I have 2 JL 1000/1 amps that someone previously attempted to determine what is wrong with them. (They did not know the first thing about Amp repairs and made a mess of them). Both have the same problem. I pulled all outputs and power fets and confirmed they were good. Tested for correct operation for power fets and reinstalled them. Powered up the Amp with no outputs found 95 volts on the gates of Q502, 503, 504, 505. Pulled and checked driver boards and can find nothing wrong. The issue is, with outputs installed, have low ohm light, and output transformer wine. (Checked all solder joints). Also have excessive current draw. Not sure where it would top out as I shut it off at 10 amps of draw. Current draw doesn't begin until a few seconds after start up.
The current draw doesn't start until the rail supply starts.
These amps don't like current limiting so if you only give it 10 amps of supply, it's likely to go into protect.
Do you have a scope?
These amps don't like current limiting so if you only give it 10 amps of supply, it's likely to go into protect.
Do you have a scope?
I believe I was misleading. My power supply provides 80 amps. I was simply monitoring the current draw and when it climbed to 10+ amps, shut it off to prevent any further damage. I do have a scope, but have limited experience with it.
I'm not sure what the 1000 will draw at startup but the 500 will draw 20-25 amps. After about 1 second, the currsnt drops to around 1-2 amps.
I'd suggest clamping all FETs to the heatsink, inserting something like an ATC15 fuse and give it at least 2-3 seconds to power up (after the short turn-on delay) with no other limiting but the fuse.
I'd suggest clamping all FETs to the heatsink, inserting something like an ATC15 fuse and give it at least 2-3 seconds to power up (after the short turn-on delay) with no other limiting but the fuse.
Okay. I will give that a try. I had all the fets clamped, none were getting hot. My concern is the whine I get from what I believe is the transformer at start up which is why I was limiting the draw at. All electrolytic capacitors are clean with no signs of leakage. I am wondering if the amps were wired on to low of ohms. Also have the low ohm light in conjunction with the transformer whine.
As stated the slash amps draw a large current spike at main supply wake up, my 5A limited bench supply will max out but manage to boot up a 500/1 but not a 1000/1. You need at least 15 amps for that one, and yes is makes what sounds like a hiss or a chirp from the transformer as it starts up.