MJL V4 Power tests no 5 V ?/

Megajolt Kit assembly Question and Answers. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_kit_assembly_guide">Kit assembly guide</a>

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dinoman
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Joined: Tue Oct 20, 2009 10:19 am

MJL V4 Power tests no 5 V ?/

Post by dinoman »

Hi I built this V4 about 2 years ago and all I can is assume that all was well and tested after I built it, so now I get it out to fit to a friends MGC and just to familerise myself connected to my PC but soon realised it was not connecting as Led did not come on onced powered I have a wall wart regulated 12v and I can get 12v other side of Molex connector, checked for 5v between R9 and D1 and at R9 and D1 and getting zero v ?? so what can have gone wrong, I have checked a resoldered all the joints, so any help appreciated, Regards DM

brentp
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Post by brentp »

Your wall adapter might be putting out too much voltage- sometimes the voltage regulation isn't as precise as they claim. Can you verify the voltage the adapter is putting out ? A good alternative is to test with a fresh 9V battery.
Brent Picasso
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dinoman
Posts: 8
Joined: Tue Oct 20, 2009 10:19 am

Post by dinoman »

brentp wrote:Your wall adapter might be putting out too much voltage- sometimes the voltage regulation isn't as precise as they claim. Can you verify the voltage the adapter is putting out ? A good alternative is to test with a fresh 9V battery.
Hi Brent Thanks, my adaptor ( It is a regulated one) is putting out 12.05v other side of molex, and yes I started with a good 9v battery same result, Regards DM

brentp
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Post by brentp »

So do you measure voltage on the input of the voltage regulator U3?

See: http://www.autosportlabs.net/asl_dist/m ... v4_sch.png

You can also test on either side of D1
Brent Picasso
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dinoman
Posts: 8
Joined: Tue Oct 20, 2009 10:19 am

Post by dinoman »

brentp wrote:So do you measure voltage on the input of the voltage regulator U3?

See: http://www.autosportlabs.net/asl_dist/m ... v4_sch.png

You can also test on either side of D1
Hi Brent Thanks, on the left side of D1 I get Zero v and on the right side I get 0.3v Regards DM

dinoman
Posts: 8
Joined: Tue Oct 20, 2009 10:19 am

Post by dinoman »

dinoman wrote:
brentp wrote:So do you measure voltage on the input of the voltage regulator U3?

See: http://www.autosportlabs.net/asl_dist/m ... v4_sch.png

You can also test on either side of D1
Hi Brent Thanks, on the left side of D1 I get Zero v and on the right side I get 0.3v Regards DM
Hi Brent sorted, I redone the joints on U3 and all is well Led came straight on, so again Thanks, Regards DM

brentp
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Post by brentp »

Good news! thanks for being persistent :)
Brent Picasso
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