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jt_sg
Siedler
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Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 06:55
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Hello, I am from Singapore and obtained a LLE flipdot 16x64 from a scrapped bus. The flipdot used to work, but when i turned it on after 1 year of storage, it does not work anymore. It seems to be a problem that many other collectors in Singapore face. Does any one know how to fix this control board? There are 2 flip dot modules, but when connected only one module can scroll. No response when pressing the controller as well.
Geändert von jt_sg am 12.Jun.2017 7:12
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MagnusMagus
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673 Beiträge
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RE: Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 10:00
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Hi,
acid damage due to failed Ni-Ca Battery(the big VARTA one).
You can repair the board if you have good soldering skills.
Unfortunately for you the board was setup for data storage in RAM, as the Battery failed the RAM chip also lost all of the data(configuration and sign texts)
So to fix you would need
1) Fix the board
a) Get a new battery or a 120kOhm resistor(as you will never be using RAM storage again)
b) Remove the battery, clean the residue with Isopropanol or 99% alcohol. (any other PCB cleaning solution will work as well as long as it‘s quick to dry)
c) Use a multimeter to check data lines between the CPU and the FW socket, trace them and connect the failed ones
d) Install the resistor or battery
2) Convert to EPROM storage
a) Get yourself a W27C512 chip and a EPROM programmer(or ask local repair shops, usually the ones doing security systems/engine controller repairs have them )
b) Get TedPlus or ask somebody in this forum help you with the DATA
c) Burn data to chip and install
You could ship the board in for repair, but I think the local repair shops can do the repair faster and way cheaper, the board is very simple and easy to repair by a trained technician.
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jt_sg
Siedler
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RE: Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 12:46
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I see, however, this same problems is also caused when the sign itself has been impacted, mostly due to dropping during removal. Could the impact have damaged the battery as well?
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MagnusMagus
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RE: Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 13:15
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Could the impact have damaged the battery as well?
Only if the battery was about to leak. The batteries are rated for 10y max, so it was about time for it to go.
Also if you do not remove it in time it will get worse, like this
https://goo.gl/photos/y5M2X3nCaHVWsvtv6
(this board was repaired)
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jt_sg
Siedler
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RE: Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 17:38
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*Deleted*
Geändert von jt_sg am 12.Jun.2017 18:10
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 18:09
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My knowledge regarding electronics is quite limited, so would you be able to point out which is the RAM chip?
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MagnusMagus
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RE: Help Needed: 1994 Lawo Luminator Europa , 12 Jun. 2017 18:11
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99% that it did not survive, as when the battery starts leaking it can no longer support 3V. Also if you ever removed the chip from the socket - the data would be whipped immediately.
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 05:16
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Ok thanks, is the RAM chip the one next to the battery? Or the one above it
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MagnusMagus
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 07:49
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RAM Chip that contains the Sign Data is the one in the green socket with the lever on the right side of the board.
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 09:56
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Thanks. Looks like I‘m going to have to spend quite a decent amount of time just to reprogram all the data for the sign
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 10:02
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[QUOTE]
a) Get a new battery or a 120kOhm resistor
May I ask, what is the purpose of the resistor? Could I just use a short piece of wire instead?
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MagnusMagus
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 10:21
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The battery control chip expects a very small current on the battery, smth around 4uA to determine that the Battery is charged and working. Anything between 80kOhm and 120kOhm should work. If you short circuit - the battery control chip may break. Additionally if the chip(8 Pin small one near the battery) is made by MAXim, the board should start without the Battery. Just to test if the board starts you can also push and hold the green button, the 7 segment display should go through various numbers and stop at 0, then 5 if no control unit is connected.
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 10:53
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Tried that, the LED segment only shows F when then RAM chip is connected, but once I take out the RAM chip it just stays at C
Edit: it can go to 5
Geändert von jt_sg am 13.Jun.2017 10:53
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MagnusMagus
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 11:08
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that‘s because there is no data in the RAM chip, and the board can not read the sign configuration.
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 15:28
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I see. Thanks for your help.
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jt_sg
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 17:56
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By the way, would there be any other EPROMs that you‘d recommend? I‘d prefer one that is not OTP.
*EDIT* I saw a photo of the W27C512-45 and assumed that it was a OTP. After checking the data sheet for it then I realized it was a EEPROM
Geändert von jt_sg am 13.Jun.2017 18:50
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MagnusMagus
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RE: Help Needed: 1994 Lawo Luminator Europa , 13 Jun. 2017 18:07
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W27C512 - the only one one that works 100% of the time and can be erased programmatically. Price +-80 cent on aliexpress/ebay.
If you have a UV eraser then any 27C256 will do, the one from ST are most common in Europe, but AMD, INTEL and others work. Usually cost +-1-2 EUR in Europe.
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