Dell P780, Sony Chassis D99 No G2 voltage.

[David]

Please see 112Kb binary file in sci.electronics.schematics if you need
to see part of the schematic.

Here is what I have, several of the P780 monitors with no G2 voltage.
Following all the way back to IC001 the G2 output control pin has only
1.0 volts on it. 12V and 5v are good, the sync to the IC001 are good,
sda and scl show data at 5v peak.
The 2.2Mohm resistor on the 1.2KV line is good.
Q001 reads 4.9v on the base, 5.5v on the emitter, essentially no
voltage on the collector (actually reads something like 6.5 volts).
I do not have access to Sony DAS alignment software to even see if the
G2 control is adjustable.

Pulling Q001 out gives a bright with retrace screen with a washed out
and smeared image.

I have it narrowed down to the IC005 (NJM4558), IC001 (CXA2067S), or a
corrupted data stream going to IC001.

Has anyone else repaired similar problem on this or similar Sony
chassis?
If so am I overlooking something, every resistor, diode, and the
transistor test good with proper equipment.

I do not want to replace IC001 only to find out something else was the
problem.

Thanks for any help.

FYI my email address that will get through to me is rdkuhajda (at)
locl.net. Otherwise please post to the group so the information can
be archived for others with the same monitor.

David

 

[DAEWOOsSUCK]

Just thought y'all would like to know that it is confirmed an eeprom data
problem. The only way to fix is with a new eeprom and the Sony DAS
software. Guess it is time for the trash bin on these as the cost of the
software and jigs far exceeds the value of the 4 monitors combined.

I pulled an eeprom off a physically broken unit and put it on one of the
boards and the monitor came up, albeit with very poor gray scale and
geometry base settings.

David

 

[dkuhajda]

Just thought y'all would like to know that it is confirmed an eeprom data
problem. The only way to fix is with a new eeprom and the Sony DAS
software. Guess it is time for the trash bin on these as the cost of the
software and jigs far exceeds the value of the 4 monitors combined.

I pulled an eeprom off a physically broken unit and put it on one of the
boards and the monitor came up, albeit with very poor gray scale and
geometry base settings.

David