hells gain marshall emulation trouble shooting

Started by Belanger, October 06, 2016, 12:37:28 PM

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Belanger

hey this layout was just added and is unverified, I built it up but my 1n5817,47ohm and 7660s are all over heating drastically and I cant find where the short is   its not between the tracks because ive re melted and cleaned between the tracks over and over. I've also tried changing the 7660s. when I took out the charge pump theres no more overheating of the other components

voltages are as follows (with out the charge pump)


tl072 all numbers are in order 1-8,14
8.43
4.06
0
0
1.1
1.5
9

tl074
0.7
.75
0
9
1.7
2.18
2.2
8.21
.75
1.3
.75
0
.7
.8

7660s socket
9
0
0
0
0
0
0
9

ill post more pics in a min
The best substitute for intelligence is silence

Belanger

The best substitute for intelligence is silence

Belanger

The best substitute for intelligence is silence

Belanger

The best substitute for intelligence is silence

bluebunny

Not sure, but I think that long link that takes the -9V to pin 11 of the TL074 has reached the wrong pin.  It should go into the (empty) hole immediately above the line of five cuts, and there should be ten spaces between it and the top of the link - you have nine.
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Belanger

The best substitute for intelligence is silence

Belanger

ok I replaced the 1N5817,47ohm resistor and moved the long link but the 1N5817 and the resistor are still really overheating within a few seconds of being plugged in. so there drawing way to much power but I have no idea why because I'm a newbie lol 

I'm going to keep looking over it and checking things out because even with it being unverified I'm sure this is no doubt a mistake I've made :o
The best substitute for intelligence is silence

slacker

I would remove the opamps and disconnect the two jumpers that go from the 6th row down to the TL072 and TLO74, this disconnects the -9 volts from the 7660 from the rest of the circuit. Power it up with just the 7660 installed and see if it still heats up, if it does the problem is somewhere around the 7660. If it doesn't get hot then see if you have about -9 volts on pin 5 of the 7660, until you get that there's no point looking any further. Once you get that working connect one of the jumpers you disconnected earlier and see if you still get -9 volts on pin 5 and that it's not over heating, if it starts overheating the problem is around the jumper you just connected. If it seems ok put in the opamp for the jumper you connected and see if it still works ok. Do the same thing for the other jumper and opamp.