To mutch power on core.......???

MIDIbox SID
1

Hi guys i’m building a sid 6581 a simpel one and i alrrady have a problem with constructing the core, i put it together ( i orderd a pack with the parts an PCB’s from mike in Germany… i think i did everything rignt but i get a different reading when i start measuring the core, i get 7,5 V everywhere… i don’t know what i did wrong, i checked the parts and now i don’t understand…i’m using a 9 V 600 mA walladapter…

now i have 3 parts left that might be worong placed…

i have 2 small withe keramic condesators i says .1J63 on top i think these are the

100 nF    there are suppose to be 3 of them in the pach but there are only 2 ( these have to be put on the back of your pannel)

but then i have another part very small it says 104 on the front it is smal and light brown, can someone tell me what it is ?

The i have one more thing i might have done wrong i might have connected the BC337 the wrong way could that make my power go up ???

Is the picture on the sheet of the core , is that form above or from below, because if it is from above i mounted it wrong…

I hope to get some answers soon so i can continu my project…

Thanks already…

Geert

2

Hi,

I’m making a wild guess about your power problem: You have put the regulator upside down.

Moebius

3

I don’t think so but i can try i let you know, i can;t take a picture right noe from monday again, but i mounted it exacly like the picture, if thats ok i lookt up the specs and i thoinkit is ok like this. The regulator is placed with the written side to the closed side of the board …??

anyone else… and my questions about the parts, i unpackt my sid module and foud out that the orderlist is different from the content of the kit???

Well will see first lets turn around the regulator.

Greating Geert

4

i see now that the voltage mesuments go up when i use a stronger adapter (12 V)

mabey the regulator is upsiddedown, ok first thing tomorrow…

Greet Geert

5

Hi Geert,

very good that you are measuring the voltages before stuffing the chips - otherwise you would have a dead PIC and SID now!

i have 2 small withe keramic condesators i says .1J63 on top i think these are the

100 nF    there are suppose to be 3 of them in the pach but there are only 2 ( these have to be put on the back of your pannel)

but then i have another part very small it says 104 on the front it is smal and light brown, can someone tell me what it is ?

the 104 is a 100nF as well.

The i have one more thing i might have done wrong i might have connected the BC337 the wrong way could that make my power go up?

no, only wrongly mounted the voltage regulators could be the reason

Best Regards, Thorsten.

6

hell, i tryed to switch the regulator but the power is going up this way i now get like exacly 10V enerywhere…

I checked my walladapter, it gives of around 12 to 13V in stead of the 9V like it sould, mabey i’m measurinbg the wrong way, but switching around the regulator did not have the right effect…

I’m ging to make my DinX now thats more easy…

Magey you got some more idears??? couse i’m out…

Greets Geert

7

when i use a stronger powersupply the voltage still go’s up all over the board, it is quite stable now but 10V is way to mutch

8

Post a (closeup, high detail) picture of your board please, it’s easier to see obvious mistakes that way. To me it sounds like a broken regulator. Your adapter could deliver more than the rated 9v if your mains power is also higher (could be 10%, so 12v instead of 9 is very high! cheapo powersupply perhaps?)

9

this picture shows, how to measure the voltages:

mbhp_core_extract_measuring_vdd.gif
mbhp_core_extract_measuring_vdd.gif800×815 58.1 KB

10

ok guys i think i lokated the problem, the polarety from my other adapter ( a boss 9V 200mA) and now i get 5.07V everywhere, thats ok isn’t it…???

But on the site they said you did not have to calculate the polarety?

Wel i think its ok so… thank for the tip about the folty adapter i hope it is ok like this…

ill soon be able to tell if it works like this…

Thanks Geert… ill place a picture tomorrow.

11

Ok i checked the voltages on the picture you placed TK but i dont get a 5V from the 

#25 pin fron the pic, i dont get it i do get 5 V at pin #26 strange ???

I’m checking it out…

12

TK is the picture you placed withthe PIC installed because it comes from the mide troubleshoting quide ???/

Thanks Geert

13

hi; if you build it with a bridge rectifier, it really doesn’t matter what the polarity of your adapter is.

i think that pin 25/26 only have 5 volts when the PIC is in the socket so if everything is fine exept these, maybe you can move on.

check also your adapter with yur multimeter if your not sure about that

good luck

14

thanks illog, ichecked my other adapters, they give like 3V higher than it says onthe front , i get 15V from a 12V, and 12V form a 9V adapter…??

Oh yeah about the polatery, i probebly connected the adapter in the wrong way so

the + to the - and the other way around. When i got the adapter that actualy gives 9 V the polarety was switched and it works like a charme,

i’m going to finisch my DIN first then for the test with my core.

TK are the voltages on #25 from the PIC also there when the PIC is not plugged in?

Thanks Geert

15

thanks illog, ichecked my other adapters, they give like 3V higher than it says onthe front , i get 15V from a 12V, and 12V form a 9V adapter…??

Actually non-regulated PSUs behave like this if not loaded.

TK are the voltages on #25 from the PIC also there when the PIC is not plugged in?

Yes.

Moebius

16

Yes.

Moebius

Well moebius i’m a beginner at this and i don’t want te sound wise ore something but i checked the scheet from the core… and as i see it it is not possible that there must be power on pin #25 of the PIC because that pin is only connected to to the midi out and the MD pin from J11…

i really don’t know if i’m seeing this right … can some one confurm this for me cause i don’t know what i’m doing apperently…

Thanks Geert

17

Your absolutely right! Sorry for that.

M

18

great than i think i can go ahead now… right??? it still bothers me that the other adapters dont give me the right power because te systen sould regulate this…

Well lets give it a go//…

Thanks Geert

19

yeah i finally got it, the stabel adapter gives me a nice 5 volt, but i still don’t understand about the other adapters but oke we can contineu…

I’m getting an upload code yiha lets put my sid mudule together…

Thanks guys ill be back with more questions…

Greets Geert

20

but i still don’t understand about the other adapters but oke we can contineu…

the reason for this issue would be really interesting, because I also have no explanation, why another adapter should lead to higher voltages behind the 7805. There could be a short at the bottom of the PCB, therefore it would be helpful if you could post a photo of the front- and bottom side of your board (you can send me the pictures, I will put them on the server)

Best Regards, Thorsten.