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| "HELP"' |
| P259 fried due to output shorted to +12V U20 chip |
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I need someone in the states for a repair on my genboard. I burned one of the surface mount chips and I need a new chip and help replacing it.
* which chip exactly ? relatively easy to replace (except atmega) |
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* take note of the old chip direction. (perhaps note+photo)
* Cut legs * remove old chip and legs * no need to tin all pads * set new chip. Solder 1..2 legs first * verify position. Solder rest, one-at-a-time. |
| **It is the U20 chip. Can someone give 'detailed' instruction on the replacement. I know I have to clip the legs on the old one and desolder with iron and rope one at a time. For replacement, should I tin all pads before setting chip or set chip and solder one-at-a-time. |
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story of the blow-up:
The chip was damaged during cranking up after a long time with a broken engine. When I turned the key on the FP relay was cycling very quickly....maybe at 30hz or more. I thought the relay was bad, so I jumped the contacts to power the pump. This circuit also powers the injectors and some sensors on the engine(I reused the old edlebrock pro-flo harness and it was wired this way). I did this and had my brother turn on the key to start the engine. About 5 seconds after I jumpered and 2 seconds after he turned the key on, I heard a pop in the Genboard. Removal showed a nut fell from the IGB heat sink and was loose. It also showed the U20 has a small(maybe 1.5mm) chip blown from the top and smells like a plastic fire. My assumtion is that the nut caused a shorting of the chip. I dont think shorting the relay caused the chip failure from what I can tell of the genboard schematic...but I could be wrong. |
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* any more details about how it got damaged ? Just to get an idea about the possibility of other damage
**The chip was damaged during cranking up after a long time with a broken engine. When I turned the key on the FP relay was cycling very quickly....maybe at 30hz or more. I thought the relay was bad, so I jumped the contacts to power the pump. This circuit also powers the injectors and some sensors on the engine(I reused the old edlebrock pro-flo harness and it was wired this way). I did this and had my brother turn on the key to start the engine. About 5 seconds after I jumpered and 2 seconds after he turned the key on, I heard a pop in the Genboard. Removal showed a nut fell from the IGB heat sink and was loose. It also showed the U20 has a small(maybe 1.5mm) chip blown from the top and smells like a plastic fire. My assumtion is that the nut caused a shorting of the chip. I dont think shorting the relay caused the chip failure from what I can tell of the genboard schematic...but I could be wrong. * write the shipping address (where you expect the chip) to a shop note (or you can fire an order, checkout with IBAN, we can send you the chip for free) I will send a note. ------------ |
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