EDOT Lamp sequencer board or repair service for the board

Jason_971

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EDOT Lamp sequencer board or repair service for the board

It's probably a long shot, but just as the title says, I'm looking for a lamp sequencer board for an EDOT. I don't want to start messing with mine if it can't be replaced. I would prefer it to be working but will buy one untested or not working if necessary. None of the lights are working on my EDOT and I'm assuming that the lamp sequencer is to blame. PM me with any offers.

Thanks
Jason
 
i've worked on these, they used under powered transistors to start with.. you can shotgun replace them all with higher current rated devices. I have seen several where every transistor is toast, so it wouldn't surprise me if yours is the same.

if you're not in a hurry i could maybe look at this for you.
 
As Andy said, you need to replace all the MPS2222A transistors before you do anything else. They are way under powered for the job. I replaced all mine with new 2222's and some of them died within a year. Now I've replaced them all with TIP122's. You need to do a leg cross trick because the Emitter/Collector/Base pins are different between the two transistors. Since I've done it mine has been rock solid. Finding someone with a spare will not be easy or cheap I'm afraid, much easier to repair the one you have.
 
As Andy said, you need to replace all the MPS2222A transistors before you do anything else. They are way under powered for the job. I replaced all mine with new 2222's and some of them died within a year. Now I've replaced them all with TIP122's. You need to do a leg cross trick because the Emitter/Collector/Base pins are different between the two transistors. Since I've done it mine has been rock solid. Finding someone with a spare will not be easy or cheap I'm afraid, much easier to repair the one you have.

What's a leg cross trick?
 
The Cross Leg trick, I'll try and explain it;

For example you might have a transistor that instead of the pins E C B lining up (Pin 1 = E, Pin 2 = C, Pin 3 = B) with the PCB you might have pins in the order C E B (Pin 1 = C, Pin 2 = E, Pin 3 = B) so in order to fit it on a PCB you have to bend the pins so that say Pin 1 (C) would need to go into the pin 2 location on the PCB and Pin 2 (E) would need to go into the pin 1 location. To do this you bend the pins and they appear to cross over each other. This is fine but and works but it's VERY important to make sure the pins are bent enough so that they don't touch each other. With bigger transistors like the TIP122 this is fairly easy. I'll try a noddy ascii pic;

TIP122
| | |
EC B
X |
| | |
CE B (on PCB)
 
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The Cross Leg trick, I'll try and explain it;

For example you might have a transistor that instead of the pins E C B lining up (Pin 1 = E, Pin 2 = C, Pin 3 = B) with the PCB you might have pins in the order C E B (Pin 1 = C, Pin 2 = E, Pin 3 = B) so in order to fit it on a PCB you have to bend the pins so that say Pin 1 (C) would need to go into the pin 2 location on the PCB and Pin 2 (E) would need to go into the pin 1 location. To do this you bend the pins and they appear to cross over each other. This is fine but and works but it's VERY important to make sure the pins are bent enough so that they don't touch each other. With bigger transistors like the TIP122 this is fairly easy. I'll try a noddy ascii pic;

TIP122
| | |
EC B
X |
| | |
CE B (on PCB)

Thanks, I see, the pinouts are different. I'll probably grab some perf board and run wires to the board since everything would be so crammed together in there.

Thanks for the info.

Jason
 
cdjump probably repairs these. you might ping him.
 
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