Something is stopping power and lowering it to the half . .

[dcreatorx]

Hi again ! I've got the new pair of RC4 core module pcb's : Great for SmashTV . . this design seems to be more versatile and bug free than the latests. I've got a small prob. Everything is well mounted as I did with taken all the care required for the situation, but now I'm getting 2.5V instead of the normal 5V required when realizing a Vdd measure from the MIDI troubleshooting. Can you tell me why it happens ? Maybe I'm missing new instructions for these new cores ? I see here that I get exactly the half of 5V where I have to get the whole 5V.

A think to say : If I connect ground from the PSU to the core power SIL header, it gives me the 5.20V. I think is after the entrance of the power that gets lowered. But . . . I checked and everything is ok, I think it's my best solder since I started. Thanks again . .

[dcreatorx]

Hi again . .  I mounted the second core I have with even more care and I get the same results. I'm getting a bit desperate here. Some help would be much appreciated. Thanks.

[dcreatorx]

I'm using the optimized PSU. Do I have to remove the IC3 voltage regulator ?

[Altitude]

on the core you need to remove voltage regulator (5V will be coming from the PSU) do (and short the pins)

[dcreatorx]

Ok now I'm going better, I get 4.68V, wich is not enough to start the system. What could be that I'm not reaching the normal 5.20V ?  ? Thanks . . 

[dcreatorx]

Hi ! I have mounted my new core modules and, when I measure the critical points with the multimeter I get 4.60V instead of the 5.20V that should normally give back. I'm using the optimized PSU, so the Voltage regulator is removed and the pins are shortened correctly too. The PSU is right, as it gives the right voltages when measurinn it and even when measuring the J1 ( power pins ). The board has no soldering errors as I double checked and everything seems to be fine. Can somebody give me a hand with this ? Thanks.

[ganchan]

Probably your multymeter is out of alignment like was mine. I had +4.80V instead 5.20. You must open it and turn the trimmer since you have 5.20.

If you can first, test it with another C64PSU, if you have 4.60 your tester is out =)

[dcreatorx]

Thanks for your reply but I must say that I tryed to sync the core to my PC with the MIOS STUDIO and It does not work. I get no response from the core. If I measure the the J1 power pin, It gives the right voltage. Seems that after the power connector it looses somewhere. As I get no response from core when I try with the MIOS STD., I think that the won't be that issue with the multimeter. Thank you, and help is much appreciated.  :-\

[TK.]

Just to ensure (I'm not sure if there is a misunderstanding of the circuit, or something else...): which voltage do you measure at J1 of the core module?

Best Regards, Thorsten.

[dcreatorx]

I measure 5.20V measuring from the optimized PSU ground to the J1 p.pin. Thank you T.

[TK.]

Are you really using the optimized PSU circuit? (http://www.ucapps.de/mbhp/mbhp_4xsid_c64_psu_optimized.pdf) - there is no connection to J1 of the core module...

Best Regards, Thorsten.

[dcreatorx]

Thanks T. I'm feeling like an idiot . . . I didn't remember that the right connector with the optimized PSU was the J2. Now I get the right 5.20V everywhere it should. Now the bad news : I did already all the MIDI troubleshooting, even the loopback with the IN/OUT ports of my PC and I can't get a sign of the PIC. Maybe It's dead ? Thanks again.

My gameport is working properly and my MIOS ST. config is the following :

PIC and the optocoupler are on the right place too. As everything is working, what can happen ? I've got the LCD ready to assemble. It wold be better to mount it for a better debugging ? Thank you.

[Altitude]

It wold be better to mount it for a better debugging ?

Oh yes.

I would have gone completely insane debugging mine if it wasn't for my LCD

Getting everything to work is like old testament God: lots of rules, no mercy  ;D

[dcreatorx]

Ok I will assemble it now. Can you tell me how to start the debug process after that ?  Thank you.

[dcreatorx]

I'm here once again, I can't mount the LCD yet. I don't have any ICD connectors so I'm waiting for a new smashTV order. I tested the second new core, and the same happens ! Does that give you any sense of what is happening ?

Thanks.

[TK.]

You wrote that you did the MIDI troubleshooting, but you are not writing about the results of each test.

E.g., it would be interesting, if the IO loopback without PIC is working:

Best Regards, Thorsten.

[dcreatorx]

Hi T. ! Thanks for your help, it is always much appreciated. When I do the I/O loopback test I don't receive anything on the input monitor.

[TK.]

Ok, so the PIC is propably running, but the MIDI interconnections are not working.

When you are doing (really) all the tests, you should be able to find out the root cause.

Shortcut: most people just swap the pins on the MIDI In and/or Out jack

Best Regards, Thorsten.

[dcreatorx]

I think isn't the interconnection . . . It's a R4C core and I'm using the PCB mounted MIDI jacks

I'm doing PC Out to MIDI IN and viceversa and the software port config is good.

One more question. On the R4C you have the option to assemble the PCB with standard to-SIL jacks or the PCB mounted included. Do I have to solder the rest of the pins remaining reserved for the SIL connections. Just for ask. Thanks.

[smashtv]

Do I have to solder the rest of the pins remaining reserved for the SIL connections.

No.

Best

SmashTV

[OrganGrinder]

hi

back to the original discussion

i also had the problem of about 1/2 the voltage when testing a core, i thought it was a problem with the voltage regulator.  turned out that i had not soldered the bridge rectifier properly, a resolder and the it core tested perfectly.

hope this helped

OrganGrinder

[dcreatorx]

Hello . . . that problem is solved. I get the right voltages everywhere now. Thank you.

[stryd_one]

Hey dcreatorx, why not share what you have learned to solve the problem? That might help others in the future :)

[dcreatorx]

No, my problem still here, I can't get to communicate the PIC with my computer. But the problem with the voltage was solved few posts ago . . . thank you for your help and dedication, is much appreciated.

[OrganGrinder]

HI

i know this is a silly question, but is the 6n138 oriented the right way.  I noticed that SmashTV's Core_R4 (which is what i'm using) has the 6n138 oriented "upside down" in relation to the pic.

also (and this seems silly too) have you tried swapping the M+ and M- wires on either midi in or midi out (assuming you are not using a pcd mounted 5pin din on the core), i found that i needed to use a crossover connection with the core's midi out to a casemount 5pin din.  if you have a close look at the tracks for the midi out on the core_r4 you will see why the crossover is needed.  i believe this was done so that when connecting 2 cores directly to each other, a crossover wire would not be needed.

and please, my reference to a crossover wire is NOT in reference to a standard midi connection wire, but the connection between a core and a non-pcb mount 5pin din socket.

OrganGrinder