Quoted from madmatt1:It blows about 5 to 8 second after I turn on the pin.
If I had to guess the same amount of time everytime.
Thanks,
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OUT
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Ha, I kept it short! LOL.
With a messed up BR1, it would blow as soon as you hit the 'on' switch even if it is a slow blow, so if it's taking 5-8 seconds...then something else is likely going on. If you replace F1, and turn it on, does it get hot (i.e. glows red) right away? Not sure how long a sloblo fuse takes to pop, but I would think it is less than 5-8 sec. Of course, it depends on how much current the problem is drawing.
And I would think the power supply comes up long before that. But I'm just 'thinking out loud' and don't really know the time constants. So to me, it sounds like the power supply might be OK, but when something somewhere else turns on (and the fuse blows)...there's the problem. I admit I not an expert w/the circuit, I'm just a EE and looking at the schematic. Far more people with knowledge about the power supply than me, just my 2 cents and don't want to steer you wrong.
I'd take a closer look at that CN7 path, and try to figure out what's on it. Again...just guessing
Testing R5, R6...the connections look pretty good. Just find a magnifier and take a close look at the solder connections (or just resolder). That holds true for all the connections You can check a diode w/the DMM...just look for the diode symbol on the dial. But testing in the circuit is iffy since it's still in the circuit and everything connected to it can result in false readings. Put the leads on way it should read open, switch them and it should read ~0.7. More often than not, the reading will be bougus unless you remove and test. I'd still test them in the circuit away (with the power off).
My comment about D2 - that was in error (I looked at the circuit wrong) - but diodes are prone to failure, so not a bad idea to test anyway. D2 doesn't look bad, the lead just looks a corroded for some reason.
Hope I'm not steering you wrong on any of my comments! Just for the heck of it, here's a link to the regulator: https://www.futurlec.com/Motorola/MC1723CP.shtml
Good luck!