Cynic-al Posted May 16, 2012 Author Share Posted May 16, 2012 Well i'm pretty sure the faults are D10, D12, the link between D10 and D12 is broken as is the link between D12 and C16. I've ordered the components so will replace / repair and see how we go from there. I'm thinking of upgrading my multimeter to one that also does capacitance, seem to be a good selection in the £15 - £50 range, any recommendations? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 16, 2012 Share Posted May 16, 2012 Unless D10 was open-circuit it shouldn't matter if it goes short-circuit as it's a reverse-polarity protection diode. If it's exploding, that means something on the "C" side is drawing too much power. Suspects #1 and #2 are D12 (over-voltage protection zener) and C16, especially if C16 has been fitted back-to-front as is quite easy not impossible to do. To prove things, if you have a KNOWN GOOD 12v (or even 9v battery) power supply, you can just remove D12 and short across D10. The only other thing running on the S12C side is the 5v regulator. Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted May 16, 2012 Author Share Posted May 16, 2012 D10 and D12 are certainly broken as i've pulled them and tested them, they both conduct both ways at 9v. Thats also how i'm sure the tracks mentioned above are broken, no conductivity where the components used to be. I'll just link it with a bit of wire when i replace the damaged components. I suspect C16 is the right way round as its an old board and has been in use a long time by various people. I will see if I can get C16 to take charge off the multimeter to prove there is some life in it, however that is the reason for looking to upgrade the multimeter. What does S12 and S12C Jmp refer to? Cheers for the feedback Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted May 18, 2012 Author Share Posted May 18, 2012 Well i think i've fixed it. D10 & D12 replaced and 2 tracks cut out and replaced with cable. It's now talking to the pc and priming the fuel pump when i power it on. It also seems to still have all the settings which is a good sign too. Not tried it on the car yet but fingers crossed it's fixed and has a few more years service in it. Cheers all. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted May 18, 2012 Share Posted May 18, 2012 Might be an idea to check out the car to see if you can see why it failed..... it may just be that d12 failed from age and took d10 out and a few tracks with it .... or maybe there's a wiring or overvoltage problem. Just a thought..... Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted May 19, 2012 Author Share Posted May 19, 2012 Probably a good idea Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted May 23, 2012 Author Share Posted May 23, 2012 Partial victory. I checked over the car wiring, all seemed fine. Car started ... but ran rough. Got the laptop out and MAP is sat at 100. I've put a bit of pipe on and sucked and blowed with no change to the reading. Back to the man shed! A bit of tracing the wiring diagrams and I found the pins on the sensor weren't conducting properly. A run of solder along each leg seems to have fixed it. I must have caused damage when I bent the sensor out of the way to repair one of the broken cables. Back to the car! Fingers crossed Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 23, 2012 Share Posted May 23, 2012 Bending the sensor is a risky operation, they are sensitive to mechanical deformation, and you can lift PCB tracks off the board doing that. Just for info! Glad you got it fixed though. Are you going to glue those wires down? Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted May 24, 2012 Author Share Posted May 24, 2012 Yeah bending the sensor wasn't nice but i didn't fancy trying to desolder Plugged it in this morning and teh engine started at ran so at the moment i'm happy, lets hope it stays that way I was going to leave the wires as they are, it'll keep me entertained in a years time Quote Link to comment Share on other sites More sharing options...
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