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Anyone want to make me a few PCB's?

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qsiguy

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Working on a project and need someone to make 10-15 pcb's for it. I have the schematic for it that opens with Eagle. Not sure if that's the same format for other software. If anyone want's the job let me know and I'll email the file for your review.

I have a second schematic with a board design but apparently it's got a bug in the design somewhere. I'm not really sure what the bug is but supposedly the new schematic is ok, just need a board designed from it. I still need a few details from my friend who's feeding me the info on this.

If anyone wants to try and figure out where the "bug" is with the 1st edition board drawing and schematic I can send you those files. I just don't want to get them mixed up if the same person will be making PCB's from the new schematic.

Here's an image of the "good" schematic, I'll send the file to you if you want to give me an estimate for build them.

**broken link removed**

Here's the board drawing that's supposed to have a problem. The new board will need to be pretty much like this only without the problem :)
**broken link removed**
 
justDIY said:
lol... are you serious?

www.custompcb.com

Well, he *did* offer to pay for it. But yeah, I'd also suggest a low-run PCB house like the one you mentioned or ExpressPCB or something--likely to be much cheaper and faster than hiring someone to do it at home. Especially as this looks to be something which will need through-plated vias and some fairly tight tolerances for home-brewers. Or, more accurately, it's not something I'd try to do on my bench, but I've only done a few of my own.

As for the "find the bug in the board" bit, that's not something a board house will do for you (at least, I wouldn't think so). Maybe with some more information the bug will be easier to spot.


Torben
 
lol, yes. Thought maybe there was someone here that was a wiz at fabbing PCB's that would like the job. I'm waiting for word back from the guy that should know a little more detail on the problem issues as well as dimensions for the board and various specs.

Don't really need the board house to fix the problem, supposedly the schematic is fixed, just need it converted into a board. They can use the old board diagram as reference if needed.

Thanks for the advice, I'll check with that "custom PCB" place. Has anyone used this place?
 
qsiguy said:
lol, yes. Thought maybe there was someone here that was a wiz at fabbing PCB's that would like the job. I'm waiting for word back from the guy that should know a little more detail on the problem issues as well as dimensions for the board and various specs.

Don't really need the board house to fix the problem, supposedly the schematic is fixed, just need it converted into a board. They can use the old board diagram as reference if needed.

Thanks for the advice, I'll check with that "custom PCB" place. Has anyone used this place?

Not I--I've never used any PCB house (kinda new to this myself :) ). But I haven't heard of any which will design the board for you, at least not of the short-run places.

The company shown (CustomPCB) doesn't accept schematic files, so I guess they won't design a board. As far as I know, ExpressPCB makes you use their layout software and then send in the files.

Maybe someone else knows of one. Maybe Bill (user blueroomelectronics) knows more about this.


Torben
 
If that is the corrected schematic then you still have a problem Tying the output of a NAND to gnd when both inputs are also gnd is not a good idea. If that is the error then correcting the PCB is a trivial job.

Mike.
 
@qsiguy,

For CMOS, no special need is required for unconnected outputs. Only the input pins which by nature is high impedance should be pulled high or Low and not allow to float.
 
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eblc1388 said:
For CMOS, no special need is required for unconnected outputs. Only the input pins which by nature is high impedance should be pulled high or Low and not allow to float.

A NAND gate that has both inputs at zero will have a high output. The above circuit has the output tied to ground.:eek:

Mike.
 
Hi Pommie,

My post is to the OP, letting him know no connection to anything is required. It is not a comment to your post.

Sorry for the confusion.
 
Ok, the top schematic is supposed to be the good one, the board layout is supposed to have a problem. Since we are getting into the schematic issues I'd love to have some help understanding what you guys are all talking about. I didn't design this one, just helping a friend out to get some boards made for it. The circuit was made to work in it's "bad" version supposedly by "scrambling" the program in the EEPROM. I have no idea what that means or why it would fix a bad design.

This schematic is for a "piggyback" circuit board that holds two EEPROM chips that contain the ECU program for a car. It does work as the guy who originally supplied it has made dozens of ECU mods with this. He quit doing it and my friend has taken over the project so we are trying to get it going again. What the board does is allow you to have several different "tunes" within the ECU and use an external switch to change the programs.

I can't say if this diagram is the perfect way to accomplish this but I do know that it does work. Anyone know the easiest way to get this schematic into a board layout? I'm still waiting for the dimensions for the board. Do any of you want and have the ability to turn this diagram into a board layout? We are not looking for freebies, we will pay a reasonable fee.

If you guys need a better pic of the diagram let me know. I'd love for you guys to check it out properly.
 
PCBs

Hi qsiguy,

the layout looks very much like having been done by the autorouter. You can assume that the autorouter doesn't do anything wrong.

However I wouldn't expect proper function of a part of an IC with four inputs and two outputs tied to GND. (It's a short!)

Another reason for the bug could be an unconnected pin anywhere in the schematic or the wrong net used from the bus. You can only discover that by clicking every net and have the schematic editor highlight the connected pins. If just one pin isn't highlighted you have a bug, since it won't be connected on the board.

Perform an ERC first and if there is no error message (which should be in that case --> "only one pin on netxx")

If the ERC finishes without error message you should still perform your personal ERC as already described.

Furtheron the layout looks like having used the standard trace width of 0.012 inches (0.3042mm). Routing PLCC sockets it is advisable to reduce the trace width to 0.01 inches (0.254mm).

It is always a good idea to disable the top (1), bottom (16) and component (21) layer after routing is finished. You might have overlooked one connection which will be a bright yellow air wire. All you should have visible is pads and vias.

If all these measures fail send me the whole thing. I don't charge for the work and be done within two hours. The boards I'm normally concerned with have DIN-A4 paper size and bigger.

A bug starts at the schematic!

Send your file to hjzelec@freenet.de

Kind regards

Hans
 
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I appreciate your advice but much of what you are talking about is way over my head. I'm not sure what software was used to draw up this schematic. I'm also not familiar with the chips used on this. I'll be happy to send you the schematic file if you are willing to take a look at it. Do you make PCB's and can you make a board design from a schematic assuming it is right, or corrected if not?
 
Pommie said:
If that is the corrected schematic then you still have a problem Tying the output of a NAND to gnd when both inputs are also gnd is not a good idea. If that is the error then correcting the PCB is a trivial job.

Mike.

Can you be more specific as to the location of the inputs and outputs that are incorrect? Maybe mark up the diagram above in "Paint" and repost with some indicators of the problem areas?

Still trying to sort this out and that would be a huge help.
 
qsiguy said:
lol, yes. Thought maybe there was someone here that was a wiz at fabbing PCB's that would like the job. I'm waiting for word back from the guy that should know a little more detail on the problem issues as well as dimensions for the board and various specs.

Don't really need the board house to fix the problem, supposedly the schematic is fixed, just need it converted into a board. They can use the old board diagram as reference if needed.

Thanks for the advice, I'll check with that "custom PCB" place. Has anyone used this place?

PCB123 has arrangement for making PCBs from customers' drawings. Only thing is you may have to re-enter the whole work on PCB123 software and derive at the PCB layout. the software is free to download. it is located at

PCB123
13626 S Freeman Rd
Mulino Oregon 97042 USA
support@pcb123.com
 
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