Agree, sorry for any confusion. Would the fact that something on the 15 volt power source drawing excessive current cause the snubber resistor to run hot enough to burn the solder joint, or is it more likely that the amp is drawing excessive current because the transformer or FET is damaged?
No, best I can tell is it is a 47.0 nF 250 volt cap that test 46.6 nF with my tester and does not read as shorted.
If I get time, I'll see if I can get that rev1 to power up to look at the waveform on the transistor.
Sounds good, I'd appreciate that. The pin of the transformer that is tied to the FET appears to have also gotten a bit warm at some point. The amps +\-15 volts measures -16 and only positive 13. Is it possible to jump pins on the 10 pin header to trick the amp into powering up without the preamp board?
I guess it would depend in how much of the amp you want to function. You may be able to apply 12v to the input of the 5v reg to get the low voltage section to function but I've never tried that.
If you're going to work on JL amps, you need to make a set of jumpers to link the preamp and main boards. They save a lot of time.
If you're going to work on JL amps, you need to make a set of jumpers to link the preamp and main boards. They save a lot of time.
Agree, I'll get the materials for jumper cables as I have a feeling they will be needed in trying to sort this amp out. With the driver cards removed the amp draw is less but still too high, the +\-15 is at -15 and +13.3. I'll let you know once I have the jumpers and resume troubleshooting this amp. Thanks again for the help.
The power light working intermittently was traced down to a solder joint that had failed, seemed like many of them near the power connector were in need of fresh solder. Probed around on the opamps and the signal in and out of them look pretty noisy.
I thought I remembered seeing a place in the tutorial about building some preamp board jumpers, do you happen to know off hand what section it is in?
I thought I remembered seeing a place in the tutorial about building some preamp board jumpers, do you happen to know off hand what section it is in?
As always thanks for the info, should have materials here to build a few jumpers by early next week. Have you had any luck getting your 500/5 powered up?
No. It may be a few days. In my spare time. I'm trying to get a downed tree cleared so I can cut grass.
I checked voltages in my rev 1 amp
-15.2v
+13.9v
-48v
+45.8v
q810 and q910 runs hot
my amp i half working
-15.2v
+13.9v
-48v
+45.8v
q810 and q910 runs hot
my amp i half working
Thanks, Jakobsson. Do you happen to have a scope to see what the wave looks like on pin 1 of the small yellow transformer? Also, what voltages do you have on the 10 pin header from the main board to the preamp board?
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