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dead ecu?

I got an old ecu off a mate, it had blown the big cap, so i repaired the trace damages and chucked in new caps.
Also one of the small black IC's was damaged so I replaced that also.

PROBLEM: the ecu will still not start the car.

I took another look at it, and it looks like the CPU has a 'rise' in the center. Upon comparing to all my others, they dont have this.
My question - how common is it for the caps to blow and fry the cpu? Has anyone seen this before?


Terry Posten

Well-known member
Dec 16, 2003
Davenport, Iowa USA
Yes it is. You sent 12volts into a 5volt part.

Unless you have access to top mount soldering equipment, a donor chip, and are VERY good, it's junk.


i have some top mount soldering gear, and a spare chip from a non turbo car...will this work?
Once you change the pin config of the chip it changes to an external rom - am i right?


Well-known member
Oct 23, 2004
St. Charles, IL USA
Unless this is a EPROM ECU you need a CPU chip with the same E code as the original. That's the version of the software that was mask programmed when the silicon was doped.

If it's a EPROM board then it's already providing the pin levels at reset to configure the CPU for expanded mode and the internal software version shouldn't really matter.

perfect, the dead board is an eprom board, and i have a part ecu which was a non eprom - i will solder on the new cpu and see what happens!
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