Need help bringing D2 back to life

[hollywood084]

To make a long story short, my D2 has been out of service for about 6 years and I'm looking to resurrect it. I'm no electronic tech, but I personally think (knowing the history behind the amp) it's either not receiving an audio signal from the HU (via the rca input jacks on the amp), or it's not pushing out the signal to the sub from the speaker output part (no power or something.) I really don't think it's anything between there, but I won't rule anything out since I don't know a whole lot.

Imageshack - 20405575.jpg
Imageshack - 45224171.jpg

One of the parts in question is the one right between the two gold speaker outputs, in front of the big orange thing. Now apparently, if I remember correctly (it was 6-7 years ago) the guy who worked on it says he cut it (for some reason, to test something I think) but it shouldn't be the reason it's not working at all now. Quick note, the amp worked BEFORE I sent it to the guy, when I got it back it didn't work at all.

Apparently the only part that was worked on/replaced is the RCA inputs (to the left in one of the above pics.) Is there any way I can see if the amplifier is receiving a signal through those?

How I can test with a multimeter to see if the amp is pushing out power through the speaker outputs pictured above, to the sub.

As far as I can remember, the amp did NOT go into protect mode when hooked up.

Thanks in advance. Any help is greatly appreciated.

[hollywood084]

Here's some pics. This link has some general pics or the areas in question D2 pictures by hw98 - Photobucket

and this one has some of some part that looks kind of weird and out of place, it's on the back of the board. Some pictures are of the top down view so you can see where it fits in the grand scheme (it says THR1 upside down)
D2 Weird part pictures by hw98 - Photobucket

[1moreamp]

[QUOTE=hollywood084;2077463 I'm no electronic tech, but I personally think (knowing the history behind the amp) it's either not receiving an audio signal from the HU (via the rca input jacks on the amp), or it's not pushing out the signal to the sub from the speaker output part (no power or something.) I really don't think it's anything between there, but I won't rule anything out since I don't know a whole lot.

Thanks in advance. Any help is greatly appreciated.[/QUOTE]




Well you don't really need to be an electronics tech to fix this amp but it sure would help like hello,... if you understand where I coming from. I have repaired a few of these myself and they can be tricky at best to even a seasoned tech. Everybody has had fun working on these.

I will tell you this much they usually go silent because of a bad fet driver chip. The HIP-4080AIP to be exact. You can find it easily cause its usually the only socketed chip for ease of replacement.< oh and many times its top has had its numbers brushed off to protect the untrained from being able to repair this amp >This amp as I recall has two chips polished one is only 8 pins and it drives the power supply fets, not the audio amp fets.
This amp needs to be installed back into its sink to be worked on in most cases as any real signal testing can cause overheating without the aluminum there to adsorb and emit the excessive heat if any on the power devices. You might get lucky and not have it smoke up on you but I would not push my own luck like this so I say put int back together and attach it to the sink properly while testing and working on this amp. Also be warned this amp has enough juice inside of it to seriously hurt you, and others around you, let alone blow the tips off your voltmeter probes....

Your pics are not what I would need to see, and I have not expanded them but if the 4080 was defective you may or may not get a protection light. And without a very trusty voltmeter and some experience with Orange things (Mylar capacitor by the way ), Your most likely going to have tons of trouble fixing this exact amp.

I see you leaning towards the RCAs but the amp would still be making all kinds of funny noises if the RCAs were damaged in most cases. Your speaker would be jumping all around and all sorts of unwanted noise would be presented to your ears for broken grounds or weak tip connections. So not to completely rule it out, but to gain to proper perspective on the possibility of this being as easy as a set of RCA jacks, I add my 2 cents worth of input. I don't think so....You can use the ohms or continuity range of your meter to check for a solid signal pathway. But here agin I am very doutbful this will be the issue.

As for the cut thing well that tech probably cut the ceramic resistor attached that Orange mylar cap, and by doing so he removed a very important filter at the output of the amp,( they tend to run very hot) but this would not cause the amp to go silent. It would most likely cause over-heating of your voice coils on you subs because this output filter is supposed to remove unwanted bandwidth signals from the output and provide a stable load situation to the amp in most cases. Now why he would cut it out is a very speculative question with answers ranging from the simple to the insultingly absurd, but the resistor was meant to be there by the designer or they would have removed it.
So I again here beg to digress as it may become impolite of me to express any guess's about why he would CUT the thing out in the first place...

Yes you could read the output AC and DC voltage across the speaker terminals but with the amp being silent I am doubtful you will glean much usable info. I myself would want to see if you had DC voltage out and how much, and if it was playing at all the output AC voltage would only be useful to figure out how much power the amp was pushing into your speaker load.

Perry has a web-site Basic Amplifier Repair
I suggest you click your way through a few of his well documented pages to gain a higher perspective. He has already posted tons of valuable training info there to brace you for the experience your D2 is going to put you through while being revisited and revived by you instead of a veteran tech or the original builder.

I'm not trying to put you off, but I am trying to aim your energy to a place I know a ton of valuable info will be presented to you at a rate at which you can adsorb it at your own speed. The level you sound to be at right now will take considerable hand holding to get you safely through a few of the very basic test steps required to gain a proper technical perspective of what is wrong with your silent amp. Most of which you can read you own way through on Perry's web site, again at your own speed. Any questions you may have and their will be dozens will most likely be easily answered by myself or others here once you have read through the course over at BCAE...I even think Perry has a exact page for this very amp as I recall.

Please try the link to gain a huge step ahead of where you are currently. We will all be here to help you once you have the bigger picture that will be well explained over on the site. Heck I myself would be glad to be of help further once your up to speed and well read on this effort...Hope to be of help to you more....

[hollywood084]

I appreciate the in depth post, I might just send it out to perry because this post and his page have enlightened me as to what it will take to fully test this thing out. I don't really have the time/desire to learn all that lol. I can handle replacing a few parts, but getting there is a different story :P

[1moreamp]

Sounds good, you may be making a very wise choice. I base this on my experiences inside these for others. Plus it would be nice to see you happy again with as little effort and time involvement as possible.
It all comes down to how much is your time worth, and how long do you want to spend on this project. Perry might have it running a in few minutes or a few hours but I know he will test it completely before returning it to you. I hope I have helped some at least....C

[hollywood084]

You helped a ton actually. I appreciate it.