Failed backlight on Byvac BV4613 LCD

Hi all
ive had a project running for several years, its an 8 channel reptile Temperature controller, its all been working fine but now the LCD backlight has failed. Heres what i believe is the type:

Its running in serial mode, only one or two wires for the serial data and the little back-board (BV4613) on the back of the LCD does the data conversion. I think its a 192 x 64 lcd, and Its configured for 8 lines x 32 characters. Display area is approx 85mm x 31mm.

I can't get these LCD's anymore, (Ive looked everywhere , definitely cant get a compatible backlight replacement part either). I was wondering if anyone knows if there is a direct replacement LCD that would work using the current code? Its using the BSerial and BVSerial libraries (lcd.put etc).

Any pointers (sorry about the pun) most appreciated.

Cheers
David

Hi David,

I used to know Jim, who created ByVac, but lost contact with him during covid lockdowns. He has retired from running ByVac, so I'm not sure about your chances of getting a replacement that way. But only the "backpack" was Jim's design, the LCD display itself is a standard part: as KS0108 graphic LCD.

You can still get these on eBay etc:

128x64
https://www.ebay.co.uk/itm/252501258727

192x64
https://www.ebay.co.uk/itm/324250503502

What you will need to do is carefully unsolder the ByVac backpack from the failed display and solder it to a new one. Unsoldering a 20-way PCB header pin can be tricky if you are not experienced at soldering (or rather, desoldering) and care must be taken not to rip the pads off the ByVac backpack. It may be safer to remove the LCD, leaving the PCB pins in the ByVac backpack.

Paul, thank you so much, thats really good info, and I can sort all that out – no probs with the soldering!

One question: The example you sent says 128x64 but the ByVac site says the BV4613 is a 192x64 graphics LCD controller

Just wanted to confirm which one I should be going for ?

Cheers

David

I suspect it can control either 128x64 or 192x64 LCDs, so long as they have KS0108 controller.

If you have 192x64 then you really should replace like-with-like. You won't get 32x8 characters on 128x64, probably only 20x8. Unfortunately, 192x64 is more difficult to find and therefore more costly.

I posted links to both sizes above.

On great thanks Paul

I have another reptile controller that I built more recently and it uses the ST7920 lcd so maybe it will be easier and cheaper to upgrade the lcd to that. Will involve code changes but it won’t be too onerous. Thanks for all your excellent help.

Regards
David

Regards

David Every

Software, IT, and Music Electronics Tech

Hi Paul

A weird one

The backlight was definitely “OFF” for a few days, even though the unit was doing its job. But I happened to unplug the USB cable between the PC and the Arduino, then turned the reptile controller off and on again (it has an internal power supply) and bingo, up came the backlight.

Seems to be some issue with conflict between the internal power supply and the supply coming from the USB cable/socket – strange but its looking like I don’t have to fix anything….

Regards

David

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