I had a similair problem with an amp and the caps were leaking, and the fluid that leaked out made a dark spot on the board and it was causing traces to arc between each other, where the dark area was.
it really doesnt looks like it is leaking... i see nothing at all that would look like leaking and the caps all looks mint ... the spots i am talking about are underneath the PCB on the solder side... like when an electric spark occurs.. them look like the ones i make when discharging the caps with my headlight.. but way more dark
i will dissolder them to check it out...
I have a function on my DMM to test caps up to 2000uF and they are 1500uF so i guess i will be ok
I have a function on my DMM to test caps up to 2000uF and they are 1500uF so i guess i will be ok
do you think i could check the circuit without the caps on the board ?
just for testing purposes??
just for testing purposes??
That I cannot answer but I misunderstood you I guess. I thought the dark area was around the caps, sorry. Something either touched or became so hot it made a solder bridge and shorted, maybe taking a cap out??
i guess my headlight **** did not work to empty the caps.. i just got one nasty POW using the wick ...
the only thing that worked was the resistor but it still made a spark so i was trying to use something else... i guess the headlight is not good..
the only thing that worked was the resistor but it still made a spark so i was trying to use something else... i guess the headlight is not good..
I use a 25 watt 5 ohm resistor and it works great with minimal spark. Never tried a headlight before.
could the mic4420 you sent me be blown and make the output FETs fully powered ? pulling this huge ammount of power ...
where is Perry 🙁 right where I am in fire to search on this thing 🙁
I guess he as to sleep sometimes 😛
where is Perry 🙁 right where I am in fire to search on this thing 🙁
I guess he as to sleep sometimes 😛
I didn't receive any email telling me that there was a reply here.
What's the resistance from the gate to the source of the output FETs? What's the lowest reading you have?
What's the resistance from the gate to the source of the output FETs? What's the lowest reading you have?
Even if the MIC4420CT was blown I have never seen one cause these problems such as you are having, not saying it isnt possible but unlikely. It almost sounds like you have a shorted output(s). Run the test like Perry said alot of times by checking the resistance form gate to source you can tell if a fet is shorted. Especially if you have 1 with a really low number like 1.9, 2.4, etc etc.....
did you had time to check out the zillion posts i made Perry ? lol
maybe it could help you to surround the problem
i have dissoldered the 3 right caps and now i will check the resistance between gate and source on all the outputs
it wont be long
maybe it could help you to surround the problem
i have dissoldered the 3 right caps and now i will check the resistance between gate and source on all the outputs
it wont be long
finally its not a capacitor check that i have on my DMM its an AMP check that is in the range of 200u and 2000u...
how can i measure the caps out of the circuit ?
how can i measure the caps out of the circuit ?
they all read a charge/discharged when testing them with the DMM on 2K scale... none are short or leaking
i dont have anything higher than 2000K (2M) on that DMM
and the other DMM i have is a cheap one with 20M range (walmart crap) and even that one reads open...
and the other DMM i have is a cheap one with 20M range (walmart crap) and even that one reads open...
Maybe the rail caps being out are affecting your readings, if their fine you should re-install them and recheck the gate to source resistance on the output fets. I am sure Perry will chime in to steer you in the right direction soon, he is probably reading your zillion posts.....LOL
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