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Interconnection test troubles


tonysnail
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Hi all..

I'm currently performing the interconnection test between the my core and sid modules - i've got a steady 5.24v on every pin except for CS#..

I've continuity-tested the connections from the PIC pin RC5 to the SID pin CS# - and the connection is good.

So i checked the voltage on the PIC pin RC5, expecting it to be sending out the 5.4V, but i can't detect any voltage on it. Is this an indication that my PIC is broken? (I did smoke it a little with a poor power connection, which I've now fixed) - and every other function of the PIC appears fine.

I'm guessing CS# has something to do with the clock source for the SID, so I can see that potentially I may have fried this vital function when my SID started to melt..

Any thoughts? Is is it time to call Smash and ask for a replacement?

(Hope not! I'm soooo close to hearing the first phat sounds out of this leviathan!)

Cheers all!

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GGGGRRRRRR!!!

For some strange reason, I'm now only getting 10v on the SID 12v Vdd pin..

I traced it back to the SID board - i've got 14v coming in correctly to Sid:J1, and it reaches the topmost pin of the 7812.. But the 7812 is then only giving out 10v.. I replaced the 2200uf Capacitor, but it hasn't made a difference..

Strangely, I get 14v on the SID:Vdd and SID:Audio Out/In when the core module isn't turned on, but it goes down to 10v as soon as I power up the core..

I tried the testtone, and there's no sound coming from it now - I lost my super-quiet high-pitch whine completely, (except for the high-pithed whine I'm now making out of sheer frustration!)

Edited by tonysnail
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(Here's a diagram showing what voltages I have on the 14v power section of my SID board..)

I hope someone can help - I think this is the final hurdle before I finally get some sound out of the beast!

Could I take out the 7812, and bridge the top and bottom holes, and put a direct 12v through this board from a Wallwart? Or is this a bad idea?

post-6876-126024745528_thumb.jpg

Edited by tonysnail
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Just curious why the ground connection (middle pin) of the 7812 is cyan as well - that's supposed to be the 0V rail. So you should be measuring the 12V between the lower two pins of the 7812. It is possible that your 7812 is borked or it's not quite above the needed voltage. IIRC I've had an 7812 working on 13.5V and it worked nicely, so replacing it might be worth a try.

You could take out the vreg and bridge it and also remove the bridge rectifier but it's usually better to leave it in and not risk messing up the polarity ;)

Also, since it's not mentioned anywhere - you're using a 6581, right?

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Just curious why the ground connection (middle pin) of the 7812 is cyan as well - that's supposed to be the 0V rail. So you should be measuring the 12V between the lower two pins of the 7812. It is possible that your 7812 is borked or it's not quite above the needed voltage. IIRC I've had an 7812 working on 13.5V and it worked nicely, so replacing it might be worth a try.

You could take out the vreg and bridge it and also remove the bridge rectifier but it's usually better to leave it in and not risk messing up the polarity ;)

Also, since it's not mentioned anywhere - you're using a 6581, right?

Hi Nils..

Firstly - yeah, I'm using a 6581..

I performed the multimeter test between the vreg ground (middle) pin and the vreg lineout (pin nearest the SID), and i'm only getting 0.2v.

With the multimeter negative on the ground lead of my 14v power source, and the positive on the MB_SID 14v in pin, i get the correct voltage, so I can see that the correct voltage is reaching the MB_SID board.

And with the multimeter negative on the same ground lead, I can see the same 14v reaching the voltage in of the vreg - so the correct power seems to be reaching it..

I replaced the Vreg with another 7812 - and still I get the same problem..

So although I assume isn't the vreg that's causing the problem, since I replaced it and still get the same result, I can't work out what the problem is, since the correct voltage seems to be reaching it, yet the wrong voltage is being given out..

Maybe part of the trouble is I'm not sure which ground lead I should be attatching my multimeter to - and as a result I get different results..

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So, I bridged the Vreg and I'm now sending 12v straight to the SID..

With a rather substantial amount of background noise that I'll deal with later, I'm getting the test-tone loud and clear!

But now, once I upload 'setup_6581.hex' - the core reboots, and says "Launching CS"

It then flashes what I assume to be an error message, and reboots.. And repeats this over and over again.. Apart from once, when it booted up normally after I left it for a while (at which point the sid wasn't powered so I couldn't check if was working :-( - and after that, nothing..

Maybe i've blown up my PIC after all.. Other apps upload OK (i.e. setup_8580.hex, setup_MB6582.hex) and go into synth mode, but setup_6581.hex - the one I need - just keeps rebooting)

Any thoughts on this?

Edited by tonysnail
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