I was gifted a MRD-M1005 about 6 years ago and have been using it with the same system ever since. About 3 months ago, I got in my car and I noticed my subwoofer never kicked on. I thought it was strange so I shut off my head-unit and turned it back on (power cycling the amplifiers as well). After that everything was fine. I could jam at loud levels, everything was great. About a week later, it happened again. Same thing fixed it. Over the next couple of weeks, the interval of time in which the "CUR" error occurred rapidly increased. Before I knew it, every time I turned on the car I would have to power cycle the head unit to get the subwoofer to work. Until one day, about two weeks ago, that trick didn't work.
I know I shouldn't have neglected the issue but I have been really busy. At the time, I didn't know I was getting the "CUR" error because I never checked the amps. I assumed it was my head units fault because it's old and has been getting some quirks, like the touch screen is failing. Last week, I started to address the issue and discovered the amp was showing "CUR" on the screen, the manual says that means the amp shut down due to excessive current.
When I googled the error, every site/forum I could find said it was either a bad ground wire or broken subwoofer. I have an Alpine SWX-1243D with dual 4-ohm voice coils wired in parallel. It measures 2.2 ohms on my multi-meter. The wire connecting the sub to the amp has no continuity, so it did not short or fail. I double checked all my wiring, even reconnected everything. Nothing out of the ordinary, not a single strand out of place. All the fuses looked good, but I replaced all of them with spares to rule that out. I disconnected the subwoofer and RCA cables so the only things plugged into the amp were the remote turn on lead, 12v positive, and negative wire. When it starts up it goes straight into the "CUR" error. I even pulled the amplifier out of my car and rigged up a test bench with a spare head unit and marine deep cycle battery. Every time it starts up, it goes straight to the "CUR" error (even with no RCA and no sub wires connected).
It's pretty clear to me that the issue is with my amplifier. It's a really nice amp and I would like to try to repair it but I am not too sure where to begin. I disassembled it and did a visual inspection. Nothing looks burnt or damaged. I used a computer air blower and blew off the PCB in case something small I couldn't see was shorting something. I then re-assembled it and powered it back up but it still showed "CUR".
Again, I had no issues turning up the volume high and thumping real hard. I only ever had issues getting the amp just to start without a "CUR" error. I am okay at soldering and following directions. If anyone knows what could be causing my issues or could tell me what I should be testing for, I would greatly appreciate it.
Equipment on hand:
• NO Oscilloscope
• 2 Multimeters (One is a Meterk Digital Multimeter)
• Stinger RCA cables as Signal Source from Pioneer head unit
• Soldering iron (also solder and rosin)
• Desoldering pump (and desoldering wick)
• Fully Charged Deep Cycle Battery to use as a testing Power supply
• 2 ohm current limiting resistor of unknown brand or quality
I know I shouldn't have neglected the issue but I have been really busy. At the time, I didn't know I was getting the "CUR" error because I never checked the amps. I assumed it was my head units fault because it's old and has been getting some quirks, like the touch screen is failing. Last week, I started to address the issue and discovered the amp was showing "CUR" on the screen, the manual says that means the amp shut down due to excessive current.
When I googled the error, every site/forum I could find said it was either a bad ground wire or broken subwoofer. I have an Alpine SWX-1243D with dual 4-ohm voice coils wired in parallel. It measures 2.2 ohms on my multi-meter. The wire connecting the sub to the amp has no continuity, so it did not short or fail. I double checked all my wiring, even reconnected everything. Nothing out of the ordinary, not a single strand out of place. All the fuses looked good, but I replaced all of them with spares to rule that out. I disconnected the subwoofer and RCA cables so the only things plugged into the amp were the remote turn on lead, 12v positive, and negative wire. When it starts up it goes straight into the "CUR" error. I even pulled the amplifier out of my car and rigged up a test bench with a spare head unit and marine deep cycle battery. Every time it starts up, it goes straight to the "CUR" error (even with no RCA and no sub wires connected).
It's pretty clear to me that the issue is with my amplifier. It's a really nice amp and I would like to try to repair it but I am not too sure where to begin. I disassembled it and did a visual inspection. Nothing looks burnt or damaged. I used a computer air blower and blew off the PCB in case something small I couldn't see was shorting something. I then re-assembled it and powered it back up but it still showed "CUR".
Again, I had no issues turning up the volume high and thumping real hard. I only ever had issues getting the amp just to start without a "CUR" error. I am okay at soldering and following directions. If anyone knows what could be causing my issues or could tell me what I should be testing for, I would greatly appreciate it.
Equipment on hand:
• NO Oscilloscope
• 2 Multimeters (One is a Meterk Digital Multimeter)
• Stinger RCA cables as Signal Source from Pioneer head unit
• Soldering iron (also solder and rosin)
• Desoldering pump (and desoldering wick)
• Fully Charged Deep Cycle Battery to use as a testing Power supply
• 2 ohm current limiting resistor of unknown brand or quality
Last edited:
It likely has shorted output transistors.
Search the forum for 'M1005' for other similar amp threads.
These amps can be difficult to repair because if their complexity, particularly due to the circuits involved with sequencing/protecting the audio circuit.
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)
Search the forum for 'M1005' for other similar amp threads.
These amps can be difficult to repair because if their complexity, particularly due to the circuits involved with sequencing/protecting the audio circuit.
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)
I don't know if I'm just crazy but I couldn't find "EDIT SIGNATURE" under "USER CP". I even looked all over my user settings. Regardless, I updated my first post to list the equipment I have on hand.
I searched the forum for 'M1005' and couldn't find anyone that had similar symptoms as me. Is there anyway I can test the output transistors to see if/which ones are bad? Also, are the output transistors just the ones with no heat sinks? I'm going to start looking up the part numbers I see on the transistors to get an idea of cost.
I searched the forum for 'M1005' and couldn't find anyone that had similar symptoms as me. Is there anyway I can test the output transistors to see if/which ones are bad? Also, are the output transistors just the ones with no heat sinks? I'm going to start looking up the part numbers I see on the transistors to get an idea of cost.
It may be because you're still under moderation.
You seem to be VERY new to repair work. Read the following page in its entirety (even the parts that you believe are irrelevant).
Did you read the threads that came up when you searched for m1005?
What do you mean by 'without heatsinks'? Are you referring to the clamps?
You seem to be VERY new to repair work. Read the following page in its entirety (even the parts that you believe are irrelevant).
Did you read the threads that came up when you searched for m1005?
What do you mean by 'without heatsinks'? Are you referring to the clamps?
I have the same amp in my hands waiting to be repaired but I can't manage to find time for it.
The one i've works fine until You input any signal into the RCA plugs. Then "CUR" shows up.
First of all check if any of the output transistors are shorted.
If nothing is shorted oscilloscope will be needed as You can't proceed with anything without it.
Problem could be in the protection circuit, driver modules and etc.
Perry Babin - is this amp full bridge class D ? If i'm being correct there are two IRS driver chips on the board ?
The one i've works fine until You input any signal into the RCA plugs. Then "CUR" shows up.
First of all check if any of the output transistors are shorted.
If nothing is shorted oscilloscope will be needed as You can't proceed with anything without it.
Problem could be in the protection circuit, driver modules and etc.
Perry Babin - is this amp full bridge class D ? If i'm being correct there are two IRS driver chips on the board ?
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