Gallien-Krueger 800RB board layout

[Jon Snell]

I have a GK 800rb in for service. There was a catastrophic failure and the board has no printed idents left due to the black soot etc.


The board damage is not an issue, the question is ... component identity.
Has anyone got a layout of the main PCB drawing or maybe a detailed photograph I can work from please?

It would certainly make life easier for me otherwise a few hours will be spent on educated guesswork.
Thank you for looking.

[Pedro Vecino]

I have found this. Maybe it can be useful.

[Intripped]

another thread on this forum with a similar damage and schematic reference:
https://music-electronics-forum.com/...k-800rb-repair



PS: and here Nevetslab posted a pdf with a Parts Placement guide:
https://music-electronics-forum.com/...664#post783664

[Jon Snell]

Thanks for that, I may be able to use the photo of the burnt board. I already have the service manual but unfortunately it doesn't show the main PCB.
Best regards.

[Intripped]

please get a better look at the pdf posted by Nevetslab. it's not the service manual

[Jon Snell]

All I get is 'Invalid File Specification" and cannot download anything from 800RB_SM2.pdf

[Pedro Vecino]

Could this be?

[Jon Snell]

Could this be?

Thank you.
I can prepare the board now.
Best regards.

[Intripped]

...in theory the link in my post should bring you directly to post #50 of the other thread. There's the pdf I was talking about (by the way, it is just the first page of the pdf that Pedro Vecino provided).
Anyway, problem solved, that's the important thing.
Cheers

[Jon Snell]

...in theory the link in my post should bring you directly to post #50 of the other thread. There's the pdf I was talking about (by the way, it is just the first page of the pdf that Pedro Vecino provided).
Anyway, problem solved, that's the important thing.
Cheers

I should be able to work out where the tracks used to go and hard wire them before varnishing unless there is a layout of the underside of course.

[nevetslab]

Could this be?

That was it. I had relabeled that file as 800RB_PwrAmp_PCB_Parts Placement_RevC.pdf below:

800RB_PwrAmp_PCB_Parts Placement_RevC.pdf

I also checked my service files on the 800RB, expecting to find a lot of photos on the various flame-out failures I've had on our rental 800RB amps over the years. For some reason, I don't seem to have taken ANY photos of those. So, nothing to share in that area this time.

Dave M's contribution in the 1st MEF link addressed that typical problem, highlighting the circled components in the output stage, and a good photo of the damage.

[Intripped]

looking at this schematic





IMO this is how it should be (in green)

[The Dude]

Apologies if it's already been posted, but I have this document which shows layout and a parts list (towards the end) to help identify burnt parts.