Memphis-ST1000D Amp Problem
 

Mods, sorry if this is in the wrong place, it's been awhile since I've been on the site.

Anyways, my friend has a Memphis Audio 16-ST1000D Amp, seen here on ampguts:

http://ampguts.realmofexcursion.com/Memphis_16-ST1000D/

After loosing his old MTX Subs from playing them past there limit, he purchased another sub to take the 1ohm load. Anyways, while we were hooking the new sub up, we noticed the fuse light was illuminated. After checking the fuses on the underside, both 40A fuses were fried. So, we tried to find another 2 40A fuses in that style to try, only to find none. So we picked up 2 30A fuses, just to see if it would work, and try to source the problem. As soon as we got the 30A in (Gain was turned down to a minimum level, stereo was on standby) they popped, like as soon as the two terminals met the amp. Tried again, with the same result.

So, what could cause this? My reasoning was if the gain was at a minimum, and the stereo wasn't playing, you could use a lower fuse to just see if it works, as the amp wouldn't need to be fused at 40A x 2 if it wasn't playing at it's mid or maximum level. Am I wrong in this assumption, or is there something wrong internally with the amp (A friend said it could be a problem with the power supply thing in the amp)}

Thanks in advance for any responses, both myself and my friend appreciate it.

Hodder

so you were hooking up the sub with the amp on? It sounds like the amp is seeing a short when you hook up the sub, I would check to make sure your voice coils are wired right and check to see the impedance with a DMM to make sure that the sub is not showing a short.

Thanks for the quick reply, we'll try that!

Wait a sec, the fuse light was on before we even hooked up the sub.Could that rule out the short?

yes and no, could be a short on the amp, or grounding problem? so the fuses pop the second they are installed? I assume you are doing this with the car off right?

I'll have to ask him, I was only present before we got the 30A fuses haha.

was this existing in the car or is this a new amp install?
I assumed it was working before you added the new sub?

The amp stayed in the same car, and was working the last time he had his old sub hooked up.

alright, unless something has changed I am confused, really sounds like somthing is shorting, that's about all that would pop the fuse.
Hopefully some of the more experienced guys on here can comment.

Double check your voltage and connections at the amp to make sure there isn't a frayed wire touching something it shouldn't be. If they check out fine, the amplifier's power supply or output stage probably has something wrong with it.

You can have the amplifier repaired if it's under warranty?

Hope this helps.

It's not under warrenty, he bought it used about a year ago from a member this site. We'll check the wires and get back.

In the meantime, if the power supply or output stage is meessed up, is it just as well to find another amp, or would it be feasible to fix.

It's a good enough amp that it would be worth spending $20 or so to have it checked out if the wiring is not the issue.....:smokin:

Ok, so we looked at it tonight. Measured voltage at the amp terminals was 12.6V. Measured final resistance was 1.0 to 1.1 Ohms. We disconnected the positive cable from the amp, and put two 20A fuses in (Since we didn't have 2 40's) When the power supply was re-connected, all was good, no fuse fault like as before. However as soon as we turned the HU on, two of the fuses popped.

Your friend's amp is broken and will need to be repaired. If it didn't burn anything too badly, around $100 - $200 should fix it.

Good luck!