)
Distributor part numbers and typical prices:
DigiKey 4116R-1-272 @ $0.60
Mouser 4116R-1-272 @ $0.49
Resistor network, 100K
Where used: Multifunction Expansion Board ports 2 and 3
Manufacturer part number: 4116R-1-104 (there are also others)
Distributor part numbers and typical prices:
DigiKey 4116R-1-104 @ $0.60
Mouser 4116R-1-104 @ $0.49
Jameco 108644 @ $0.49
