VESTEL 17MB82S, Service Manual

Page: 15 / 64

15
3. POWER STAGE
The DC voltages required at various parts of the chassis and panel are provided by a main
power supply unit. MB82S chassis can operate with
P W05, IPS60, IPS70, IPS16, IPS17,
IPS19, PW25, PW26, PW82-3, PW03, PW04, PW06, PW07 as main power supply and
also with 12V adaptor.
Which power board can be used for board to board or cable connection?
Board to board (BTB) :
PW05, IPS60, IPS70, IPS16, IPS17, IPS19
Power Cable :
PW25, PW26, PW82-3, PW03, PW04, PW06, PW07
The power supplies generate 24V, 12V, 5V, 3,3V and 12V, 5V, 3.3V stand by mode DC
voltages. Power stage which is on-chassis generates 5V, 3V3 stand by voltage and 12V,
8V, 5V, 3V3, 2.5V, 1,8V and 1,2V supplies for other different parts of the chassis. Chassis
block diagram is indicated below.
The blocks on power block diagram is using dependent to main supply. For PW26 and
PW27 just common blocks are enough for proper operation.
Short CCT Protection Circuit
Short circuit protection is necessary for protecting chassis and main IC against damages
when any Vcc supply shorts to ground. Protect pin should be logic high while normal
operation. When there is a short circuit protect pin shold be logic low. After any short
detection, SW forces LEDs on LED card to blink.