Good day folks,
I got this Lazar EV1804D, came in in protect.
It seems to have previous work done on it. I repaired the PS and got that up, (114vdc rails, +/-15v, and +5V). I don't have any oscillation on the output FETs, all output FETs (IRFB4227) are out of the circuit.
The class D card is a 13 pin version and is fully encapsulated in a black epoxy. I haven't come across this 13pin variant of the class D card.
Below are some pin voltages, and what I traced for the 13 pin card (left to right ref to center tap sec transformer)
1: +15v
2: 1.59 vdc (spk out)
3: 1.51v
4: audio in
5: +5v
6: 6 mv (gnd/center tap of transformer sec.)
7: -15v
8: -58v
9: 1.58v (gate drive)
10: -44v
11: +58v
12: 1.58v (gate drive)
13: -58v
Anyone worked with this amplifier/driver card before and willing to assist?
I got this Lazar EV1804D, came in in protect.
It seems to have previous work done on it. I repaired the PS and got that up, (114vdc rails, +/-15v, and +5V). I don't have any oscillation on the output FETs, all output FETs (IRFB4227) are out of the circuit.
The class D card is a 13 pin version and is fully encapsulated in a black epoxy. I haven't come across this 13pin variant of the class D card.
Below are some pin voltages, and what I traced for the 13 pin card (left to right ref to center tap sec transformer)
1: +15v
2: 1.59 vdc (spk out)
3: 1.51v
4: audio in
5: +5v
6: 6 mv (gnd/center tap of transformer sec.)
7: -15v
8: -58v
9: 1.58v (gate drive)
10: -44v
11: +58v
12: 1.58v (gate drive)
13: -58v
Anyone worked with this amplifier/driver card before and willing to assist?
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I'm not very familiar with this amplifier.
The first thing I do when those driver boards have some kind of epoxy on it (maybe someone has a better way), is first heath up the epoxy a bit with a hot air gun. Then I scrub some acetone on the epoxy with a tooth brush for maybe 2 times (with 5 minutes break in between).
Then the glue is way nore easy to remove.
The first thing I do when those driver boards have some kind of epoxy on it (maybe someone has a better way), is first heath up the epoxy a bit with a hot air gun. Then I scrub some acetone on the epoxy with a tooth brush for maybe 2 times (with 5 minutes break in between).
Then the glue is way nore easy to remove.