crest 200 series

saj888 · 5th February 2009, 02:27 AM

Hi,
I have repaired thousands of pro audio over 20 years. Power amps especially. Crown, qsc, crest etc. I presently have 12 Crest pro 200 series amps in the shop. From 5200 to 9200. One circuit board, 90% surface mount, very high voltage switching power supply. The entire amp has to be removed from the chassis. Does anyone in the world know of a systematic troubleshooting method to repair these contraptions?
Presently it seems like I have to randomly test parts like an amateur tech. Or a crazy tech.
Anyone??

tebbi · 17th February 2009, 03:44 PM

hey,
is it a switching power supply?
Try to put a bulb (or two, at a symetric supply) on the power rail to test it.
Its tricky but it works
round about 50Watts are enough.
I repair since 1984,and often it was a good helper to fix some circutry problems.Most of them switching problems in the power supply.
Greeting
Stephan

saj888 · 18th February 2009, 03:08 AM

Are you serious? We are not talking basic troubleshooting here. Im talking about advanced pro audio troubleshooting techniques. I have already installed 3 switchable bulbs on my 10 amp variac, which came with a built in voltmeter and amp meter. Try downloading a QSC plx 3002 schematic from the qsc site. You would have an idea of what im talking about.
Thanks.

tebbi · 20th February 2009, 02:40 AM

Hallo,
I have seen it,and find it looks a littlebit like a Philips schematic.Most of the technicans mean you can build two television with one.
Okay, what is the main problem (defect)of the most of your amps?
You have the advantage to have a schematic.
Or did you think there is a bug inside the concept?
Some circutdesigns (SMD) are working on the temperature limit.There are a lot of measuring points you can use.

5th February 2009, 02:27 AM	#1
saj888 diyAudio Member Join Date: Nov 2007	crest 200 series Hi, I have repaired thousands of pro audio over 20 years. Power amps especially. Crown, qsc, crest etc. I presently have 12 Crest pro 200 series amps in the shop. From 5200 to 9200. One circuit board, 90% surface mount, very high voltage switching power supply. The entire amp has to be removed from the chassis. Does anyone in the world know of a systematic troubleshooting method to repair these contraptions? Presently it seems like I have to randomly test parts like an amateur tech. Or a crazy tech. Anyone??

17th February 2009, 03:44 PM	#2
tebbi diyAudio Member Join Date: Feb 2009	crest hey, is it a switching power supply? Try to put a bulb (or two, at a symetric supply) on the power rail to test it. Its tricky but it works round about 50Watts are enough. I repair since 1984,and often it was a good helper to fix some circutry problems.Most of them switching problems in the power supply. Greeting Stephan

18th February 2009, 03:08 AM	#3
saj888 diyAudio Member Join Date: Nov 2007	Switching power supply amps. Are you serious? We are not talking basic troubleshooting here. Im talking about advanced pro audio troubleshooting techniques. I have already installed 3 switchable bulbs on my 10 amp variac, which came with a built in voltmeter and amp meter. Try downloading a QSC plx 3002 schematic from the qsc site. You would have an idea of what im talking about. Thanks.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
crest 901 series	sakis	Solid State	0	16th July 2009 05:13 PM
Crest 6A Regulated PSU	imix500	Swap Meet	6	10th February 2009 04:36 AM
crest 6001	ouij67	Solid State	0	12th January 2009 02:50 AM
Crest CA-4 schematics - Anyone?	Zero Cool	Solid State	0	14th January 2007 03:01 AM
Crest SK series Amp Transformer for sale on ebay...	imix500	Swap Meet	3	15th January 2006 01:05 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

20th February 2009, 02:40 AM	#4
tebbi diyAudio Member Join Date: Feb 2009	Hallo, I have seen it,and find it looks a littlebit like a Philips schematic.Most of the technicans mean you can build two television with one. Okay, what is the main problem (defect)of the most of your amps? You have the advantage to have a schematic. Or did you think there is a bug inside the concept? Some circutdesigns (SMD) are working on the temperature limit.There are a lot of measuring points you can use.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read