Fixing Xenon amps

[KyferEz]

Is there anyone here who's willing to assist in fixing PG Xenon amps?

I've begun repairing amps (successfully repaired all 4 I've attempted thus far, but none are a PG). After looking at these Xenon amps, I realized they are a bit more complicated than the ones I've been working on (Orion, Earthquake, Memphis, Kicker)

I've got to get started somewhere, because I got a bunch of these broken real cheap. Here's what I got:
X600.1 - I have 2
x200.2 - I have 2
X1200.1 - I have 3
X200.4 - I have 2

No, I'm not looking to sell them; I want to fix them for my own use (Likely all in the same vehicle LOL). It's going to be insane, and I'm targeting accurately reproducing the full audio spectrum, not just the bass, at high SPL, and that's all I'm saying about that - for now.

Anyway, typically I look for physical damage, then test for shorted FETs/darlingtons, but in this case, nothing is shorted and nothing is smoked in any of the amps. Plus, since there's so much extra circuitry on this board, I'm a little hesitant to start probing around with the oscilloscope to test the supply.

So I'm starting with the X200.2, cause it's the least of a loss if I accidently destroy it. I powered it up with a 2Amp limited supply (which will power up nearly all amps at idle) and one internal Red LED comes on, as well as the blue power led comes on constant (no blinking). The fan powers up full speed then slows down.

Any suggestions?

P.S. No, I don't want to send them in to anyone to be fixed - I want to learn to fix them so I can do it if and when they blow next time.

[Mastiff]

nope not touching this one ......G/K

[1moreamp]

nope not touching this one ......G/K

Me neither

[Mastiff]

oh come Cecil he could be your padawon...

[KyferEz]

Obviously I'm missing something... What's up guys?

I'm not a newbie when it comes to electronics - just to amp repair. My forte is designing electronics systems such as digital controls with microcontrollers, not repairing stuff others design and build, though I've been learning.

Note: those amps came from a PG warehouse that closed down. Most have not been worked on. The one that has I'm not touching until I fix the others, and it's one of the X600.1.

KyferEz

[VW337]

If the main LED come on Blue and is lit solid the amp should be functional, the internal RED LED means nothing.

[Bfowler]

Obviously I'm missing something... What's up guys?

I'm not a newbie when it comes to electronics - just to amp repair. My forte is designing electronics systems such as digital controls with microcontrollers, not repairing stuff others design and build, though I've been learning.

Note: those amps came from a PG warehouse that closed down. Most have not been worked on. The one that has I'm not touching until I fix the others, and it's one of the X600.1.

KyferEz

so that leaves me to believe your a local?

[stipud]

I believe the most common flaw with Xenons was dry solder joints. After getting a bunch of defects in the first batch, PG started resoldering everything in house. After that, the reliability became ridiculously good... so the only problems you should see in that case would be pretty obvious (i.e. burnt transistors, etc).

[1moreamp]

Note: those amps came from a PG warehouse that closed down. Most have not been worked on. The one that has I'm not touching until I fix the others, and it's one of the X600.1.

KyferEz

And here lies the issue, since these were not worked on then they represent a bag full of surprises, and possibly may not be repairable by normal reasonable means.

Your background is in digital electronics, correct? Then your not use to analogue design and this makes your learning experience a up hill event.

Electronics being divided into Analogue and Digital does not help. I take it by your statement you possess a EE in Digital electronics, would this be a correct assumption ?

Well there isn't much digital in any of these amps except for the clock base circuits for the class D amps, the rest is all analogue. I respect the fact that your enthusiasm has you inclined to master these amps but without schematics your battling up hill. And PG does not release documents, so you are SOL here.

I work on Zenon's for my self, and for others for a living. I actually work on all brands of amplifier thats sorta why I don't envy your position. Except for the clones coming form Korea and China all the other amps out there are basically derived from a Op-amp design only larger in scale. thats as simple as it gets. From there on out you will see the differences in engineer's and engineering, and of course manufacturing.

[KyferEz]

so that leaves me to believe your a local?

Nope, bought them off some guy who was a local. I'm nowhere near PG.

And here lies the issue, since these were not worked on then they represent a bag full of surprises, and possibly may not be repairable by normal reasonable means.

Your background is in digital electronics, correct? Then your not use to analogue design and this makes your learning experience a up hill event.

Electronics being divided into Analogue and Digital does not help. I take it by your statement you possess a EE in Digital electronics, would this be a correct assumption ?

Well there isn't much digital in any of these amps except for the clock base circuits for the class D amps, the rest is all analogue. I respect the fact that your enthusiasm has you inclined to master these amps but without schematics your battling up hill. And PG does not release documents, so you are SOL here.

I work on Zenon's for my self, and for others for a living. I actually work on all brands of amplifier thats sorta why I don't envy your position. Except for the clones coming form Korea and China all the other amps out there are basically derived from a Op-amp design only larger in scale. thats as simple as it gets. From there on out you will see the differences in engineer's and engineering, and of course manufacturing.

Yes, I have an EE. There's no such thing as an EE in Digital, it's just that where I have worked during and after college has been primarily focused on digital designs. There is always some analog in with the digital designs, but not that much and these are designs I am doing or worked extensively with, and thus I know the entire project inside and out whereas with these amplifiers, there is, as you say, very little digital and no schematics to be had. THIS is why I have asked for help from someone who knows about them: Give out a few pointers, and answer a few questions.

The other amps I've repaired was without schematics. Of those 4, three were easy, one was slightly more difficult, but none were extremely difficult. Mostly the supply FETs had burned up, or the output transistors went bad. The one that was a little more difficult was a Class D that had bad supply FETs and also had bad buffer transistors between the TL494 and the supply FETs. It then had a bad HIP4080 and 2 bad output FETs. Nothing a little testing with the proper tools couldn't figure out. The most trouble I had was finding substitutes for the Korean parts or parts that were discontinued, but now I have sources for finding most any of those...

So far, amplifier repair has been far easier than I imagined; definitely far easier than some of the digital design work I've undertaken recently. I was just worried that potentially these were far more difficult amps to repair - and thus was hoping for some tips from those in the know. I.e.:
1) What are the top 4 or 5 most common failures on these amps (aside from the ouputs/supply FETs/Transistors failing)
2) any peculiarities I should be aware of with these amps
3) What do the Red LEDs indicate (not mentioned in the manual)?

So... Will I continue to be told it's too hard? If so, don't presume I'm going to give up... I a stubborn SOB that doesn't like to be told no.

If the main LED come on Blue and is lit solid the amp should be functional, the internal RED LED means nothing.

Then what's the purpose of the red leds? In the X200.2 there are 4 - they have to mean something. Two are near the fan connector, and 2 are between the two output channels. Only one of the ones b/t the output channels light up.

KyferEz

[AVICJR]

IIRC the red LED's were/are for QC during assembly for testing.

http://phoenixphorum.com/xenon-faq-vt18 ... ghts+xenon

[KyferEz]

Ha! That one X200.2 is Ok. The guy sent me one that worked! LOL. I went through the other 8 amps, and they def. don't work.

Ok on to the next X200.2. This one's blue LED does blink. It also makes a high pitch AM radio sort of squeal (from the electronics - no input connected and no speaker attached). It's coming from the supply transformer I think. Likely a problem there. I will check that out more later when I get some time. I'm going to be on a crunch for the next two or three weeks with regular work...

The only visible problem is related to the daughter boards on the output. A surface mount cap C100 is missing/damaged on both daughter boards. On one, it looks as if the cap exploded. On the other it split in two. Seems an odd part to be damaged... Fortunately I can take the other X200.2 and get the value of the caps off it by removing one and testing it. One other part may also be damaged on the daughter board, Q113, a Fairchild 208 339S, which looks to be a dual-ch optocoupler.

Other than that, the amp is pulling excessive current at idle with no input. I'm betting it has to do with the supply, based on the noise it's emitting. It's still mounted to the heatsink, and still on a 2amp limited supply, so nothing's getting noticeably hot. I'll disassemble it and find out.

What conditions, specifically, can cause the blue LED to blink?

Thanks,
KyferEz

[1moreamp]

EE's specialize nowadays, so my reference to EE in Digital should have been phrased EE specializing in Digital. Sorry about that Please forgive my poor selection of grammar I meant no rudeness.

[1moreamp]

IIRC the red LED's were/are for QC during assembly for testing.

http://phoenixphorum.com/xenon-faq-vt18 ... ghts+xenon

Those LEDs tie into several different sections of the power supply, and are basic go no go indicators for Over-temp, turn-on, and safety. At least that’s what my notes say I made on my 200.4's
If you will look back at the very first amps PG ever made you up till the Xenon line you will see three LED's on the amp. One is for Over-temp, one is for Overload, and one is for normal ops power supply latch on. <Green>

PG has not changed much over the years and those same basic ideas from the very first MS amp up to the Xenon are still in play. Why change a good thing. Now the xenon uses all red LED's so I am sure I understand why one would be confused. You must reverse engineer the circuit of the LED that is lite up and see if there is an issue.

[KyferEz]

I apologize too. I should have stepped back and waited before making that post. It seemed I was being talked down to; had I taken a moment longer to think, it was obvious that wasn't what you intended at all. Sorry to you and everyone else reading.

I guess everyone has learned I'm also a bit of an impulsive SOB too

KyferEz

[Mastiff]

]

[1moreamp]

1) What are the top 4 or 5 most common failures on these amps (aside from the ouputs/supply FETs/Transistors failing)
2) any peculiarities I should be aware of with these amps

KyferEz

I don't work for PG so I have no detailed product profiles of failure. And I am sure that it is a state secret at PG. It would be if PG was my company. So I seriously doubt if those sort of files and info are available to anyone except certain PG engineers and management.. Sorry

There was a bad batch of amps, an early run from overseas. I sincerely hope you have not stumbled onto a part of those that were never caught and taken care of by PG. Only a serial number check will tell. If I were you I would call PG and ask for a serial number check of all your amps. They have detailed files and they have shared this info before without issue. < Just a suggestion>

Hope some of this has been helpful, there isn't much more available. I think you might be better armed for your task if you go to the PG site and search the product manuals for more info as to basic spec's and such that they have posted. I probably can quote you some of it but the files are free to download for your reference in PDF file format. This info will brace you for your task with at least some of the basic tech info specs.


Oh heres a couple good links for some info:

ftp://207.109.65.132/Phoenix_Gold/Manua ... iers/XENON

http://www.phoenixgold.com/2004/flatrate.html

[KyferEz]

I don't work for PG so I have no detailed product profiles of failure. And I am sure that it is a state secret at PG. It would be if PG was my company. So I seriously doubt if those sort of files and info are available to anyone except certain PG engineers and management.. Sorry

I figured there would be a few things that you guys would have noticed while working on them that tend to fail, aside from the primary outputs, primary supply fets, and power resistors. If not, then great! Means they may be easier to fix than I initially thought.

There was a bad batch of amps, an early run from overseas. I sincerely hope you have not stumbled onto a part of those that were never caught and taken care of by PG. Only a serial number check will tell. If I were you I would call PG and ask for a serial number check of all your amps. They have detailed files and they have shared this info before without issue. < Just a suggestion>

I will give that a try, thx for the suggestion.

Hope some of this has been helpful, there isn't much more available. I think you might be better armed for your task if you go to the PG site and search the product manuals for more info as to basic spec's and such that they have posted. I probably can quote you some of it but the files are free to download for your reference in PDF file format. This info will brace you for your task with at least some of the basic tech info specs.

That was the first thing I did

Thanks. I'll keep posting here as I work on them, if noone minds. Maybe it will help someone else in the future.

KyferEz

[BH]

Sure there is such a thing as EE in digital... I have a degree in it.. Its called Computer Hardware Engineering Technology. Then for grins I also got the Computer Software Engineering Technology one too.

so that leaves me to believe your a local?

Nope, bought them off some guy who was a local. I'm nowhere near PG.

And here lies the issue, since these were not worked on then they represent a bag full of surprises, and possibly may not be repairable by normal reasonable means.

Your background is in digital electronics, correct? Then your not use to analogue design and this makes your learning experience a up hill event.

Electronics being divided into Analogue and Digital does not help. I take it by your statement you possess a EE in Digital electronics, would this be a correct assumption ?

Well there isn't much digital in any of these amps except for the clock base circuits for the class D amps, the rest is all analogue. I respect the fact that your enthusiasm has you inclined to master these amps but without schematics your battling up hill. And PG does not release documents, so you are SOL here.

I work on Zenon's for my self, and for others for a living. I actually work on all brands of amplifier thats sorta why I don't envy your position. Except for the clones coming form Korea and China all the other amps out there are basically derived from a Op-amp design only larger in scale. thats as simple as it gets. From there on out you will see the differences in engineer's and engineering, and of course manufacturing.

Yes, I have an EE. There's no such thing as an EE in Digital, it's just that where I have worked during and after college has been primarily focused on digital designs. There is always some analog in with the digital designs, but not that much and these are designs I am doing or worked extensively with, and thus I know the entire project inside and out whereas with these amplifiers, there is, as you say, very little digital and no schematics to be had. THIS is why I have asked for help from someone who knows about them: Give out a few pointers, and answer a few questions.

The other amps I've repaired was without schematics. Of those 4, three were easy, one was slightly more difficult, but none were extremely difficult. Mostly the supply FETs had burned up, or the output transistors went bad. The one that was a little more difficult was a Class D that had bad supply FETs and also had bad buffer transistors between the TL494 and the supply FETs. It then had a bad HIP4080 and 2 bad output FETs. Nothing a little testing with the proper tools couldn't figure out. The most trouble I had was finding substitutes for the Korean parts or parts that were discontinued, but now I have sources for finding most any of those...

So far, amplifier repair has been far easier than I imagined; definitely far easier than some of the digital design work I've undertaken recently. I was just worried that potentially these were far more difficult amps to repair - and thus was hoping for some tips from those in the know. I.e.:
1) What are the top 4 or 5 most common failures on these amps (aside from the ouputs/supply FETs/Transistors failing)
2) any peculiarities I should be aware of with these amps
3) What do the Red LEDs indicate (not mentioned in the manual)?

So... Will I continue to be told it's too hard? If so, don't presume I'm going to give up... I a stubborn SOB that doesn't like to be told no.

If the main LED come on Blue and is lit solid the amp should be functional, the internal RED LED means nothing.

Then what's the purpose of the red leds? In the X200.2 there are 4 - they have to mean something. Two are near the fan connector, and 2 are between the two output channels. Only one of the ones b/t the output channels light up.

KyferEz

[Mastiff]

omg the nerd is back

[BH]

The guy that did those amps often likes to use LED's just as a voltage drop diode. He does it all the time and honestly often a lot of his led's REALLY do mean almost nothing. Sometimes even the ones that mean something just BARELY come on (and thats what they're supposed to do).

IIRC the red LED's were/are for QC during assembly for testing.

http://phoenixphorum.com/xenon-faq-vt18 ... ghts+xenon

Those LEDs tie into several different sections of the power supply, and are basic go no go indicators for Over-temp, turn-on, and safety. At least that’s what my notes say I made on my 200.4's
If you will look back at the very first amps PG ever made you up till the Xenon line you will see three LED's on the amp. One is for Over-temp, one is for Overload, and one is for normal ops power supply latch on. <Green>

PG has not changed much over the years and those same basic ideas from the very first MS amp up to the Xenon are still in play. Why change a good thing. Now the xenon uses all red LED's so I am sure I understand why one would be confused. You must reverse engineer the circuit of the LED that is lite up and see if there is an issue.

[KyferEz]

@BH - That seems as if it's more like a EET in digital, but touche. I planned to double major too, but full time school & work plus kids & everything else; I was glad it was finally over and I had kept a high GPA.

About the LEDs: After some reading and some posts here, I gathered most of what you said. It's both a little odd and smart to use LEDs as v.drops.

I've had very little time to work on any of these amps, but the 2nd 200.2 looks to have an Ok supply. Aside from what I posted above about the caps on the driver boards, I haven't dug deeper to find any other issues, though I'm willing to bet that some transistors on both driver boards are bad...

I'll have more time in a few weeks to get into this amp. Work has been killer: I've been going nearly 24/7 for the past 2 weeks. 12:30am here and back to work for me; I'll sleep if I finish what I'm working on before morning