Hello, new here from Maryland. I have a mrp-m500 that has been good to be for quite some time now. Recently it started acting up. It will just stop playing music randomly. Sometimes it’ll be fine for a little sometimes it’ll happen after a few minutes. Usually after I reset it by u plugging the remote wire it’ll work again but eventually cuts off(sometimes it works fine for a long time).
I’m new to this but I have a good grasp on soldering, using a multimeter and am technically inclined. I have started troubleshooting using posts from here and watching videos. I bought a MESR-100 to test caps while in circuit. If I did the test right they were all good. I tried applying new thermal compound to mosfets to see if they were overheating but that didn’t help. Im in the process of testing all of the ceramic fuses(I think that’s what they are called) and I think they are all good. I use the continuity setting and listen for a tone. I’m not really sure what else to check. I know it’s not worth fixing, but I’m just trying to learn and would love to at least find the issue.
Thanks!
I’m new to this but I have a good grasp on soldering, using a multimeter and am technically inclined. I have started troubleshooting using posts from here and watching videos. I bought a MESR-100 to test caps while in circuit. If I did the test right they were all good. I tried applying new thermal compound to mosfets to see if they were overheating but that didn’t help. Im in the process of testing all of the ceramic fuses(I think that’s what they are called) and I think they are all good. I use the continuity setting and listen for a tone. I’m not really sure what else to check. I know it’s not worth fixing, but I’m just trying to learn and would love to at least find the issue.
Thanks!
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Thanks for the reply Perry! I’m sorry I should have gone into more detail about what I have done so far. This amp has been in my truck for maybe 10 years working fine. After it started acting up I tried a new line out converter and it did the same thing. Moved it to my wife’s car using new wiring and another line out converter, same thing, put it in my friends car with a aftermarket radio, same thing. It’s got to be the amp. I am currently waiting on a bench power supply so that I can test out of car.
When you get it powered up and playing on the bench, move the two output filter inductors to see if that causes the amp to have problems.
What power supply did you order?
What power supply did you order?
I’m assuming those are the two things with a copper wire around it. Is it going to shock me? Lol sorry if that’s a dumb question. Still learning.
I got this one. Not super expensive but it got good reviews. Let me know what you think.
https://a.co/d/0OyJvJQ
I got this one. Not super expensive but it got good reviews. Let me know what you think.
https://a.co/d/0OyJvJQ
If you're ever concerned about being shocked, use a non-conductive probe (dowel, bamboo skewer...). You use the same probes when pushing on various parts of the board or other components, not so much to prevent shock but because the conductivity of your skin can affect the operation of the circuit.
The inductors (yes, toroidal dark red cores, wound with enamel wire) may appear to have bare wire but it's insulated.
Still learning? I've been doing this since about 1986 and still have much to learn.
The inductors (yes, toroidal dark red cores, wound with enamel wire) may appear to have bare wire but it's insulated.
Still learning? I've been doing this since about 1986 and still have much to learn.
Ok once the power supply comes in I will try that! I did you a continuity test on them. Not sure if that tells anything. But it checked good. Thank you!
A continuity test can be inconclusive because there can be intermittent connections (either shorts or opens). Either can cause the amp to shut down.
Ok used my new power supply and a speaker to play some music on the bench. Wiggled the inductors no change. Music just stops randomly. Cycling power will eventually get music back playing but stops again.
Does it do this at low volume (well below the current capacity of the supply)?
Do any of the potentiometers or switches seem to be intermittent?
Does the power supply shut down when you lose audio?
Do any of the potentiometers or switches seem to be intermittent?
Does the power supply shut down when you lose audio?
Yes does it any any volume. I wiggled and adjust switches, nothing changed. Power supply does not turn off.
I don't really recommend scopes (no one would buy most of what I'd suggest) but if you want a decent USB scope that you would use with a computer, the OWON VDS1022I (<<< the I is very important as it signifies 'isolated') is the cheapest scope that I've found that will do any useful work.
We may be able to get by, for now, without one.
Do you have a multimeter?
What are you using to drive a signal into your amp?
We may be able to get by, for now, without one.
Do you have a multimeter?
What are you using to drive a signal into your amp?
What were you using in the vehicle when the amp was intermittently working?
Have you ever had audio from the amp when using the cell phone?
Play something through the phone at a moderately high level. With the meter across the center conductor and the shield, can you see the meter changing while playing... whatever?
Have you ever had audio from the amp when using the cell phone?
Play something through the phone at a moderately high level. With the meter across the center conductor and the shield, can you see the meter changing while playing... whatever?
Using the radio to a dsp. Changed to a different dsp and same issue. Changed to straight from radio, same issue.
Audio from phone did work when amp would always work. This is just my sub amp.
What’s the center conductor? Sorry….
Audio from phone did work when amp would always work. This is just my sub amp.
What’s the center conductor? Sorry….
