Crest 8002 Pro Amp power supply schematic needed!

[irish1968]

I am in need of a power supply schematic for a Crest 8002 Professional Amplifier. I have page 1 of 2, but didn't get page 2 of 2, which seems to have the section I need, in order to find out the values of burnt zener diodes. Any help is needed......ASAP!

Thanks in advance!

Will

11-11-09

 

[Enzo]

COntact Crest and ask for it.

 

[irish1968]

I have already sent a request to the Crest tech support. First thing on my list, as usual, contact the company support, then contact others. Support doesn't always give out certain documents, it was obviously discluded from their download for a reason, not sure why, but I didn't have it from thier available download. Some schematics may only be available to authorized technicians. That's why I requested it on here. Thanks anyways!

P.S.: Haven't heard back from support, and I can't wait days for a response.

 

[Enzo]

I always suggest to my guys to CALL on the phone. A call doesn't usually get stuck in the heap of 1000 emails. Fortunately you are not in Ukraine or someplace. Crest is part of the Peavey family and Peavey has always been top of the heap for customer support. SO Crest has always been forthcoming for me.

I have also had success calling them for tech advice on repairs. the service manager was willing to offer advice. If they no longer do that, I would be saddened.

There is so much power available in those supplies, they can really charcoal when they go down.

 

[irish1968]

Thanks Barr for the schematic, same one I have, and as I mantioned, it seems to be missing a page for the power supply. I will try as Enzo mentioned, and call them. I will first make sure I know what parts to verify, then prehaps they can tell me the burnt out parts.

Thanks for your help!

 

[microsim444]

why you need that? i have the 9002

 

[Empee]

Hello irish1968,

Did you ever succeed in your search for the missing pages in the schematics-folder ?

I seem to have the same problem, finding the "page 2 of 2" of the PFC diagram.

Please contact me if you have the file !


Cheers,

Empee

 

[irish1968]

Hi Empee.

No, I have had no luck in getting page 2 of 2. I haven't received any useful help from this site, and gave up! If I do manage to get it after this, I will try to send it to you. I am thankful for what help I did get, even if it was useless and information I already had, and one that was stupid. So far, no help here, but there is still hope! Sorry I couldn't help you with the same problem.

 

[Eva]

I downloaded 8002 schematics PDF from Crest website, and PFC schematics seem to be complete, what I think is missing are the schematics for the full bridge resonant DC-DC converter that follows.

Where are the burned zeners in the circuit? Do you have any idea of what is their purpose? We may not need manufacturer schematics to figure out a suitable value, if you provide us with enough information... 😉

Detailed pictures of zener locations and anything around (both sides of PCB) may also help a lot.

 

[Zero Cool]

I have the missing page 2!! YES! i contacted crest and got the missing pages. I am in the middle of working on a 8002 myself right now. one channel has a bad supply. blew the mosfets and gate resistors, the first bridge rectifier, the inrush limiters and a bunch of other stuff. I have managed to replace all the bad parts i have found thus far but there is still a problem someplace. email me and i can send out the missing pages!


Zc

 

[Zero Cool]

I have made significant p[progress to understanding how these supplies work. they are actually very interesting. Boost controller supplies centered around a UC3855B controller IC with some interesting twist's to how they do PFC.

For anyone that is working one of these after the Mosfets have blown. check all the following items. all mosfets, gate resistors, incoming AC bridge rectifier. and the MIC422 gate drive IC.

The Housekeeping 15V and 13VPFC supply will not come up until the DC after the rectifier hits about 35-40V and if the MIC4422 IC is bad it will be holding the gates of the mosfets at the 13V rail. causing them to be turned full on at power up.


Zc

 

[F1 FAN]

Hi Zero Cool,I was wondering if I could obtain a copy of the schematic from you for the 8002?Someone asked me to take a look at one as it is apparently tripping a 30amp breaker.It's not in my hands yet but I will need some documentation.


Thanks Fred

 

[Zero Cool]

Hi Zero Cool,I was wondering if I could obtain a copy of the schematic from you for the 8002?Someone asked me to take a look at one as it is apparently tripping a 30amp breaker.It's not in my hands yet but I will need some documentation.


Thanks Fred

send me an email so i can send you the schematic.

 

[spindre17]

Here can anyone have the schematic and of many other amplifiers and brands:
Free Diagrams, Schematics and Service Manuals

 

[F1 FAN]

Excellent link spindre17,thanks for posting it.The 8002 was available.

 

[Empee]

yes,
but in the 8002 schematic there is no page 2 of the PFC board...


F1 Fan,
do you have page two or do you need it still ?

 

[F1 FAN]

yes,
but in the 8002 schematic there is no page 2 of the PFC board...


F1 Fan,
do you have page two or do you need it still ?

Thanks empee upon closer inspection it looks like pg2 isn't there.So yes I guess will need it.The amp is not in my posession yet must it looks like a rather complex beast.

 

[Empee]

it IS rather complex !

here's the PFC board, both pages...

 

[F1 FAN]

Thanks a bunch Empee.

 

[irish1968]

Empee,

Thanks for the page 2 of the PFC power board. Any chance you also have page 2 of the Input PC Board, and the Output Module PC Board, for the Crest 8002. I also noticed these missing as well in my schematics.