My Applevision 1710 monitor has intermittant problems. At power up,
sometimes the monitor displays normally after a few seconds, sometimes
it displays after 3 to 10 minutes and sometimes the screen remains
completely black.
I have read the recent news from Zeljko but i need more help.
From my reading of the news, i suspect 3 sources of problem:
1/the opto-isolator (Motorola MOC2A60-5)
2/the PTC thermistor RP49 (i have read on the news that it is a PTC
type, is it a PTC?)
3/loss of the parameter settings in the processor of the CRT video board
1/ opto-isolator Motorola MOC2A60-5
Is it possible to short (pins 7-9) it definitively and switch off the
monitor by switching off the main power on the monitor?
In this case, the energy save feature uill not work. Do i will be able
to use the monitor?
The LED cathode and anode are respectively 2 and 3 (close). The load is
between 7 and 9 (rather distant).
2/ PTC thermistor RP49
I measured on mine a value of 1100 khoms. On Anatek i found it should
have a value of 4.8 to 5.4 khoms at romm temperature.
Is it correct to replace the thermistor by a standard 4.7 khoms resistor?
Where are the square blue J29P190 PTC thermistor and TL431 mentionned
by Zeljko ?
I have made a picture of the Applevision main board, showing the
opto-isolator MOC2A60-5, the thermistor RP49 and IC TDA4605.
(
http://pbrosson.free.fr/applevision/mainBoard.jpeg)
3/ reconfiguring the CRT video board parameters
I'd like to reconfigure the CRT video board parameters with Apple's
Display Service Utility (DSU) software
Apple's DSU requires that a jumper (Apple part number 076-0529) be
placed in a 4-pin connector labelled BV1.
Apple docs indicate that only 2 pins need to be shortcut, but does not
say which.
I have numbered these 4 pins, please have a look at the picture of the
CRT video board with its 4-pin BV1 connector at :
http://pbrosson.free.fr/applevision/jumper.jpeg
Looking in detail at the CRT video board, i found that
pin 1 is not connected to any thing
pin 2 is connected to pin14 of IV2 IC, to pin4 of IV4 IC and to pin39 of
IV6 IC
pin 3 is connected to pin12 of IV2 IC and to pin10 of IV6 IC
pin 4 is connected to pin12 of IV6 IC
I could try to short 2-3, 2-4 or 3-4, but i am afraid of damaging my
monitor, so any information is *really* welcome.
4/ Where i can find the model reference, pin designation and datasheets
of these ICs of the CRT video board?
IV2: 28 legs, with this label
Motorola
LSC 442 025CDWR2
341 S0296
6D56GLLGG9649
IV4: 8 legs, with this label
4LC21
M /SN
IV6: 44 legs with this label
Motorola 3415
0287
V3.01
LSC438802B
341S0288
Links
Apple Display Service Utility(4.2.1):
ftp://grijan.cjb.net:21000/macintosh...rvutil.sea.bin
AppleVision service manual:
http://preterhuman.net/texts/computi...av_display.pdf
Datasheet on MOC2A60-5 opto-isolator:
http://www.dialelec.com.
Anatek:
http://www.anatekcorp.com
Thank you very much for your help.
Philippe