Product Support Bulletin 922

COMMERCIAL GOVERNMENT & INDUSTRIAL SOLUTIONS SECTOR PSB # 922
1301 E. ALGONQUIN RD. 
SCHAUMBURG, IL. 60196
(847) 576-0180

APC # 148, 218, 225, 243, 301, 
 360, 409, 448, 482, 509, 
 537, 590, 675, 676, 677, 
680, 743, 

DATE: FEBRUARY, 2000
EXPIRES: N/A

SUBJECT: QUANTAR/QUANTRO MAY NOT RECOVER UPON POWER INTERRUPTION OR POWER LOSS

MODELS AFFECTED:        QUANTAR / QUANTRO (T5365A)
                                                QUANTAR SATELITTE RECEIVERS (T5367A) 
                                                ASTRO-TAC RECEIVERS (T5589A)
                                                ASTRO-TAC COMPARATORS (T5770A)

SYSTEMS AFFECTED: ANY SYSTEM CONTAINING QUANTAR/QUANTRO STATIONS WITH EPIC STATION CONTROL MODULES. 

STATION CONTROL MODULES AFFECTED: 
CLN6686A, CLN6873A, CLN6960A, CLN6961A, TTN4093A-D, TTN4094A-D, TRN7900A-C

SYMPTOM: Upon power interruption the station may not recover and the Fail LED on the front of the Control Board will be on. 

CAUSE: Power loss or power interruptions as described below may cause the above symptom.
Please note this problem will not occur in stations with emergency back up systems such as battery revert.
1) A momentary power loss that induces a power reset but does not fully discharge the power supply for a sufficient length of time (approximately 5 seconds) could cause the above symptom.
2) Stations that are powered off for a sufficient length of time (minute or more) but connected to externally powered peripherals may also prevent a complete discharge of the power supply. A good example of this would be an external high stability 5 Mhz reference.

In either case these scenarios may not allow the PLL internal to the Host Microprocessor on the board to start properly from a known state upon resetting. It may not be possible to determine for certain if the cause of the lock-up is due to the microprocessor state or some other influence such as invalid code plug version, or firmware incompatibility. This particular problem will not be widespread. However, isolated instances may occur.

RESOLUTION: To assure that the PLL will start reliably it is recommended a jumper wire be added to the Host Microprocessor (reference designator U401). A bottom side view, (solder side of the Host Microprocessor U401) is included to aid in identifying the placement of the jumper wire to be added. Looking at the bottom side of the Control Board, orient the Control Board so that you can reference A1 to your lower left. In the following drawing notice the pin identification rows and columns references ( row A -T, columns 1-18 ). 
Add the jumper wire from ResetH ( row M - column 18 ) to TRST ( row L - column 16 ). This will assure that TRST is asserted during reset, also insuring the internal logic of the Host microprocessor is restored to a known state upon reset.

NOTE: If further assistance is required, contact the System Support Center at 1-800-221-7144 and make reference to the bulletin number.


This PSB is for informational Purposes Only.
No Special Reference to Warranty is implied or Intended.