Renard 64 assembly

[Elmo2resc]

does the long or short lead go into the square holes for the led's?
Does it matter on the resistors and capacitors?
I think i goofed on 64 leds, I probably should have asked sooner...
Thanks for any help....Jerome

[P. Short]

I can never remember, I always have to figure it out anew.

The square pads on the board are the anodes, the round ones are the cathodes. From the mouser catalog it looks like the convention is that the short leads on LEDs are the cathode...so short lead goes in the round hole.

For resistors it doesn't matter. For the caps, it only matters for C1 and C2, where the square pad is positive.

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Phil

[Dan Ross]

On the Olsen 595 the cathode went into the square hole.

[P. Short]

For some reason the layout package used here wants the square pad (pin 1) to be 'positive'. Since I'm never sure about LED polarity, I don't solder them in until I've applied power to the board and test-place it (without solder) to make sure they turn on.

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Phil

[Elmo2resc]

well, I placed all the long leads in the square holes. everything that was marked with a dot was placed with the dot at the square. Everything else was placed as it was marked on the board or the only way it would fit. Is there anyway to test the board before i get my ren-t ? I hope these are all right. Thanks, Jerome

[wingrunr]

Conventionally a square hole indicates negative leads meaning the short leads should go into the square hole. I do hope that is the case because I soldered all of my LEDs that way.

Is the square pad positive throughout the entire board? If so, I soldered my diodes on incorrectly as well as my capacitors. There really needs to be information regarding assembly in the wiki.

I'd like to know if I have done this correctly for using the Ren-T to bring the ZC in. I have jumpered J2-2 and J2-3 together, created a power input on U1-2 and U1-3 where U1-3 is +5 volts. I then jumpered U2-2 and U2-3 together. I have soldered on the C2 capacitor. J1, R1, R2, C1, D1, and U6 have not been soldered on.

Also, what is the purpose of J17 and R3? R3 is not on the BOM and J17 isn't mentioned anywhere I can find.

[P. Short]

The polarized caps C1 and C2 are the other way around - the square pad is '+'.

For the non-LED diodes, the square pad is the cathode (as indicated by the silkscreen symbol).

For the LEDs, the square pad is the anode.

As for the other parts that you mention, it depends on how you are planning on bringing power in to the board (you have J1, J2, R1, R2, and U6 correct, the other parts depend on the power).

J17 was intended to allow the PICs to be programmed on the board with a special adaptor cable (which hasn't be designed or documented). R3 has no purpose now that everybody is using the external oscillator, and should not be installed. Previously, it would have been used in conjunction with the LED labelled 'DIAG' to provide additional status.

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Phil

[BillAd]

On the Ren-64 board I'm not clear which pins to jumper on J2. I'm planning on using option 1 where ZC is obtained through the input connection J4. I also have the voltage regulator and filter cap installed to power the board from this same source. With this configuration should I connect pins 1 and 2 (nearest the PCB edge) or pins 2 and 3? Thanks.

Bill

[wingrunr]

Well switching all those LEDs around is going to be fun. The power LED is included in the anode-is-positive thing right? Also, I'm bringing power in via a PC PSU via U1-2 and U1-3. Do I need the C2 cap for that? And, just to make sure, the square pad is positive for the capacitors correct?

Perhaps it would be a good idea to update the PCB layout so that the square pads are the cathodes as is the norm.

[P. Short]

The wiki has been updated with information about how to install the diodes and caps (the square pad on the caps is positive, the polarity of D1, D4 and D5 is indicated on the silkscreen).

It's a good idea to install the cap C2 regardless of where the power comes from.

You're right about updating the LED pads on the board (although it may be a while before there's an update). Also, the silkscreen should indicate the polarity of the capacitors better, and the non-rectangular LEDs should have a polarity indication in the silkscreen as well (there isn't room for a polarity indication on the silkscreen for the rectangular LEDs).

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Phil

[Elmo2resc]

Phil, I believe that the BOM also needs corrected. It list Diode 78-1n5239b as D4 (right). Shouldn't it be D5 now?
Jerome

[P. Short]

Yes...

[wingrunr]

So I have removed all of my LEDs and am in the process of flipping them around. I think that many of them accidentally ripped the pads off the PCB though. Is there a way to fix this. It would suck tremendously if this board was ruined.

Well I'm not getting good connections on virtually all of the LEDs where the pads were damaged. I bought the parts for this specifically so I could have the LEDs and to use the PWM firmware. The fact that this PCB is non-workable now isn't very good. Everything else is assembled on it too, so who knows what else could potentially get damaged as I start removing components. The diodes are resistors are almost worthless because I trimmed the leads so short. Bah...

[P. Short]

Unfortunately, I don't have much experience in reworking PCBs. My more usual tendency (bad, I know) is to scrap the boards and work on new boards.

If it were my board and I was trying to save it (due to long lead times or the expense of the other parts already soldered onto it), I would forget about the LEDs (since they are probably destroyed already in the process of removing them). What I would do then is to use an ohmmeter to determine where there are opens between the PIC and the RJ45 connectors (and visually inspect to make sure that the lifted pads are shorting things together), and use insulated wires on the solder side of the board between the PIC and the RJ45 connectors. I would start with the first PIC (U10), and the power up the board to get the first eight channels working, and then later go on to the other 56 channels.

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Phil

[wjohn]

So I have removed all of my LEDs and am in the process of flipping them around. I think that many of them accidentally ripped the pads off the PCB though. Is there a way to fix this. It would suck tremendously if this board was ruined.

I am with Phil on this one. at less than 10$ a PCB, I'd scrap the bad board and start fresh.

If you were talking about a 1000$ uController, i could talk you thru some ideas i have used in the past to repair boards.

[wingrunr]

I will attempt a repair and see what happens.

[grages]

Here is an article on "Green Wire Fixes"

http://www.sparkfun.com/commerce/present.php?p=SMD-HowTo-5

On the other hand I think its like John said at ~$10 you might be better off getting a new board. Let me know if John doesn't have any, I have one I am not using this year but bought for the future.

Shawn

[bonuts]

The power LED is included in the anode-is-positive thing right?

The WIKI says "The anodes of the status LEDs (long lead) go in the holes with the square pads. " So just to confirm, does this also apply to the power LED? Thanks.

[P. Short]

Yes.

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Phil