LCD

[2PAC Mafia]

Hi guys,

we have been working with a LCD adaptation to an electronic unit which has obsolete original component. We bought 2 units and made them working properly. When we wanted to make more of them we received a different type of unit of LCD and now the new ones are not working. In theory they are fully compatible. Do you have any idea?

The LCD´s are 160x128 8080 parallel port based on chip T6963.

 

[2PAC Mafia]

On the good ones the chip is RA6963 and on the not working ones we have the SAP1024B

 

[MichaelaJoy]

LCDs in general are tricky to work with, because they are timing sensitive.

Especially the SPI (serial) ones.

More than likely the new display has a different timing need, and needs to be adjusted for in software.

Carefully check the timing specs of both displays and compare them side by side.

 

[unclejed613]

it's difficult to tell from the pictures exactly what is causing your problem. one thing i can tell you is that the smearing effect on the non-working panel is not normal, even for a panel getting confused signals. it looks like the new panel is supposed to be a replacement for the old one, judging by the part number on the sticker. but even then, without more documentation than the connector pinout (a schematic would be ideal, but a data sheet with the signal, power, and data timing information (for both boards) would be a big help. the smearing problem appears to be something more wrong than just incompatibility of the interface, so it could be you have a defective panel.

 

[Ian Rogers]

I use a lot of different Toshiba modules.. I have used all three of those chipsets..

From what I see the -15v isn't strong enough I used a separate -15 v convertor ( Now almost extinct!!) the MAX xxx ( can't remember the exact model ) Give a good strong negative voltage.... Some of these units make their own... What size resistor do you have on the -ve to Vo?


Actually... The "Good one" Has the -Ve on board.... The non working doesn't seem to have one..

 

[unclejed613]

The non working doesn't seem to have one..

that could have something to do with that smearing on the non-working panel.

 

[2PAC Mafia]

Thank you guys. Finally we received a datasheet from China and we saw the non working displays needed negative voltage on Vcc (pin 4). It is needed to install a potentiometer between pin 4, 5 and GND.

On the good one, first on, on pin Vcc (pin 4) uses +5V. We have tested it and that was the difference!!!