JBL GTO 14001

[S Merlington]

I bought this amp off a friend ..

So far i replaced the power supply fets (IRF3205) Replaced the gate resistors (100 ohm)

Replaced the 47 ohm 5 watt resistors that sit next to the relays

Removed all output transistors since they were defective... Replaced the 2 IR2010 Driver IC's on the the Audio driverboards..


As soon as i apply power ground and remote the amp will draw 20 amps of current and theese resistors start smoking within 5 secs i can see smoke comming from them There is no outputs in the amp right now since im trying to figure out why theese resistors start smoking within 5 secs


Any ideas ??

 

[S Merlington]

Ok solved that problem..

Put the outputs in the amp and now when powering up L9 squeals loudly if i keep taking the remote wire off and applying it over and over again i can get L9 to stop squealing and the amp will produce clean audio..


See pic Any ideas??

 

[Hadighorbani]

hi
do you have shematic for amplifire section off JBL1400 ?
thanks

 

[Perry Babin]

It appears that the blue capacitors have vented. Have you confirmed that they are within tolerance?

 

[S Merlington]

I will replace them and see if i still get that squeal

 

[S Merlington]

Replaced the caps.. Amp powers up but the relays keep clicking on and off amp goes in and out of protection mode..

 

[S Merlington]

ok i found 2 bad resistors on the driverboard eplaced them put it back in the amp and now L9 just squeals like crazy and the 47 5w resistors start smoking when i try to power it up..

 

[S Merlington]

Ok i pulled both audio driverboards amp powers up and idles perfectly no squeal..


So im guessing something on the driverboard or boards is defective..

 

[Perry Babin]

Those resistors appear to act as a load for the output stage before the relays engage.

Did any of the heatsink mounted transistors heat up when L9 squealed?

Do you see any signs of overheating on L8 or L9?

Is it possible that the amp isn't powering up properly because the 12v power supply doesn't have enough current capacity?

When it did power up, did you see clean audio on the positive and the negative speaker terminals?

 

[S Merlington]

Those resistors appear to act as a load for the output stage before the relays engage.

Did any of the heatsink mounted transistors heat up when L9 squealed?

Do you see any signs of overheating on L8 or L9?

Is it possible that the amp isn't powering up properly because the 12v power supply doesn't have enough current capacity?

When it did power up, did you see clean audio on the positive and the negative speaker terminals?

No Heatsink components got hot..

The amp is powering up now without the driverboards in it Im putting sockets in for the driverboards so i dont have to keep unsoldering them dont wanna damage the board..


Ill try to get it powerd up again as soon as i get done soldering the sockets in place..

 

[S Merlington]

L8 and L9 have no signs of over-heating..

If i plug both driverboards in L9 starts squealing..

If i plug only 1 driverboard in doesnt matter which one the amp will power up and idle normal


If i plug the driverboard in this location L9 starts squealing it doesnt matter which driverboard i plug in this location L9 still squeals

 

[Perry Babin]

The reason that I asked about the current capacity of the supply is because it's unlikely that the amp would work perfectly after you apply remote repeatedly if there was a problem in the output stage of the amp.

 

[S Merlington]

The amp doesn't work now it just keeps squealing no matter what

 

[Perry Babin]

Even with both driver boards out?

 

[S Merlington]

If i remove both driverboards the amp powers up and idle's perfectly..

If i put 1 driverboard in the amp In this location yellow arrows pointing to it the amp will power up and idle perfectly.. it doesnt matter which driverboard..

If i try to put a driverboard doesnt matter which driverboard i use in this location Red arrows pointing to it L9 squelas like crazy..

So im guessing both driverboards are working correctly and the problem is on the main board..

 

[Perry Babin]

Can you remove L8/9 and reverse their positions to see if the problem follows the inductor that's currently in the L9 location?