What makes an Amp go into Standby ?

[beardog03]

I realize that a bad ground or something like that would make it trip, but it has not moved or been in any way changed or messed with fro quite some time, so.....


What makes an Amp trip intostandby mode ?
Why does the overheated light come on when the amp is not even warm to the touch...it`s ice cold

I have located a pristine amp to replace it with, and I`m working on it as we speak, but I hate to just toss this one out if it`s fixable....

I`m using a Dennon 3802 pre/pro and a T.O.L Yammie CDP
AQ Diamondback I/C`s (new)
and Regular 12 ga Monster cable fro surrounds and AQ Type 4 for the Center..
I will be using all type 4 when I`m done, but I digress

All Polk LSi speaks..

I`m going to pop the top and take a peek....where do I start...besides the obvious ?

[hoosier21]

the protection system can go bad, nothing wrong with the amp, the protection goes bad.

could be anything

[beardog03]

I was afraid you were going to say that !!!

[Keiko]

I was having a similar issue recently with my receiver not long ago beardog. I think I have a bad ground or something with the wall outlet. I just used a different one and haven't had a problem yet. ( Knock on wood) Might be a long shot but you can try that. A short in the speaker wire or the wires touching could cause that to. Good luck.

[beardog03]

The first thing I tried was switching outlets...
It worked for a litte while..

Then I went through the speaker cables to make sure nothing was touching...

I think I need to open her up and see if something is fried, or got inside somehow..

I just hate to start messing around without some sort of direction


It wa sdropped , literally , at my feet...by the DHL guy
The clown I bought it from sent it from texas wrapped in two pillows !!

He said he was going to file a claim, but then just disappeared from the forum....(mesquitehead)(sp)

It has done fine for the last year, but I figured I was pushing my luck by going that long

Man I tought the HT rig was done for a while !!
Guess I was wrong ....

[dudeinaroom]

could be a thermal couple for the heat sensing circuit. Did you check the connections inside your speaker??

[beardog03]

No...

I figured since the LSi`s are fairly new that they wouldn`t be the problem...

I guess they could be...yes ?

[dudeinaroom]

never know, is the amp 4 ohm stable?

[dorokusai]

The owner is usually the culprit.

[WilliamM2]

Find a decent tech to take a look at it. My old Parasound was constantly going into "protect" mode a couple of years ago. There is a twelve volt signal that turned on the relay (not to be confused with a 12v trigger, it didn't have one), there was a bad cap in the twelve volt circuit, causing it to lose power, and open the relay. Total cost of repair? $0.52 in parts.

[Vr3MxStyler2k3]

gremlins

[shadowofnight]

Opening her up can fix a lot of obvious problems as well as discrete component type problems where you can follow the normal circuit flow....but like in Williams case, A parameter needed to be met ( 12 volts to the relay ) and it wasnt, this is where the schematics for the amp would be needed.

[shadowofnight]

See if these guys have your particular amp's schematic/service manual

http://www.antechlabs.com/servicemanuals.htm

[dudeinaroom]

gremlins

I totally forgot about then, good call:D

[beardog03]

yes it is 4 ohm stable....

Mark is probably right, it could be operator error


And I did find a gremlin in the dennon..


I also have a pending sale on an absolutly minty, less than 80 hrs old replacement..

I`m gonna see if Shadow wants to help me rebuild this one....or somebody that knows what they are doing to help build a F1 version of it`s former self !!

[billbillw]

beardog,
Parasound will email the schematic to you. Call them and talk to Tony Pointes. He may also give you some advice on which part of the circuit to focus on. FYI: Parasound doesn't really produce "service manuals", just the schematics. One good think, amps like this are generally are built from of many inexpensive parts (appart from the large caps and transformers). No high dollar digital boards to replace. That's why they are almost always worth fixing.

[beardog03]

I`ll post a pic in a few minutes...I think I found the problem..

A cap has leaked the brown stuff out the bottm of it..
and it`s right on the top board...easy to get to..

Thanks for the hook-up..
I will get ahold of Tony and get the schematics Monday

[shadowofnight]

beardog,
Parasound will email the schematic to you. Call them and talk to Tony Pointes. He may also give you some advice on which part of the circuit to focus on. FYI: Parasound doesn't really produce "service manuals", just the schematics. One good think, amps like this are generally are built from of many inexpensive parts (appart from the large caps and transformers). No high dollar digital boards to replace. That's why they are almost always worth fixing.


This amp looks extremely simple inside....One big ass toroidal transformer...one control board and 5 redundant single board amplifiers sharing one chassis...see the picture I posted above....as simple as they come for multiple channel amps.

[beardog03]

In looking a little closer, I found that Pairs of the light blue caps on each board have been leaking...

I am still looking forward to "rebuilding" this amp....it will be a great learning experience..

It does seem pretty sraight forward inside, as you say...

I am wondering why they are leaking...what was the cause of the problem ?

[dorokusai]

That should be pretty easy to fix. Don't overthink things and believe that everything must be completely rebuilt and upgraded. I would suggest a suitable replacement, perhaps better, capacitor and just fix the problem.

We're talking about the 2205 right?

[beardog03]

some pic`s...

[beardog03]

Mark,

Yes...the 2205a
I think that with some guidence, it shouldn`t be too bad

[dorokusai]

You're smart, you don't need 50 emails and 4 phone calls to replace a capacitor.

[beardog03]

waaaaaaaaaaaa

thanks bro !

I just need some suggestions as to brand to "upgrade " if necessary


Thanks to you, I love me Parasounds !!!

[dorokusai]

Solen.

[shadowofnight]

If they are the same caps on each individual single channel ....it could have been a bad batch of smaller electrolytics...A few years back I had to change out about 30 or so Dell motherboards in the 400SC server systems...bad batches of electrolytic caps . They were cheaply made...couldnt handle the application they SHOULD have been able to according to their rated thermal/electrical markings...and the pressure was building up inside as the electrolyte failed ...some just bulged...some popped their safety vents and leaked ....even the ones that just bulged sometimes internally shorted and failed.

Look at this link http://www.news.com/PCs-plagued-by-bad-capacitors/2100-1041_3-5942647.html?tag=nefd.lede I saved it from a while back...scroll down and click on the picture of the caps that says click to view....see if your caps look the same as you scroll through the pics.

Luckily they are easy to change out......piece of cake...she will live again :)

[GV#27]

For replacement caps I would look at the very good and inexpensive Panasonic FC series caps from Digi Key.Make sure they are the same value of capactance and at least the same voltage.

[shadowofnight]

Ha...I was typing as you were posting the pics....easy fix....you did stay at a Holiday Inn Express this year right ? :D

[GV#27]

Here is a link to Digi Key.http://www.digikey.com/ You can order a free catalog it is huge.

BTW,The Panasonic FC caps I mentioned are low impedance electrolytics and are superior parts to the stock ones.They are excellent for local power supply decoupling which is likely what the purpose of those are in the amp.

[beardog03]

Thanks for all the help guys..

yeah, thay are all the same ones on each board

They all leaked from the top or bottom

I`m starting to feel better now ...:o

I`m waiting to hear from the guy with my new replacement amp..

It`s making me crazy waiting like this..!!!

[beardog03]

Cataloge Request Submitd

[shadowofnight]

yeah, thay are all the same ones on each board

That for sure points to a really bad batch of caps...or Parasound used the wrong cap for the job ( More likely bad batch ) ...either way I would contact them even out of warranty. When its obvious that each board failed in the exact same way....most of the better manufacturers would help you in that situation...point them to this thread as well.

One more thing....I would for sure pop the top of the new amp you are getting to just look for this same issue....it possibly could have been manufactured with the same batch of internal single channel amps.

[ka7niq]

I`ll post a pic in a few minutes...I think I found the problem..

A cap has leaked the brown stuff out the bottm of it..
and it`s right on the top board...easy to get to..

Thanks for the hook-up..
I will get ahold of Tony and get the schematics Monday
My Adcom 585 Input Board Capacitors leaked BearDog.
The electrolyte can destroy the board, get it wiped off asap

[beardog03]

I was wondering about that...
What should I use to clean the board with ?

Denatured alchol ?

Shadow,
I go to pick up the new one at 3 pm
I will definately look into that...I was thinking the same thing...

maybe I will upgrade both and Bi-Amp the LSi`s
That would be nice !!

[GV#27]

I was wondering about that...
What should I use to clean the board with ?


Methalhydrate should work.

bear, are you certain it is electrolyte and not just epoxy used to keep the caps secure to the board?Sometimes epoxy is used for this purpose and can look like a leaky cap,just a thought.A leaky cap will smell bad,like dead fish:eek:
Do any of the caps look swelled or have any physical damage ?

[beardog03]

Not really...not swollen like they were going to blow the splits apart..

The one on the top board has oozed about the size of a quarter or so..

The others are on the tops and some top and bottom..

I will get some better pic`s , as I just got home with the new one, and I`m done hooking her up to her new home !!

I got a fair deal, not stellar, but fair...
I was able totalk him down a couple of Franklins


Less than 50 hrs he says....looks like it too..!!

[beardog03]

man This thing is BRAND NEW!!! :D :cool:

I just thought of something...

don`t laugh, but because of lack of rack, I have the amp sitting on the PB10 sub....didn`t realize the vibration was so bad until I turned the new amp on and it started rattling....
:rolleyes:


okay
Flame away....!!!

[GV#27]

flame away....!!!Nah I don't think we need anymore flaming on this board for a while.:D

[beardog03]

cool

I have had one of those days today anyway....

[billbillw]

beardog,
I suspect that you are seeing the epoxy/glue on those caps. My PLD-2000 has this stuff all over the board, but the caps are just fine.

However, my HCA-2200 did have a few leakers in the powersupply section. The difference is that if they are leaked electrolyte, the residue will be somewhat crystalline, not glue-like. It will chip away easily like dried salt. The glue won't do that. Also, if that many caps were bad from leaking, your amp would have developed a terrible hum due to lack of filtering. Also, those little caps probably wouldn't cause the amp to go into protection mode, it would just sound terrible.

Edit: I'm not saying that wouldn't be beneficial to replace all those caps, but it may not be the actual problem with the amp going into protection mode. Given the value of that amp, I would pay to have a technician look at it and do it right. Heck, since you are in the Bay Area, it might be possible to take it straight to Parasound and have them fix it.

[shadowofnight]

No leaky caps...all glue...I went to Bears place last night. One out of the 5 temperature monitors ( Encapsulated thermistors ) was showing high ohms and causing the front panel fault......the contacts to the board had oxidized ...pulled cleaned all good...amp powered right up in its normal state no indicated problems( Cleaned and tighted all of them while we were in there ...zero temp fault indicators now ) . Bear grabbed some test gear to hook up and we fired it up...checked all 5 channels for output...all were fine...except for one really annoying problem....somtimes one of the 5 relays UNDER the control board would not click stating its associated amp was stable and ready to use.

So we tested the hell out of it...probably over a hundred duty cycles ..and once in a while that relay would not audibly click ( We didnt pull the control board ) and the amp would not ready ( But still no fault indicators on the front panel...all 5 channels would still be green as well as the power indicators would still show normal. ) It was too late to pull the control board and check/swap relays. It's now just an irritating intermittent relay under the control board...with schematics it should be a piece of cake for Bear. ( We both did a bit of overzealous power cycles and blew the fuse on the channel 3 amp :) one time )

[shadowofnight]

beardog,
I suspect that you are seeing the epoxy/glue on those caps. My PLD-2000 has this stuff all over the board, but the caps are just fine.

There wasnt one bit of electrolyte anywhere in that sucker...but the glue applicator should have been shot :) It was in places it wasnt meant to be...just glue drips ...not one bulge...no leaks. As soon as I looked at the temp sensors and saw the same brown glue holding the screws and all over the heatsink away from components ( Sloppy :) ) Besides, it was hard as a rock and not that nasty pastey like salt electrolyte crap. Even though it was easy to determine AT the unit...that was a good call by just seeing the pics Bill :D

[billbillw]

Even though it was easy to determine AT the unit...that was a good call by just seeing the pics Bill :D

I was only able to say that because I saw the same thing on my PLD-2000. Sounds like Beardog is well on his way to having the amp in working order.

[GV#27]

...that was a good call by just seeing the pics Bill :D I alluded to that very possibility in post #35;)

Good see your amp is OK bear.:)

[beardog03]

you guy`s were right....no leaky !!

thanks for all your help last night Shadow....I had a blast tinkering with the amp...

I`ll get her up and running soon enough

The "replacement" amp is really working well ...!!