D3adlyX

Anybody know how long an amp can stay in protection mode?
Like is the current still running trough the amp when its in protection or how does it work?
Just wanna know if its safe for me to turn an amp on that will go straight into protection and leave it there so i can test a few things with my multi meter...

Thanks

Tubeamp

To answer your question, it depends the amplifier and what is sending it into protection. A common way to test "live" is to use a variac and slowly bring a low voltage and low current into the amp for testing. At the very least, keep the source current to a very minimum (mA) as you may run the risk of causing more problems then what you started with.

If you're not sure, passively test the components in/out of circuit and replace what is bad, then turn on... slowly.

Hope this helps!

kevmurray

No worries you're fine. When the protection circuit kicks in the amps power supply stops switching and powers down the amp modules. If you can power it up without blowing a fuse then I would just change the output transistors. What amp is this?

D3adlyX

its that kicker zx650.4...
i replaced all power supply and half of the output.... because there were 4 types
tip35, tip36, tip45 and tip46..
1 tip35 and 1 tip36 were dead...
so i replaced all 4..

didnt bother with the other ones considering i tested them out of the board and they were fine...
the amp still seems to be going into protection though and i checked the resistors near the mosfets and they read fine as well...

kevmurray

Did you remove the output fets to test them?

D3adlyX

yea... i removed all the fets and tested them all individually...
i replaced all 10 power supply fets...
and replaced all tip35 and tip36..
the tip 45 and tip46 all read ok and werent dead so i never replaced those.

Tubeamp

You may also have a bad zener, or some form of other voltage regulation issue?

Hope this helps!

D3adlyX

Yea... i'm going to go test some more...
this is what i noticed when i looked at the back of the board...
Let me know what you think.... there is some blackened on the board's speaker outputs...

Mach5

what is protecting it?

D3adlyX

if i knew i woulda had this fixed by now....