Crown CTS4200 SMPS

[Jazz P Bass]

I received a 5 year old Crown CTS4200.
"shoots sparks"
SMPS took a dump.
IGBT's are blown.
Controller IC is toast along with the SMT transistors that it drives.
No biggy, right?
Hah!
The controller IC is on a standup board.
Cool! The parts that are going to fry are on one board.
Swap it out, replace the IGBT's, fix the secondary + - 15 volt power supply ( filter caps popped).
Wrong!
The little standup board has no part number. It is NOT available.
The one that is in the amp got a "little" hot & fried the traces.
Call Crown back, "Oh, you have to replace the main board"
$564.12
A $150 repair just escalated to $700.00.
Crown uses the snap-off method of circuit board manufacture.
All the ancillary boards snap off at assembly.
So if they rob a standup board for a repair they are left with an unusable assembly.
How hard could it be to outsource the standup board?
Or reprogram the pick & place robot to only stuff that little board.

[Techknowman]

SMT stuff is fun.
Especially if you don't have hot air rework tools.
But i know what you mean, its almost like they don't want it even repairable.
Its no wonder landfills and "filling up" with junk electronics.

[J M Fahey]

Don't they furnish the schematic?
*Maybe* you can "downgrade" the design and replace the f*****g SMPS with an old fashioned, robust Toroid.
Even if the full size one does not fit into the chassis, maybe you can still fit a smaller one and still have a usable amplifier.
As a personal choice, between a landfill piece of steel and ,say, a working 500W amp downgraded to 200W , I would take the second one any day of the week.
I "repaired" SMPS powered Gallien Kruegers 150W units with my own very conventional EI iron 100W transformers.
The clients? Happy !!!
Opinion on "just throw it away" company policy?:
unprintable.
Ask for the schematic and post it.
Good luck.

[Jazz P Bass]

Crown controller board

Yeah, I even thought of firing up my Protel circuit board software & duplicating the board.
Drill charge & engineering charges will run around $150.00.
Maybe even sell them to Crown!
I purchased the new main board for the customer, so now the amp is missing the chassis & cover, the ****controller board, the secondary +15 -15 +5Vdc power supply (another SMPS) & the fan.
I got (16) "graded" MJ21194's out of the deal.
Will gladly part out the amp if anyone is in need.

[J M Fahey]

Maybe even sell them to Crown!

Maybe not to Crown themselves (you will hardly match the U$6 their Chinese supplier charges them) but certainly you could sell a few to other technicians through EBay.
Even more useful , I think the product might be a generic "one size fits all" board, which gets the standard rectified 300V and drives the original transformer, which almost always is still alive.
I'm thinking about making that myself, both for personal use and to sell in Argentina and surrounding Countries.
Ah!! Thanks for posting.

[MarkusBass]

Jazz,

Can you post a photo of the small board? How bad are the traces fried? It often happens that only 1 or 2 traces need to be fixed. But as Techknowman said, you need hot air rework tools to fix it. And some practice with SMD stuff is also required.

Mark