Is this a capacitor?

[Spork Schivago]

Re: Is this a capacitor?

...
So basically, the positive of either the internal battery or from the external power supply (wall wart, or what ever power source you are using to plug into the DC jack) will ALWAYS connected to the Cathode of the protection DIODE D7, the negative will ALWAYS be connected to the Anode of D7, D7 is in reverse bias mode so it will not conduct. I will conduct if the polarity of the battery or the external power supply is wrong.

Thank you for the explanation. However, I did actually just verify the polarity of the power supply I'm using and it is in fact correct. Negative on the pin and positive on the shield, right? I verified it by checking the continuity by placing the probe on the positive part of the battery holder and placing the other probe on the outer shell of the jack and it reads 0. I also did the same for the negative part of the battery terminal and the center pin.


When I flip the board over, if I put my negative probe on the ground part of the DC jack (where it solders to the board) and the positive probe on the diode D7 (either cathode or anode side), I get a reading of around 8.45VDC...

[Spork Schivago]

Re: Is this a capacitor?

Here's some pics...

[budm]

Re: Is this a capacitor?

" positive probe on the diode D7 (either cathode or anode side), I get a reading of around 8.45VDC" That is not correct if you are getting the reading on either Cathode or Anode because the Anode is connected to the Negative of the DC input jack. Ground pin (negative) of the DC jack is pin1 (center male pin), so I do not see how you can get the reading on the Anode.
So let do this, remove the internal battery, Plug the DC plug into the DC jack, the DC plug you are using has two wires, take the resistance reading of one of the wire and the Cathode of the D7, one of them should read less than one Ohm, mark that wire as positive, the other wire then should show less than one Ohm when read it with Anode of the D7, that is the Negative wire.
From your pictures I just saw, the positive of that 9V battery clip should show 0 ohm between the Cathode of D7 and the Positive of the battery clip. Same 0 Ohm between Negative clip and the Anode of D7, you can see that in the diagram.
by the way, what is that black thing in picture number 2?
So with that 9v battery and the battery clip and the barrel connector as shown in the last picture, that setup should work.
The PSA120 looks to be regulated power supply.

[Spork Schivago]

Re: Is this a capacitor?

"...take the resistance reading of one of the wire and the Cathode of the D7, one of them should read less than one Ohm, mark that wire as positive, the other wire then should show less than one Ohm when read it with Anode of the D7, that is the Negative wire."

I did that and could only get a reading for the positive wire. I got 0.00ohm when I put it on the cathode side (I even got a reading on the anode side...doubt it matters though).

When I tried the other wire, I just got OL (overload), no matter what side of the diode I put it on. When I check the continuity between that wire and one of the pins on the DC jack (the solder part on the board), I get a reading of 0.00ohm. However, when I follow that circuit and try and check the continuity on a part right above it, I get OL. It has to be something with that pin. I'm going to try and remove the solder and see what it looks like. I'll brb.

"From your pictures I just saw, the positive of that 9V battery clip should show 0 ohm between the Cathode of D7 and the Positive of the battery clip. Same 0 Ohm between Negative clip and the Anode of D7, you can see that in the diagram.
by the way, what is that black thing in picture number 2?
So with that 9v battery and the battery clip and the barrel connector as shown in the last picture, that setup should work.
The PSA120 looks to be regulated power supply.

I don't know what a regulated power supply is. Does that mean it's working alright? I think we're really close to figuring this one out. Good call on the continuity test.

[Spork Schivago]

Re: Is this a capacitor?

Oh, I don't know what the black thing is. It's in the middle of the cord, between the wall wart and the jack end....

[Spork Schivago]

Re: Is this a capacitor?

I think I found the problem! I removed the solder and there's no pad under there. Just board...no copper at all. When I was melting it, there was some weird flaky stuff in the solder. I bet that was the solder pad! Can I just run a jumper wire from that DC Jack pin to maybe something like C37? If I follow the circuit path, it looks like that's the next part in line...

If I did so, would the ground cover everything on that path? Or would my jumper just provide ground for that C37?

[budm]

Re: Is this a capacitor?

Regulated power supply means that the Line voltage 120Vac for US, and 230Vac for Euro can be fed into this power supply and it will maintain 9VDC out put, as shown on the sticker, this power supply can take anything between 100Vac up to 240Vac and it will maintain 9Vdc output, the non regulated power supply output voltage will go up and down if the AC line voltage goes up and down.

[budm]

Re: Is this a capacitor?

Show me the pictures of that damaged pad then i can tell you where to put the jumper wires.

[Spork Schivago]

Re: Is this a capacitor?

Nice. One quick question. If something like this takes a 9VDC 200mA wall wart, could I use a 9VDC wall wart with any amperage so long as it's 200mA or higher? Say I had something like 2A...could I use that? Thanks.

[Spork Schivago]

Re: Is this a capacitor?

I want to put a jumper to where the screw driver points to. Can I?

[budm]

Re: Is this a capacitor?

You can use higher current rating power supply, but not lower, it just means that the higher current has more capacity, just like AA battery has more current capacity than the AAA battery even though they put out the same 1.5Vdc. The voltage should match, it will depend on the equipment if it can tolerate lower or higher voltage or not, best is to match the voltage.

[budm]

Re: Is this a capacitor?

Yes, that is the correct point for the jumper wire to the DC jack, you can use the resistor leg as the jumper wire.

[Spork Schivago]

Re: Is this a capacitor?

bingo! Should I now test it with the weird wall wart? The one where the amps where jumping around?

[Spork Schivago]

Re: Is this a capacitor?

I was going to use a regular wire for a jumper but that resistor leg worked perfectly. Looks real nice.

[Spork Schivago]

Re: Is this a capacitor?

Works perfect with the wall wart too. Now I just have to try and remember how it goes back together. It's 2:17AM here. I should of been to bed a while ago but I really wanted to get this done so I could work on some other stuff. Thank you so much BudM!!! I love this place.

[budm]

Re: Is this a capacitor?

Thanks for great news. I am going to bed too, see ya.

[Spork Schivago]

Re: Is this a capacitor?

Thanks again BudM! I got it all back together. I should of been able to figure this out. I thought there was a short some wheres. I was removing the components and testing them right next to jack, but I never thought to actually remove the solder on the jack because I was getting voltage when I touched the probe there. I'll have to reread what you wrote earlier about the schematics and how it works. I'm not very good at reading them. I'm starting a book which should teach me how this stuff all works. I want to design my own circuits one day. I'm reading a book called Electronic Circuits for the Evil Genus. If you know of any other good books that explain how this stuff works in lay man terms, please let me know.