Tweet
Hey guys, I have an EV SB120a I got for 20 bucks that has no output. It's a 400 watt class D powered 12 inch sub. On the power amp board an IR2110 went up in smoke because someone reversed it and I found a PH PBYR 1645 schottky shorted. On the power supply board a main filter cap was reversed and took out the fuse, I reversed it and replaced the fuse, checked all of the diodes to find any shorted ones and found none. I have it hooked up to my current limiter after replacing what I found to be defective and the bulb glows bright and then goes down to nothing which is a relief. I now get a power light and have checked the 15 volt supply and it is there. Both output transistors are IRFP 440's. Everything on the output side was tested and nothing shorted and all had correct voltage drops. There is no DC on the output. Amp doesn't even make a pop sound when I turn it on. The woofer is fine as I have already tested it. I don't have a service manual for the sub. I repaired this amp a while ago for the gentleman I got it from and it worked well but since then he has had his friend take a look at it and now I'm stumped! If anyone can direct me what to look for next I'm listening!
-
-
Here's a schematic: ElectroVoice-SB120a actspk.pdfOriginally posted by Enzo
-
Thanks for the service manual! I spent a little time looking through it and my model seems to be pretty different by looking at the layouts. Do you happen to know if they made different versions of the circuit boards as the years went by? I believe mine is an earlier revision of the circuit board. I'll dig into the schematics in the manual and see if they match my boards.Comment
Comment