Read Sharp 28HW-53 (serv.man9) Service Manual online
9
28HW-53H
G2, Cut Off and Gain Adjustments (alternative method).
In the event off a Colorimeter not being available, please follow the following procedures to obtain correct G2 and Grey
scale settings.
scale settings.
1. Tune the set to the output of a RF signal generator (cross hatch pattern).
2. In the user menu, set the picture levels to the FACTORY settings.
3. In the user menu, set the tint control to its central position.
4. Enter the service mode.
5. Set the ABL levels in the NVM by adjusting positions 60, 61, 62, 63, 64 and 65 on page 00 to read 80. Store each
2. In the user menu, set the picture levels to the FACTORY settings.
3. In the user menu, set the tint control to its central position.
4. Enter the service mode.
5. Set the ABL levels in the NVM by adjusting positions 60, 61, 62, 63, 64 and 65 on page 00 to read 80. Store each
location by pressing the stand-by button on the remote control.
6. Adjust the G2 and grey scale as below.
When adjusting the grey scale the following boxes will appear on the screen.
(RED) (GREEN) (BLUE)
(GAIN) ** ** **
(CUT OFF) e.g. 70 **
**
i. Using cross hatch pattern set the G2 so that the display in the Red cut off box reads between 60 and 80 as above.
NB. When adjusting the grey scale, the figures displayed in the boxes are an indication of the CRT’s performance
only. The data to be adjusted is contained in the box at the bottom right corner of the picture.
ii. Select a grey scale signal, then set the Red Cut-off level to 32 and the Red-Gain to 50.
iii.Leave the Red Cut-off and Gain as above and adjust Green and Blue Cut-off and Gain to achieve correct grey scale
tracking. As with all grey scale adjustments it will be necessary to readjust the settings to achieve good tracking.
Changing NVM Data
To change the data contained within the Non Volatile Memory, it is necessary to first select the page the data is stored in,
then the position and finally to change the data itself. The procedure below outlines this process.
then the position and finally to change the data itself. The procedure below outlines this process.
1. While on ALTER NVM PAGE, use the volume up/down buttons to change this data (data is shown in hexadecimal
format).
2. Press the channel up button and ALTER NVM POSITION appears, use the volume up/down buttons to change this data
(data is shown in hexadecimal format).
3. Press the channel up button and ALTER NVM VALUE appears, use the volume up/down buttons to change this data
(data is shown in hexadecimal format).
4. Once this data has been set, press the standby button to store.
5. If another NVM value has to be changed, use the channel down button to select the page or position and repeat as
5. If another NVM value has to be changed, use the channel down button to select the page or position and repeat as
necessary.
Note:
DO NOT change any NVM data, unless you have been advised to do so by a Sharp representative. If data is incorrectly
changed, serious damage may occur to the receiver.
DO NOT change any NVM data, unless you have been advised to do so by a Sharp representative. If data is incorrectly
changed, serious damage may occur to the receiver.
Procedure to re-set the NVM:
Modify the NVM values as in the below table.
Modify the NVM values as in the below table.
All the above values are hexadecimal.
NVM Page
NVM Position
Default Value
New value
00
7E
A5
A6
0C
20
Different on every set
Default value + 1
0C
61
Different on every set
Default value + 1
0D
3C
Different on every set
Default value + 1
0D
A5
Different on every set
Default value + 1
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