Bought this MTX 1000D monoblock from ebay broken. The amp powers on but there is no sound just static noise goes to speakers.
I checked all FETs they are all good, as well nothing looks burned on the board exept one diode that I checked and it is still good the D446 (MUR1540).
But looks like someone was fixing it, installed the capacitor 220uf on the U141 (THAT 2155) and also 50ohm resistor under it.
Does anybody know where I should start?
I checked all FETs they are all good, as well nothing looks burned on the board exept one diode that I checked and it is still good the D446 (MUR1540).
But looks like someone was fixing it, installed the capacitor 220uf on the U141 (THAT 2155) and also 50ohm resistor under it.
Does anybody know where I should start?
An externally hosted image should be here but it was not working when we last tested it.
Does LED238 light up?
Do you have a scope?
If that amp uses SSP45N20As in the audio section, clamp the power transistors down and never apply power without having them clamped down. If the output transistors fail, the amp may be VERY difficult to repair. These amps are VERY sensitive to changes and it's VERY difficult to find replacement FETs. Even if you find some NOS SSP45N20As, they may not work.
Do you have a scope?
If that amp uses SSP45N20As in the audio section, clamp the power transistors down and never apply power without having them clamped down. If the output transistors fail, the amp may be VERY difficult to repair. These amps are VERY sensitive to changes and it's VERY difficult to find replacement FETs. Even if you find some NOS SSP45N20As, they may not work.
good idea with the fuse thing, next time I will use it. Yes two output ssp45N20a blew up too, as well as all power FETs. Subwoofer blew too, this may be the cause.
But why did I have static noise before things blew up?
I have extra power FETs but for ssp45N20a I have nothing, what would be OK replacement for them, I know you say they are hard to find
These amps can be very difficult to repair when the outputs have to be replaced. Even when I have one on the bench, it can be very time consuming to repair. At one time, I considered making a clocked drive circuit board for them to make them easier to repair but I don't see enough of them to make it worth the time.
It's nothing personal. These amps can be very difficult to repair when the outputs need to be replaced. The other amps were easy to repair.
I learned the hard way that these aren't generally worth the time. I've tried exact replacements (NOS) as well as other FETs and generally had lots of problems. In the same amps, I tried a set of old, used outputs that were from another amp and the amps worked fine. I went back to the replacement/substitute outputs (including exact replacements) and the amps would not work properly.
I learned the hard way that these aren't generally worth the time. I've tried exact replacements (NOS) as well as other FETs and generally had lots of problems. In the same amps, I tried a set of old, used outputs that were from another amp and the amps worked fine. I went back to the replacement/substitute outputs (including exact replacements) and the amps would not work properly.
I've always been a fan of Rockford amps. Sure, they made a few turkeys but for the most part, they've made good quality amplifiers that are good for 20+ years if used as they were designed to be used (no 2 ohm mono on an amp rated only for 4 ohms mono). The new stuff is still pretty good and you can generally buy them for just a bit more than the cheap amps.
Thanks a lot man. These MTX amps all have parasitic load of .050 amp when connected power remote off, that is high enough to drain the car battery if left for a week without driving. How are Rockford amps with this?
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