ren 48lsd Help

[buymyemu]

Virtus, about to try your hex file. What failure symptoms did you have?

[budude]

Stick with the hex files from the File Library - they are the "official" versions and are known with 100% certainty to work. I'm sure Virtus's are more than likely the same and will also work - but let's keep things simple and start from a known good start.

Let's concentrate on the voltage to pin 2 of the PICs - if that isn't right around 2.5v then nothing will work. Pull PICs 2-6 and leave just PIC #1 in and we'll concentrate on getting channels 1-8 working first. Once that is working then you will have a known base to add on to. Check the oscillator orientation - the squared corner should point to "DC IN 1" (upper/right). Check the traces/solder joints along the entire path from all the pin 2s back to oscillator.

[buymyemu]

All PICs pulled but 1

Oscillator square is to upper right dc in 1

Traced from the oscillator, looks like it goes
4,3,5 6/1/2

retouched all pin 2's

No other components allong that trace, right?
Still checks at about .95 v on all 6

[buymyemu]

Just to make sure...

I am checking pin 2 with the positive lead on Pic pin 2 and the negative lead on the dc in 1 negative screw.

I verified orientation of all components that required orientation. I check all resistors to see if any shored or open. Nada

So.. to me, (I know little about hardware), the voltage regulator section works (5v on pins 5/8 and 5 volt pins 1 to 14).

Would an oscillator fail with these symptoms, or just be dead?


Should I order a new oscillator, is it possible I used too much heat when I soldered it, can it be damaged if dropped?.

If so, should I order anything else? Pic's since I bend the legs every time I remove them.....

[budude]

Just to make sure...

I am checking pin 2 with the positive lead on Pic pin 2 and the negative lead on the dc in 1 negative screw.

I verified orientation of all components that required orientation. I check all resistors to see if any shored or open. Nada

So.. to me, (I know little about hardware), the voltage regulator section works (5v on pins 5/8 and 5 volt pins 1 to 14).

Would an oscillator fail with these symptoms, or just be dead?


Should I order a new oscillator, is it possible I used too much heat when I soldered it, can it be damaged if dropped?.

If so, should I order anything else? Pic's since I bend the legs every time I remove them.....

Anything is possible - I know of at least two cases where the oscillator was bad - I can't think of anything else to try to be honest. PM your address to me and I'll send you another oscillator to try.

[Materdaddy]

If you're bending the legs of things, you should order an IC puller.

I have a really cheap Radio Shack one I can't recommend because it bent when pulling an IC that was in fairly tight: http://www.radioshack.com/product/in...ductId=2103244

I also have this one from mouser, and it is really nice: http://www.mouser.com/Search/Product...ualkey801-EX-6

[buymyemu]

Brian,

Can't believe the oscillator got here today! Thanks you for the speed. Spent a while with my braid and got the old osc. out, broke off the ground leg. Soldered the new osc in

Got the same output: about .95v to pin 2 with or without a pic.

spent the last 3 hours probing/measuring resistors, tracing circuits, measuring voltage across pins, looking at the schematic, etc.

Decided I was going to wire up the old osc outside the board and measure the voltage. Looking for wire I stumbled across my second voltmeter.

Second voltmeter reads 2.16 v on pin 2 Mastercraft 052-0060-2
First voltmeter reads .95v on pin 2 gb instruments gdt-11

Both read 5v on pin 1-14 and pins5-8 of the little chips.

So:
1) Why would the voltmeter not measure oscillator voltage output correctly
2) Is 2.16v on pin 2 enough
3) I ask because I have 5v on pin 5 with a test sequence running, and MM output


Hmmm... I stopped and ran my test sequence, full on channel 1 ten sec, channel 2 etc.

pin 3 was zero till i started then went to 5v
pin 13 went to 5v at 10 sec

looks like I have a working PIC?




I am going to double check my wiring from the lsd to the Might Mini.

[buymyemu]

Brian, I have to apologize for wasting your time.

The board works fine.

Pics may not have been programmed originally but the real root cause is the polarity on my output to the Might Mini's. I just assumed that the wire with stripes was common and the solid was positive. I checked with a volt meter and they needed to be switched. All works now, wasted 1 oscillator.

And I also have a bad volt meter that led me down the wrong path.

Should have:
Checked outputs at the mighty mini terminals
Checked outputs on the PIC pins 3 and 13

But I know more now than i did,

Thanks for the help, I will replenish

[budude]

Well - it sounds like it! Most voltmeters have a very high impedance across the leads so that they don't interact with the circuit too much. It's possible your GB meter has an issue. Anything around 2.5 is good so 2.16 is probably OK. I would shorten the time a bit - maybe 2 seconds so you don't have to wait quite so long for the transitions.

[rfallatt]

I was wondering if someone could help me determine if my board is toast or not. Can this be fixed?