JBL GTO 14001

[mike49504]

Theres a part in this that appears to be a thermal switch

The board location is SW1 The part number on it is JUC-21F and says 80 degress C


Wondering if anyone know where i can get one of theese or a good replacement part?

[Perry Babin]

Is the one in the amp missing?

[mike49504]

The one in the amp is defective the back plate is missing

[Perry Babin]

The original part should be available from JBL. If it's not, post a photo of it.

[mike49504]

Ok got the new part from JBL and put it in..

It appears that the driverboard for the power supply has been messed with ..


Amp will not power up at all no lights no nothing


I get 0 volts on all pins of the 595 besides the ones that have the battery voltage Like Pin 8 I think Pin 11 and 1 other one..

Any ideas on what to look for?

[Perry Babin]

You'll need to post the voltage on all pins of the 494.

Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:

[mike49504]

Ok found 1 problem there is a broken solder connection on 1 of the pins for the driverboard and will have to pull it and look..

Once i wiggle the board around i get the amps light to come on but it draws excessive current..

[Perry Babin]

If someone pulled the driver board before and the main board is double-sided, there may be multiple damaged vias. If you pull the driver board, photograph the traces under it (unless you can remember them) so you can confirm that all of the top traces have continuity with the pins on the board.

[mike49504]

Yes the Vias is damaged on atleast 4 of them..

Whats the best way to try and repair them?

[Perry Babin]

There's no single best way to reestablish the connections. I like drilling and using a jumper wire looped around the leg of the connector but that requires a small drill bit (#66-#60) and a bit of thought to make sure that you don't drill through other traces. You end up with something like the jumpers in the attached images.