Color Cells CC784 Repair & Restoration Log

[ReeceyBurger123]

Recently im looking into building my own Led sign board. Wanted to get familiar with them before launching into a project, so picked this up off ebay for £20 delivered ! The guy selling it was down the road from me This unit is the Colour Cells CC784 Programmable Led Signboard, a very interesting one to. Its based off a shift register design with MC1413P Ics to select the Leds made in about 1989 so quite old. Comes with a remote which has letters on that you can type and programme for the display.

This unit however needs some minor repair, the unit when powered off the memory seems to corrupt and forgets what has been written to the display and acts like its from factory. I have not yet opened it to diagnose but will have a look soon looks like it has a memory battery so probably just needs changing. I will also be restoring and replacing every Led in it with brand new ones to help the reliably of the unit.

TBC

[stj]

fixed those!

get that bitch open fast and bin the nicad battery.

[ReeceyBurger123]

Deffo mate just waiting on someone to pick a Tv up What failure did yours have ?

[ReeceyBurger123]

Lol have a look at this bodge repair job didnt even bother to replace the corroded diode and resistor

[Spork Schivago]

Originally Posted by ReeceyBurger123

Recently im looking into building my own Led sign board. Wanted to get familiar with them before launching into a project, so picked this up off ebay for £20 delivered ! The guy selling it was down the road from me This unit is the Colour Cells CC784 Programmable Led Signboard, a very interesting one to. Its based off a shift register design with MC1413P Ics to select the Leds made in about 1989 so quite old. Comes with a remote which has letters on that you can type and programme for the display.

This unit however needs some minor repair, the unit when powered off the memory seems to corrupt and forgets what has been written to the display and acts like its from factory. I have not yet opened it to diagnose but will have a look soon looks like it has a memory battery so probably just needs changing. I will also be restoring and replacing every Led in it with brand new ones to help the reliably of the unit.

TBC

Wow, that's cool. We have this signs by the road that are portable. The city puts them up to give us messages, like Road Closed December 12th - 24th for repairs. Or Watch out for pedestrians! I've always wanted to learn how they put the messages on them and sneak down at night one night and add 2600 or something to the one of the messages. A lot of times they'll have a few screens worth of messages. Like display one message for so many seconds, then display another. I wouldn't erase the original messages, just add a new one that says 2600. I thought that'd be great.

[Spork Schivago]

Originally Posted by ReeceyBurger123

Lol have a look at this bodge repair job didnt even bother to replace the corroded diode and resistor

Wow, look at all those ICs. That thing is cool as hell man. Wish I could find one for 20$.

[ReeceyBurger123]

Originally Posted by Spork Schivago

Wow, that's cool. We have this signs by the road that are portable. The city puts them up to give us messages, like Road Closed December 12th - 24th for repairs. Or Watch out for pedestrians! I've always wanted to learn how they put the messages on them and sneak down at night one night and add 2600 or something to the one of the messages. A lot of times they'll have a few screens worth of messages. Like display one message for so many seconds, then display another. I wouldn't erase the original messages, just add a new one that says 2600. I thought that'd be great.

Yeah man Interesting stuff this is, very well designed for a device this old. Newer types if Led sign boards use Led controllers which are less complex but work just as well and can control alot more Leds.

[ReeceyBurger123]

Originally Posted by Spork Schivago

Wow, look at all those ICs. That thing is cool as hell man. Wish I could find one for 20$.

Yep the Ic's are the supporting Epproms for the shift Ics then there is a further stage of decoupling for them. Getting a parts list together to restore this thing The guy attempted a repair but didnt fix the failed parts so im going to now, needs a 3.7v 300mha battery for it better get looking

[ReeceyBurger123]

Originally Posted by stj

fixed those!

get that bitch open fast and bin the nicad battery.

What battery is used buddy you got a part number ? So far I know its a 3.7v 300mha but not too sure.

[stj]

3cell pile of shit - dont worry about it.

you need to clean the corrosion by throwing vinegar all over it,
then remove the charge resistor in parallel with the diode from the battery and fit a cr2032 coincell holder.
lithium coincells are more reliable.

oh - i dont think i need to say what i needed to fix in them!

if they are real bad, you have to lift and replace chipsockets!

[stj]

btw, once it works you'l love the animated shit like the steam engine!!

[ReeceyBurger123]

Nice one, so remove the resistor and diode, then install a cr2032 socket and battery guessing that the diode and resistor that charge the previous battery? Also removed them chips before and the sockets are corroded so got to clean them as well as the pins on the Ic's.

[ReeceyBurger123]

Just to be sure, is this the diode and resistor you mean ?

[stj]

the diode and resistor are inline with the battery,
the diode stops the battery getting hit with 5v when it's running,
the resistor bleeds some power across the diode to charge the battery.

you must have the diode inline with the battery to prevent it getting destroyed by 5v,
but you remove the resistor to prevent it being recharged.

diode should be a schottky to minimise the voltdrop btw, the battery will be 3v and the ram is rated down to 2v from what i remember.

[stj]

lol your foto shows they put the diode and resistor in each others places!

they should lead to the battery + terminal

[ReeceyBurger123]

I see the ones you mean now, the resistor is at the top here and the diode is at the bottom. So remove the resistor when adding the CR2032 socket ?

[ReeceyBurger123]

Originally Posted by stj

lol your foto shows they put the diode and resistor in each others places!

they should lead to the battery + terminal

Doh ! Hey im tired haha

[Robo129]

I am no rocket scientist or hardly know anything about electronics but am attempting this fix. Do you mean remove both resister and diode. How many CR 2032 batteries will I need to replace the others. Can you please post exactly step by step as to what I have to do. Appreciate immensely. Bob

[stj]

just remove the resistor,
and use a single cr2032 battery.

[Sheeshbajeesh]

I'm working on removing the NICAD from mine as well and doing this battery mod. The resister to be removed is R4 on the main board, correct?