Carver M500t Diagnosis and Repair

[@bsdjunkie1805]

I like your honesty and transparency, the faux pa with the positive grounding on the output would have ended up on the cutting room floor of most creators, but including it is a valuable tip for others not familiar with these amps, thank you for your time, when you're filming a fix it takes at least ten times longer than normal

[@raygianelli3612]

Thanks BSD. Humans make mistakes. A good tech learns from them, and if they are bad enough to cause damage, can fix them. I haven't made every mistake there is to make, but I'm working on it!

[@briang.7206]

Thx Ray for taking us step by step in repairing that amp it has an unusual design.

[@bill_p2074]

I like your acrylic easel - it allows you to work easier and allows us to follow your analysis.

[@raygianelli3612]

Thanks Joseph. It sure beats the cardboard box I used to use. Although that one did double duty, since it housed my spare A/C filters. :)

[@santospoland]

Great video as always Ray! The troubleshooting steps/process you undertook reminds me of a general troubleshooting principal called PAIR; Probe Analyze Isolate Resolve. It works very well when it is undertaken by someone well versed in the subject matter at hand. As you say from time to time in your videos, read and learn, engage in the subject matter… how true! When a strong background on this subject or any subject is harnessed then general troubleshooting principals like PAIR become a great partner at resolving even the toughest of issue. Thanks for sharing your knowledge with us, experienced and non alike, all that you've learned and continue to learn. Keep up the great work!

[@ianmacpherson8385]

Ray, I have limited technical ability at board level repairs. Your video was a super learning experience. Even this novice understood your concise and informed troubleshooting repair process. Well done, thoroughly entertaining.........new subscriber now!!😊✌

[@raygianelli3612]

Thanks Ian! The idea is to pass on all I've learned. As I like to say, this is the only way technicians can reproduce.

[@dirtydon8661]

Excellent fault finding end explanations! Thanks Ray

[@kevin.graham8628]

Excellent repair Ray, and very good troubleshooting advice. Really appreciate the effort you put into them.

[@texdentist]

Nice detective work, Ray. Another interesting video.

[@josephlalock8378]

i love your videos ray. i like the way you explain things and you don't get as long winded as some, not that there's anything wrong with that, i enjoy that too but in moderation. keep on making them and i'll keep on watching them. take care!

[@raygianelli3612]

It's a fine line. I don't want to give short shrift to anything, but I don't want folks glazing over either. That's why I don't make long videos. Thanks for the feedback!

[@HipocratesAG]

Man your videos are pure gold, great content and I they are getting better and better, great job not only on the unit, but with the videos. I really hope that you like to make them as much as we like to watch them.

[@gime3steps]

I loved that troubleshooting, very interesting, and interesting on the relationship of the speaker out, dumb question I don't understand the purpose , thanks Ray, great video

[@raygianelli3612]

This 250 watt/channel stereo amplifier can configured as a single channel amp putting out 700 watts. Great for driving subwoofers or, if you have two, a powerful stereo setup.

[@jebrehbaker8613]

Well done. Will share with the Facebook group!

[@jaymay9709]

Thank you for the great video. It is very helpfuel that you include the thought process and schematic interpretations. I can learn a lot from your channel ( new subscriber). I'm not familiar with the phrase "magnetic field power supply" or why it wouldn't play well with the dim bulb current limiter. Thanks again.

[@raygianelli3612]

Thanks Jay! I feel it's so important to really understand the troubleshooting process, because once you do you can apply it to anything you work on. The magnetic field power supply has an active circuit that fires a triac for voltage control. Do a search on it.

[@marc49lewis]

Very good video. As usual Carver comes up with some bizarre non-standard way of doing things. :-)

[@raygianelli3612]

I thought so too, but have since learned that this is pretty common is car audio. Even so, 30 seconds looking at the back panel would have saved me an hour of needless troubleshooting. Chalk it up to a learning experience. We're ALL still learning!

[@robertcox5228]

Hi The best troubleshooting guide is experience. Knowing where to look and what to expect will guide you to the problem, unless Murphy comes to play

[@raygianelli3612]

Too true. I should have sufficient experience by the time I'm about 150. 😳

[@IndianaDoug]

Ya there’s plenty on KZbin, but maybe 1/3 know what they’re doing. Thanks for the education. Sub’d👍🏻

[@frankgeeraerts6243]

Hello Ray , ...BOB does it always different ..........must be his benchmark ....something riding the fine line between genius and hahahaha........ Have a nice day. and thank you !

[@raygianelli3612]

I hold him in high regard, but troubleshooting some of his designs requires a specific skill set. Which, depending on the item, is one I may not yet have. Fortunately in this case it was the protection circuit, which is a pretty common design.

[@ItsaRomethingeveryday]

Complete audiophile veteran here, Subbd, Liked content

[@johnpurcell7728]

Ray, thanks for the informative video. It appears the amp still has an issue based on input current draw. Under test you were driving 170 watts per channel, or 340 watts total. If the amp was only 50% efficient that would be 680 watts line draw. But you were at 16 amps, which, at an assumed 120V RMS line, is 1920 watts. No way an M-500 draws that much power even at full rated output. But perhaps I misheard the numbers.

[@raygianelli3612]

You heard right. Unfortunately the amp is no longer here. The magnetic field power supply is not something I'm familiar with, but it supposedly they draw current as needed and not stored in large filter caps. And I believe that steady state signals stress them more than conventional designs. I'll do some more testing next time one comes my way. Meantime, owner says it's working fine.

[@coldfinger459sub0]

Thank you for going over this schematics and explaining how to circuit path works and how things get triggered and switched off and on. This is very helpful for a novelist hobbyist in electronics that just could not remember formulas in electronics class and do all the math but enjoyed fixing things and building things. New subscriber

[@Luke-12V]

Verry nice ,thanx,i lowe you videos👍💯🤩

[@Trucam2020]

As usall great video. Thanks.

[@officialmikethompson]

And as I’ve just discovered with an M-500T on the bench, they suffer horribly from cold solder joints. That alone was preventing the relay from actuating.

[@raygianelli3612]

Interesting. I wonder if that's a common occurrence with these amps? Thanks for posting this, Mike!

[@johnvanwinkle4351]

First thing I noticed is that is not the original relay. Did it just quit working before or after the relay was replaced?

[@johnvanwinkle4351]

Not surprised on the fault. He has the original caps in it. Needs recapped.

[@meraydin1]

Hi Ray, I enjoy your videos, thanks, I have one question + suggestion: Q. Will you be responsible if you dont say something like "if you are following along, you are doing it at your own risk"? is this a legal obligation or just good will? Suggestion: Please dont use those sharpies when drawing something, they make a terrible noise :)

[@raygianelli3612]

Not sure, but in out litigious society it wouldn't surprise me. I'll see if I can find noise canceling Sharpies. :)

[@Wil_Bloodworth]

Quick question Ray... what is the reason you aren't using the signal generator built into your Levear? Is it just a matter of ease of use with the other one you're using?

[@raygianelli3612]

I was having issues with the internal generator, which was later remedied with some parts purchased from excellent tech and all around nice guy Phil (PAC1085).

[@Wil_Bloodworth]

@@raygianelli3612 as an aside... the back of that carver even has a diagram to the right of the speaker terminals showing that red goes to + for both left and right... even though the diagram in line with the terminals shows the bottom-left red terminal going to ground... so confusing. I wouldn't have figured this out!

[@basspig]

That's why you need to have a floating dummy load with an analyzer connected that also has a floating ground.

[@raygianelli3612]

You're' right. I do. And it does. But even though the ground is floating, the terminals between left and right on the analyzer are common. That's where the trouble came in.

[@basspig]

@@raygianelli3612 Oops. The inputs on my R&S are totally isolated. Never had this problem with any Carver amps and also lots of bridged amps. Maybe there's an option strap that separates that ground?

[@raygianelli3612]

@@basspig No straps externally. But it's no Rohde and Schwarz either. :)

[@basspig]

@@raygianelli3612 Ah that's unfortunate. Rather limiting to the ability to test some oddball amps. The UPV is totally isolated so I can flip the polarity of one channel without causing a short circuit to the other. BTW, nice work on the troubleshooting. I like your honest approach.