Crown XTi 6000 Problem
Posted 17 October 2013 - 10:01 AM
I have a 2 Crown Xti6000 amplifiers, one works great, the other has an issue which I need to address and repair.
About a week ago I was using the XTi6000 at an event, I noticed that the Thermal Light was illuminated on channel 2, the speaker in channel 2 was still working fine, however the amps fan was on full speed! I remember reading somewhere that if I held the 3 buttons on the front of the display it would show the temperature of each channel...Channel 1 was 37 degrees and channel 2 was 87 degrees...same speaker on each channel, same input.
I tried to self diagnose the problem, doing process of elimination, here is what I did;
1) Maybe the speaker cable is bad? Bought new cables, didnt work
2) The amp is wired to a "patch bay" in the front of the amp, which has 2 XLR inputs (feeding the crossover) then 2 speakons (which run through banana into the amp) I thought maybe somewhere between there might have been a crossed wire or something....so I eliminated that and went direct....Didnt make a difference.
3) Maybe there is too much in the rack and its over heating, I took it out of the rack and on my coffee table......
I turned the amp on, nothing plugged in but the power cable, let it idle. (fan set to come on when it hits 35?) did a few things around the house and not 15 minutes later the fan had kicked on at full speed, i checked the channel temperatured, Channel 1: 33 degrees, Channel 2: 82 degrees..........nothing feeding the amp a signal or speakers plugged in, nothing!!!
I really need to know what is wrong and how to fix it asap as I use the 6000's to run my subwoofers, they are extremely important.
Any help would be appreciated.
Posted 17 October 2013 - 11:56 AM
The problem you're describing is not due to an external issue but rather an internal problem. May I ask if you are an electronically oriented person? If not then a trip to the close Crown service center is most advisable.
Posted 17 October 2013 - 06:05 PM
I am electronically orientated, if it's over my head I have someone close who is. What do you think the fix to the problem is?
Posted 17 October 2013 - 11:39 PM
Posted 18 October 2013 - 08:08 AM
Verify if the heatsinks are not clogged! That would cause a lot of grief! I still suspect something else.
Primo: I'm suspecting the thermal distress is caused by a misjudgement of the output devices temperature control sensors. Measure the thermal sensors first.
To evaluate and measure the output thermal sensors: Power down if unit is operating; Remove the top cover; Identify the temperature sensors in the output section (device is located under the HS (High Side) forked clamp; You will need to remove the BCA coils and isolator to access the clamps' view); Identify the Front End cards (vertical card with small visible pot on top) and remove them; Identify the sensor's connector and measure sensor's resistance: should be about 20K without FE boards or 7K with the boards in (note: measurement should be done without the FE cards installed); If the measurement is off, then replace the sensor. Both sensors should be about the same.
Secundo: If the sensors appear appear good:
XTi6000 is a BCA amplifier [not an analog amplifier!]. I suspect that the output section is in need of a good refurbishing: removal and cleaning of the heatsinks (4x), cleaning of the output devices (24x), reapplication of thermal compound on the output devices and heatsink, reform (if needed!) the forked clamps, replacement and installation of the t-sens foam (2x) on the HS clamp, evaluate and adjust the ULOL (UnderLap/OverLap) adjustment.
Note: Output devices can explode if not cooled enough!
Posted 28 October 2013 - 10:32 PM
Thanks for your detailed reply!
how much are the heat sensors and how do I go about getting one?
Posted 05 November 2013 - 05:03 PM
Are you an experienced service technician? If not, I would highly recommend that you get in touch with the authorized Crown service center.
Else, you have to determine if the <thermal> fault you're getting is a failed component or perhaps, just a refurbishment would be necessary.
I would at least start with the refurbishment : Remove the BCA module, remove the BCA coils, remove the forked clamps;
Once you have the output componets off the heatsinks, clean the compound off the output devices and heatsinks; Reapply a coat of thermal paste to both sides (components and heatsinks); Reinstall the heatsinks and clamps. Make sure that the output devices are well clamped down and that the devices don't move under the clamp. If the output device is not clamped down enough, there is a possibility of serious damage! (see a qualified Crown technician). Check the t-sens foam: it should still be maleable and not hard as a rock!