Crown XLS 602 2-Channel Amplifier - Answered Questions & Fixed issues

Question edited for a lot more clarity. Question moved from Cars and Trucks Category. Take it in for professional repair unless you have the test equipment. https://www.google.com/search?q=Crown+XLS+2502+drive+core+repairs ...

- Use your favourite search engine (Webcrawler is dandy) and type your question/info into it. - SEARCH ENGINES ARE YOUR FRIEND!!! Type in keywords and check the results. - I'm not an expert but it almost sounds like maybe a speaker relay or whatever on the amp has bailed out. Good Luck :) R

Got the same problem on my amp right now. Trough the schematics i could see that transistors bc184l & bc214l could be the cause in my case. If i turn it on, it can be ok for hours. Untill i turn up the knob with a speaker connected, in 30 sec it shuts down. The PTC on the rectifier board gets hot and also R21&R23 a bit. I will try to change the 3 pnp/npn and also tip50G. I'll tell you how it will be... One Love Cesare

There are two similar circuits , use the good channel as a guide in troubleshooting.

Hi Tom,The fuse you may be referring from the power supply is not used(none) instead a CB1 or circuit breaker is installed.These breaker is in series with the power transformer ( trace it).Disconnect the AC outputs of the power transformer when trying toreset.( of course with the unit unplugged ).Measure the output AC voltages, if it is OK Be happy partially!Next would be.....Check for possible shorts on the Positive and Negative Supplyrails to ground or speaker out, for what might have caused the breaker to tripped.And these wont be easy troubleshooting , Good luck!!thanks for choosing Fixya for assistance.

Radio shack

Check your input or output cables might be dirty I had the same problemand 1 of my output wire was dirty so i sprayed tha electric cleaner and its all good nowAloha

you are riight there exist several amps like that they having different frequency on each side i supose its not properly made like that or better they wanted a pasty sound on one side and a thin on the other many times it happened to me - in older days specially lots of european amps the solution is a equalizer on the front and equilze it smoth how u want it

hi,
First of all you have to check The positive and negative 95V in the collector pin of all output tansistors. There should be +95V in the all collectors of MJ15024 and --95V in all collectors of MJ15025 poer the output transistors of faulty channel.ANd tere should be +/-- 0.5 volt in all output transistors base pin. All emitter pin should be aproximatly 0V. If not then you have to check the tansistors Q13 to Q16 and Q17 to Q20. Also the driver transistors Q9, Q10, Q11,Q12,.
If you need the schematic diagram that i will sent it to you.
ok

It is capable of detecting cooling fan failure so I would presume it hasn't decided to engage the fans yet.

It sounds like a thermal issue. Is it in fact getting hot? There are fans. Are they working when hot?

Hi,
When you heared or noticed any burnout components,most probably from the regulators/rectifiers/IC's/ voltage limiting dides/ etc,it means you're having a problem on your driver up main outputsection in your circuits ,you have to check steps by step,n most cases,like this HIGH POWER AMPLIFEIRs,its using a high wattage transistor/Mosfet particularly,
After replacing some faulty components,,Please,.kindly .do not connect immediately your expenssive speaker's,if you've 8ohms /50-100W dummyload parallel with your( ohmmeter on AC set), to monitor the ac abrupt dumping factor on the main output,
CAUTION;
When you noticed your amplifier is having a problem like poping sound/motorboating sounds/burned components and smell/trembling with low freq sound and etc,
Do not connect your speaker,specially HIGH POWERED OUTDOOR AMPLIFIERS just to avoid any damage or create fire, and extend some components damage on the circuits,
OPTIONS:
In deep repairing and troubleshooting in any electronic equipments, it needs complete diagnostic tools/schematics/techniques,...experience and observation sometimes is required,
IF YOU DONT HAVE IT,ITS BETTER TO BRING YOUR AMPLIFIER IN A SERVICE SHOP,
My friend,thanks and good luck,.

They use a breaker instead of a fuse.

http://www.retrevo.com/support/Crown-XLS-602-Amps-manual/id/19050ci763/t/2/

CONDITION: No

power to the amplifier.

POSSIBLE REASON:

• The amplifier's Power switch is off.

• The amplifier is not plugged into the power receptacle.

• The amplifier's high-voltage power supply circuit breaker has tripped. Verify that the AC mains

voltage is correct, then press the Circuit Breaker button on the back panel.

Take it to the ER.

Common problem. Power transistor in channel#2 is weak or out completely.
Bridging converts from 2 channel(stereo) to mono and you are are useing both channels in series to effectivley double your output.

From what I know about these and after checking the schema , I would say that a thermal fuse in the main AC transformer is open.
If this helps, please rate my help
Thanks, Scott

I would not recomend disconnecting the fans. They might be running to keep a certain heat sensitive (and perhaps expensive) part cool. However it could be the case that the fan speed control circuit has developed a fault, therefore the fans are running too fast.

Potentiometers don't really have a brand as such. To replace one you go on ohm range (most often marked on it). The next thing is size and getting it to fit.
You can look around any parts shop once you know it's value in ohms.
One thing I can tell you if you can hold of the service manual it will give you the ohm value and quite possibly a part number. This could help you track down the exact part. Two more things! I believe that Crown are connected with Hitachi. Also from an old spares guide that KEY ELECTRONICS deals with Crown parts. I couldn't tell you if Key still operates though.

Hi...

There may be some internal fuses on that unit.

You can open it by taking the cover off and looking for fuses and discolored parts.

It may have a thermal fuse on the power transformer which then will require service

Check the web for service people in the UK

Lots of electronics have lights (LEDs) that turn on when they are plugged it. Most people just don't notice them. If it is working properly, then the light is normal.

Every time i have this prob i've blown that channel. In my case i,ve had dodgy connections to my speakers and if it is operating with high voltage rails they don't take much to blow.
Take off cover and you will no doubt find fuses somewhere blown. If it has come from speakers you prob done the amp but if not you might be lucky and just have to replace a single fuse or so.Good luck,Paul