UNDERSTANDING DEFECT TERMS:
The descriptions below all indicate the particular section which is involved in the abnormality being displayed. Understand that if these lines were only a single pixel in width, then the Panel itself is defective. If the failure is being generated by a PWB and/or a connector, then the line will be at least 8 pixels wide.Address open (line off)
Vertical Influence from the Control,X-Drive Left and Right PWBs and COF.(Note: Defect Line shown is on the front Right, so the X-Drive Left PWB would be involved).
Note: The Screen can be broken down into 7 Vertical Columns. (See the Bottom PWB layout). Each of the connectors from the Control, X-Drive Left and Right PWBs controls each column. Try todetermine which area of the screen is affected to determine the PWB involved. Also, if the COF is defective, the panel is defective and can not be repaired.
Address short (line on)
Vertical Influence from the Control,X-Drive Left and Right PWBs and COF.
(Note: Defect Line shown is on the front Right, so the X-Drive Left PWB would be involved. The Screen can be broken down into 7 Vertical Columns. Each of the connectors from the Control, X-Drive Left and Right PWBs controls each column. Try to determine which area of the screen is affected to determine the PWB involved. Also, if the COF is defective, the panel is defective and can not be repaired.
The figure shows a back view of the Panel.
VERTICAL ADDRESS:
Vertical Addresses is controlled by the COF cables. COF stands for Chip On Film. This means that the Ribbon Cable has embedded IC and resistors.
Note: There are 7 total COF cables controlling the Vertical Addresses. They are broken down into 2, 3, 2. The 2 on the left are controlled by the X-Drive Left PWB, the 3 in the middle are controlled by the Control (LVDS) PWB and the 2 on the right are controlled by the X-Drive Right PWB. The Figure below shows one of the COF cables. Note the chips, capacitors and resistors mounted on the flexible ribbon cables. Also note there are 4 COF per cable. (4 X 7 = 24 COFs). 4 Per cable, 7 Cables.
COF (Chip On Film Cable):
Supplies a waveform which was generated from the Control PWB to the panel and selects a output pin that is controlled by COF (Chip On Film) when it will be on or off. 96 output pin per COF IC.
The higher the resolution, the less spare space where an IC can be placed on the PWB without using IC PACKAGE, so a BARE IC is used embedded right on the cable.
Because IC is not soldered on PWB directly, soldering defect rate is decreased. COF failure requires Panel replacement.
HORIZONTAL ADDRESS:
Horizontal Address is controlled by 6 Printed Circuit Cables. Supplies a driving waveform to PANEL by connecting a PAD electrode of PANEL with PCB
(Y Drive and Z SUS).
There are two types of this for Y Drive PWB. One is single-sided, another is double-side. These have a pattern on it .
For Z SUS PWB, there is no pattern , single-sided and Beta type (all of copper surface).
For connecting a Logic signal between PWBs. The one shown here is P101 from the Control PWB to the Y SUS PWB.
There is 0.5mm pitch, 50 pin type and; 1mm pitch , 30 pin type.
