OS Mmats D3000.1 repair
So I got a good deal on this amp blown. The power supply is smoked and there seems to be some "mods" done to it.
I need to verify that the components in the amp are correct.
The PS transistors are all mixed up: HRF3205, IRFZ44R, and IRF3205. Which one type should I replace them with?
The main PS driver IC is SG3525A. The transistor drivers are MIC4424CN on one side and MIC4424YN on the other. The one on the 4424CN side has 2 components removed and a different resistor used and a zenner attached to the top of it.
Also I seem to have some diodes directly connecting the transformer to the PS transistors... should this be?
Attachment 307640Attachment 307641
There is also 2 resistors that appear to be connecting/or bypassing something to the 3525.
What should I use to replace the PS transistors?
Are the other driver ICs the right components?
What is that missing component on D70? It is likely the same as D72? "SCM"
Attachment 307639Attachment 307643
There are IRFB4710 output transistors installed, is this the correct ones?
The output driver IC is a HIP4080AIP, is this the correct one?
I wanna return it back to factory or slightly better than condition. Thanks in advance. :)
I don't know what the original PS FETs were but I'd use IRF3205s as replacements.
The large diodes under the board are on top of the board on other versions. The small SMD diodes are not installed in the photos that I have.
I don't know what the resistors on the bottom of the board are for. I've never seen them. They appear to be on pins 7 and 11 and appear to be soldered to ground. That's not commonly done on this IC. There is a resistor that's connected between 7 and 5 on most amps that use this IC. It's generally between 68 ohms and 220 ohms.
The 4710s and the 4080 are the right components but I've had trouble with reliability with the replacement 4710s that I've purchased. I've had much better luck with the IRF3701Zs. IF you can't get the 4710s to survive basic testing, try the 3710Zs.
Awesome sir, thank you... I'll just order the 3701Z's right from the start.
One of the resistors under the board is not soldered down so it could very well need to be soldered to pin 5? I'll check the resistor values in the morning.
Also, the end of one of them diodes from the transformer isn't connected to a transistor, its just floating as seen on the right in this photo.
One of the RURG3060C dual diodes blew its leg off, lol, as seen here.
Thinking I'm gonna have to replace it too, lol.
Thanks again Perry. :)
Perry could you possibly send me some of the pics you have of the amp? and/or any other data would be greatly appreciated.
I don't know how you're posting the photos but it takes you to a new window and will delete all text. If someone is trying to reply and goes back to look at a photo, it will delete all that they have typed. I always check this or copy the text before I on a photo but others may not realize that there is a problem. Are you using the 'Go Advanced' button then uploading the images via the 'manage attachements' button?
You should know that the 3710Zs are rated for significantly less current and if the owner of this amp insists on running it at 1/4 ohm like all of the people that I've had to deal with, they may not survive.
I've dumped a zipped file in the following folder. These are at reduced resolution. If you want one or more at higher resolution, let me know which one(s).
Index of /temp/mmats3000pt1
Thanks Perry. Your pics are great. Its board components are a lil different from mine but they do help greatly.
Yes, I was using the attach photo option to place them in a specific part of the text area. Not sure why its opening another page it usually would just zoom.
I bought this amp with the intent of getting another and running the pair in my van. I can run them at proper impedance (1ohm) but if I can get down to a .5 each starting load that would be ideal.
I see on the board that there is a listing for running 1 ohm or .5 where 3 resistors are. Is it simply a matter of changing to the proper resistance value to make the amp .5 stable? On my amp its R154, R166, & R167. I realize it will change its power ratings too.
Mouser appears to have the 4710's.... think I should try them? or would I be safe with the 3710's? I can't seem to find 3701z's....
The 4710s may work for you but the ones that I used did not.
The non-z version isn't likely to work. IRF3710Z click HERE.
I doubt that the 3710Z will be reliable at 0.5 ohm.
I would guess that the resistors are part of the current shunt and change the shutdown threshold. I'd use it as it is to see if it will run as is.
I've uploaded a few more photos in the same folder as the others. It is from an amp with more significant mods.
Does anyone have info on what diodes I should use from the transformers to the IRF3205 gate? These 2 amps have several different ones...
1N6277A (2 in a series)
Are you sure that the diodes go to the gates of the 3205s?
My bad... they are connected to the source. lol I was looking at the amp from the bottom when I posted.
|All times are GMT. The time now is 02:45 AM.|
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright ©1999-2016 diyAudio