Xenon problems…

Post by **Eric D** » Tue Apr 28, 2009 10:42 am

I have a X200.2 which works fine but the fan is on full speed all the time. Has anyone had this happen to them, or does anyone have a clue what is going on with it?

The amp is not drawing an abnormal amount of current, and it sounds great. LED4 is lit, none of the others are.

I am getting really frustrated with Xenon amps. This one had a bad channel and after hours of work I found this trace burnt under this transistor in the attached photo. Finding something like this a royal pain in the ass. After fixing this I would guess this is not related to the fan staying on but I don't know for sure.

Post by **stipud** » Tue Apr 28, 2009 10:49 am

Wow that is a ridiculous spot to have a trace burn out.

What is that daughter card used for?

Post by **Eric D** » Tue Apr 28, 2009 10:52 am

I guess I would call it a voltage gain stage for one of the channels. There are two of these cards, both have bias control pots on them, and they directly feed the main output transistors.

I suppose you could also say these contain the first two stages of "Triple Darlington".

Post by **stipud** » Tue Apr 28, 2009 11:03 am

Not sure how I feel about part of the output stage being mounted to daughter boards. I guess soldered in like that, they should pose fewer issues. And on the plus side, they could be completely replaced very quickly. Then again it's normally the big output transistors, and their emitter resistors that get the brunt of the damage. So I can't see the need to replace those primary stage boards all too often.

On the other hand the daughter boards for the crossovers and caps in the ZX line made more sense to me. With the pots oxidizing over time, and the caps failing, PG could swap those daughter boards relatively quickly and have the amp fixed quicker than with conventional mounting. The cost of the daughter boards is probably negated by the time saved by the repair techs.

I always thought Xenons were too big for the power they gave you. Now that I know the two first output stages are mounted to daughter cards as well, it makes me wonder where all the other real estate is being used. Xe.load? I wonder... Maybe I should pick up a busted Xenon to familiarize myself with.

Post by **Eric D** » Tue Apr 28, 2009 11:20 am

In the case of this amp, I think the daughter boards are required, as there really is no space on the board. The amp is pretty densely packed with parts. It is also significantly overbuilt.

These cards are soldered in. To pull one out you need to take all the screws out of the amp, all the clamps off the main transistors, then pull the main board off. Then you have to desolder this card which has two separate rows of connections. This is a very lengthy process and not something PG would do quickly. Now if they made these plug in that would be great as you could work on one without taking anything else apart.

dBincognito · Post by **dBincognito** » Tue Apr 28, 2009 11:22 am

In regards to the fan, is it OEM ?

Post by **Eric D** » Tue Apr 28, 2009 11:24 am

dBincognito wrote:In regards to the fan, is it OEM ?

Yes

dBincognito · Post by **dBincognito** » Tue Apr 28, 2009 11:26 am

Eric D wrote:
dBincognito wrote:In regards to the fan, is it OEM ?
Yes

Hmmm....Xenon...either great or horrible it seems like...I'm guessing this was from the first run

dBincognito · Post by **dBincognito** » Tue Apr 28, 2009 11:28 am

and damn the print is so big on those boards a blind man could read it

Post by **stipud** » Tue Apr 28, 2009 11:35 am

dBincognito wrote:Hmmm....Xenon...either great or horrible it seems like...I'm guessing this was from the first run

The "first run issue" was cold solder joints. A broken trace doesn't seem to fit this issue. Though it could still be the case if there's cold solder in the fan control circuit somewhere...

Post by **Eric D** » Tue Apr 28, 2009 11:36 am

Here are some additional photos in case anyone wants to point things out with paint or something...

Post by **AVICJR** » Tue Apr 28, 2009 11:56 am

I've owned several Xenons and only 1 bad unit so far, I have noticed that the fan comes on full tilt on some and stay that way for a few but it eventually settles. I have a Xenon that I bought for parts if you want to try switching out the fans.

Post by **Eric D** » Tue Apr 28, 2009 12:01 pm

AVICJR wrote:I've owned several Xenons and only 1 bad unit so far, I have noticed that the fan comes on full tilt on some and stay that way for a few but it eventually settles. I have a Xenon that I bought for parts if you want to try switching out the fans.

Thanks but I took the fan from a working X200.4. I also have a dead X100.4 which is annoying me too.

bogart · Post by **bogart** » Tue Apr 28, 2009 12:26 pm

Ive had two 200.2s die...the one that went to Eric died on my bench after running fine for months....the other was a f/f sale special and gave up the ghost about 93 days after I bought it....of coarse. The only ones that gave me issue were the 200.2s and I just chalked it up to the run.

That 200.4 ran for two years and left me doing the same...never a problem. The fans are wonkie on every xenon I've owned...sometimes a hum or different speeds all the time....I tried putting different fans in and it was always the same old thing...I love the 200.4s....monster amps and they are very clean.

good luck with the xenon endevour Eric

dBincognito · Post by **dBincognito** » Tue Apr 28, 2009 12:29 pm

bogart wrote:Ive had two 200.2s die...the one that went to Eric died on my bench after running fine for months....the other was a f/f sale special and gave up the ghost about 93 days after I bought it....of coarse. The only ones that gave me issue were the 200.2s and I just chalked it up to the run.

That 200.4 ran for two years and left me doing the same...never a problem. The fans are wonkie on every xenon I've owned...sometimes a hum or different speeds all the time....I tried putting different fans in and it was always the same old thing...I love the 200.4s....monster amps and they are very clean.

good luck with the xenon endevour Eric

If you change fans it should not do that.....unless you use a multiple speed fan...like the ZX amps...and those fans suck....you shouldn't have that problem if you use a 1 speed brushless fan

Post by **Eric D** » Tue Apr 28, 2009 12:53 pm

What ZX amp has a multiple speed fan?

dBincognito · Post by **dBincognito** » Tue Apr 28, 2009 1:24 pm

Eric D wrote:What ZX amp has a multiple speed fan?

As far as I know, all of the ZX and Ti amps have 2 speed fans in them and if they do not....then I would be asking why do they switch between 2 different speeds...b/c they certainly do

Post by **Eric D** » Tue Apr 28, 2009 1:29 pm

To my knowledge the small power supply control board changes the speed for the fans by changing the voltage supplied to them.

Post by **stipud** » Tue Apr 28, 2009 1:48 pm

Either that or it's PWM, but I'm sure variable voltage is more common.

dBincognito · Post by **dBincognito** » Tue Apr 28, 2009 1:50 pm

Eric D wrote:To my knowledge the small power supply control board changes the speed for the fans by changing the voltage supplied to them.

Does it change according to internal temp. ?

Post by **Eric D** » Tue Apr 28, 2009 1:54 pm

dBincognito wrote:
Eric D wrote:To my knowledge the small power supply control board changes the speed for the fans by changing the voltage supplied to them.
Does it change according to internal temp. ?

Yes, there are a few temp sensors scattered around the heatsink plates.

Post by **Eric D** » Tue Apr 28, 2009 1:56 pm

I just checked my X200.4, and it has one LED on when running. Its fans are quiet though.

It seems when a Xenon powers on one LED comes on bright, then slowly goes out and another comes on full. This is the same on my working X200.4 as it is on my non working X200.2 and X100.4.

So, I need to figure out what is forcing the fan on full speed all the time.

thedeal7235 · Post by **thedeal7235** » Tue Apr 28, 2009 2:15 pm

it was the zxv2 that had multiple speeds fan, in the zx series, there is a resistor soldered to the motherboard, i wonder if a different resistor value would lend you more of multiple speeds??; i only know this b/c pg sent me 2 fans, w/2 different resistors b/c i have 2 V1 zxs

Post by **Francious70** » Tue Apr 28, 2009 2:41 pm

Am i going to be the first one to theorize that maybe the amp is running hot enough to keep the fan on full speed?

I know ALL Xenon amps (with the fan) have a high startup speed for the fan and after a second of two they're supposed to spool down. Dunno if your fan control module is broke.

Post by **Eric D** » Tue Apr 28, 2009 3:36 pm

Good guess, but this amp is doing it after sitting on a shelf not hooked up for days.

It is possible the thermal sensor is messed up and telling the amp is too hot. I did some checking on it and it "seems" fine.