Crate GX-15R Schematic

[jagora]

I will take a closer look and double check although my past experience with imaging and printing have been as follows: If you scan a document with a tabletop scanner, sometime it saves the image as a prn file.

Joe

[jagora]

I tried it again and my software is saving it as a PRN file because my version of adobe is not compatible with the thumb print

[The Dude]

If that is indeed the case, although it seems odd, try this.

1) Open the document on your computer and make it full screen.
2) Hold down "Shift" and then hit "Print Scrn". It will copy whatever is on your desktop to the clipboard.
3) Open a graphics program like Paint, Photoshop, or something like that and start a new document.
4) Paste the clipboard to the new document (Ctrl+V), or right click then paste. You should see the document now as an image file.
5) Print the image out of your graphics program.

[jagora]

O.K. I'll try that but maybe it's getting late so I'll do it tomorrow.

Thanks for all of the great knowledge

Joe

[jagora]

What is the IC chip called? The chip that is mounted on the Crate GX15R circuit board and cooled by a massive heat sink?

Joe

[The Dude]

It's a TDA2030H output IC.

[jagora]

I have been looking for something like that but it seems to be discontinued, at least the TDA2030/A I took apart a small Fender Frontman amp and it has a similar IC chip but it has TDA2050 stamped on it. Could I recycle that one and use it in place of the TDA2030H? I am also wondering what the most practical method of removing the actual circuit board from the Chassis face plate in order to gain access to the opposite side of the board (required to unsolder bits and pieces) Any good ideas would be great because after I get the courage to try and fix this amp, I have even a more difficult task involving a small Marshall MG10 Amp.

Thanks for all of the feedback and suggestions
Joe

[The Dude]

Yes, you can use TDA2050 in place of TDA2030. I don't recall how a GX-15R is assembled, but commonly you remove the knobs and nuts on the pots- probably some screws board to chassis and carefully pull the board away from the faceplate and tip it back. Take pictures first, in case something comes disconnected or you need to disconnect something to get it out. I almost never completely remove a board or unhook anything I don't have to- just what is necessary to get to the bottom side of the part.

[Enzo]

TDA2050 is just a heavier duty version of the TDA2030, it goes right in place of the 2030.

[jagora]

Thank You very much for this advice. Sorry about the extremely late response from last night. The one thing that scares me about these circuit boards is that some of the wires are not meant to be removed at all. Especially on the Marshall power supply. It looks like the wires are connected with some sort of sealant or epoxy. I suspect that the manufacturer does this on purpose to prevent DIY repairs? I really do appreciate the information you are giving me because now I've built my confidence level to 99.9% and am just about ready to do my first repair.


Thanks Again
Joe

[jagora]

Thanks for the boost of hope and confidence.

Good advice on taking pictures while disassembly in progress. I'll try to gain access to the opposite side of the circuit board terminals using your suggestion.

Appreciate All
Joe

[Enzo]

ANything glued inside an amp is to help prevent it shaking around from vibration and breaking off.

[jagora]

O.K. Then if you peel the glue away, will it expose the soldered joint?

Joe

[chkline]

I'm hoping Enzo or The Dude will chime in on this one. I picked up a used GX15 for my 9 yr old son who is getting into guitar (I am tagging along too!). Plugged it in when I got home, and nothing. Pulled out the board, and started checking and ohm'ing everything out. It looks like the power supply is bad, as there is no voltage coming out of it. The switch tests fine, and has voltage going in, but nothing out. From looking at the schematics posted it looks to be a 14V DC transformer. Does anyone know where to find one of these? I've been searching and have found a couple that look like they might work, but want to be certain before spending any money, as this amp looks to be pretty cheap to pick up used, and don't want to spend too much money on it...

Thanks!

[g1]

Transformers are not DC. Set your meter to AC volts to see what is coming out of the transformer.