Looking inside FZR 250 Cdi unit

Hi, when we got the bike, the owner had the old faulty unit, so I opened it up to have a look inside. I understand that not only is it a Cdi unit, but also controls the exup and other ignition type functions?

I did not have a small hobby saw, so I used a heat gun (read soldering iron.... Oops!) to cut the plastic case, as you can't pull the pcb out as it is glued in with contact type glue. Photos follow:



Now opening her up.....







And here's the other side of the pcb........




Ther's a lot more to it than I thought there would be..... ( Eg. the large IC etc) Any comments?

 

they're not that complicated - basically the larger transistors will often crack if they fail, the only components which wear out in those units are the electrolytic capacitors because the electrolyte in them slowly escapes due to normal usage.

the large IC is just a processor with an EEPROM but PDF's for the specs are almost impossible to obtain

When I had mine apart and replaced all of the caps I noticed there wasn't a lot else to go wrong and most potential failure parts are obtainable

 

for what it's worth it's simple enough to replace most of the potential culprits in one hit - it's a really bad diagnosis strategy, but transistors, resistors and diodes are simple enough to test, or just replace them.

When I searched years ago for the main IC datasheet I was hoping to potentially suck the EEPROM data off and decode to potentially change it and reflash - AAH pipe dreams

 

I still have it somewhere I think.... I've seen replacement ones somewhere (non-Yamaha....).... I have done Eprom programming in the past... (a long time ago)...

 

Yeah it would have been great to be able to reprogam them or at least extract the ignition parameters to potentially repair them in the case of failure