MJL V4 Power tests no 5 V ?/
Moderators: JeffC, rdoherty, stieg, brentp
MJL V4 Power tests no 5 V ?/
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
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 DMbrentp 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, on the left side of D1 I get Zero v and on the right side I get 0.3v Regards DMbrentp 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 sorted, I redone the joints on U3 and all is well Led came straight on, so again Thanks, Regards DMdinoman wrote:Hi Brent Thanks, on the left side of D1 I get Zero v and on the right side I get 0.3v Regards DMbrentp 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