Nesp Almost Complete...NEED HELP!

daguuy · Post by **daguuy** » Thu Nov 03, 2005 7:34 pm

oops, forgot about that

minkster · Post by **minkster** » Sat Nov 05, 2005 11:39 am

I got my multimeter today...its a digital 15 range one. I read the instruction booklet but it looks confusing. It has has ranges like ACV 200v, 500v/DCA 200mA,20mA,2mA/ DCV 500v,200v,20v,2v/and so on. I'm a little clueless on what I should set it to, and where to put the positive and negative test leads. And do I test it while the battery is turned on with the screen?

mattb419 · Post by **mattb419** » Sat Nov 05, 2005 12:52 pm

Hey Minkster, here's what I know about the multimeters (anyone who might know more feel free to step in

)

- You're working with DC power, so you want to use a DCV setting. Generally, I try to set mine to the lowest number that is still bigger than the current I'm pushing through. So for testing on the mobo, pc boards and such, I'd use the 20v setting. However, if you haven't removed the inverter from your psone screen, don't go poking around it, it puts out a ton of voltage. Another reason why I like the LED mod

- You can touch the negative lead to the ground on the NES mobo (metal areas around the edge of the board... there's a good spot around where you removed the RF box!). Then touch the positive lead to the spots where you want to check the voltage.

- Yes, you want everything turned on with the battery.

Here's a couple places I'd check. Power in to the nes board (5v). the power to psone screen point on your right pc board (around 7.5 volts). and the video to screen point in your video amp (about 1.7 volts I think). You can also check the volts at the 7805 that powers the nes, to make sure that it's getting more than 7.2 volts at the unregulated power-in point.

let us know what you find!
-Matt

minkster · Post by **minkster** » Sat Nov 05, 2005 1:28 pm

mattb419 wrote:Hey Minkster, here's what I know about the multimeters (anyone who might know more feel free to step in )

- You're working with DC power, so you want to use a DCV setting. Generally, I try to set mine to the lowest number that is still bigger than the current I'm pushing through. So for testing on the mobo, pc boards and such, I'd use the 20v setting. However, if you haven't removed the inverter from your psone screen, don't go poking around it, it puts out a ton of voltage. Another reason why I like the LED mod

- You can touch the negative lead to the ground on the NES mobo (metal areas around the edge of the board... there's a good spot around where you removed the RF box!). Then touch the positive lead to the spots where you want to check the voltage.

- Yes, you want everything turned on with the battery.

Here's a couple places I'd check. Power in to the nes board (5v). the power to psone screen point on your right pc board (around 7.5 volts). and the video to screen point in your video amp (about 1.7 volts I think). You can also check the volts at the 7805 that powers the nes, to make sure that it's getting more than 7.2 volts at the unregulated power-in point.

let us know what you find!
-Matt

I'm writing this down as you speak! Thanks!

minkster · Post by **minkster** » Sat Nov 05, 2005 2:30 pm

Well boy am I glad I got this multimeter because now I know for sure my voltages are copulate up

So here is what I tested:
Nes (place where
RF box was): 1. Video Out- 0.05V
2. Audio Out- 0.24V *
3. 5V-0.03

Right PC Board: 1. +7.5V to screen- 8.12V (OMG I GOT ONE RIGHT!)
2. Unregulated Power in- 9.69V
3. Ground to Screen- .03V
4. +5V- .03V

Left PC Board: 1. Video in from NES- .05V
2. Video out to Screen- .05V

7805: 1. Unregulated power to NES/Input pin- 9.98V
2. Middle Pin- 0.00V?
3. 5V out- 0.03V

*- For audio I noticed I disconnected the wires going into the PSone screen, so possibly the voltage could have changed.

Also for each connection I did what Matt said by putting the negative test lead on the RF box ground area.

So yeah, I realized I have a lot of wrong voltages...mostly coming from the NES. I have no clue where to begin

I should probably change my thread title because it looks like im not quite finished with this portable yet.

nos_slived · Post by **nos_slived** » Sat Nov 05, 2005 2:39 pm

It sounds like the problem lies with your 7805. Are you sure you don't have it backwards? Input goes to left pin, ground is center(which is why you got 0V), and 5V+ out is the right pin. If you have that right, you probably have a bad 7805.

minkster · Post by **minkster** » Sat Nov 05, 2005 4:23 pm

nos_slived wrote:It sounds like the problem lies with your 7805. Are you sure you don't have it backwards? Input goes to left pin, ground is center(which is why you got 0V), and 5V+ out is the right pin. If you have that right, you probably have a bad 7805.

Nope, I have it in the right order...when I used to plug the NES up to wall power the 7805 would get hot, but now it doesn't. Therefore I believe its dead. I will replace it with the original 7805 on my NES's rf modulator that I desoldered. I'll see if the NES works, and if I have new voltages. Thanks for telling me the idea

mattb419 · Post by **mattb419** » Sat Nov 05, 2005 9:10 pm

I think nos_slived is right too

Sounds like the power to the screen is good, you just need the 5v to run the nes... if your extra 7805 doesn't work, send me a PM and I'll send you one (got an extra from work that I don't need)

-Matt

minkster · Post by **minkster** » Sat Nov 05, 2005 10:19 pm

Well earlier I switched the 7805 and quickly reconnected every wire. Then I went to turn it on and nothing happend. So then I turned it off...and realized a wire from my phono jack fell off...and I thought it went onto the switch. So then I turned it on and all of a sudden the wire smoked and literally burnt off all the plastic on it...it scared the crap out of me

I looked in the book later that the wire was supposed to connect to the power switch input wire, which is connected to the power switch. I just reconnected everything and I'm a little shaky to turn it on and find out what happens.

EDIT: I had the balls to turn it back on...the screen only lit up and no smoke came out anywhere, but I went to turn it off and it won't. My guess is I have one of the wires on the wrong spot from the switch causing the NES to have no power, but the screen to just power up. I will take a look at this tomorow. I do think nos_slived is right though. Once I have the connections right I believe I will be getting the proper voltage. If I found out the 7805 regulator fried from this incident I have another one as a backup

jeff19 · Post by **jeff19** » Sun Nov 20, 2005 8:21 am

Hey minkster, keep at it. Ive been reading your thread and it look slike youre overcoming a lot and youre almost there! Its nice to have some help and guidance along the way too. Ive been having the same problem you have. The screen lights up but no video. Im going to go check all my voltages right now and see whats going on. Keep in touch and well learn from each other and help each other figure it out.

By the way nos_slived and Matt, thanks for your guys help with me in my thread so far. Im still not done but even so I appreciate the time and effort of you guys to help me with ideas (and also the tolerance of my inexperience

)

By the way Im posting all my reults and troubleshooting efforts in my thred which is "Newbie needs troubleshooting NESp connections, screen, video" in the "Hacking Videogame Consoles - The Book" forum. I know I didnt realize there was a separate NES forum at the time I posted, but oh well its better to keep all the previous conversations in the same thread for now to avoid confusion.

minkster · Post by **minkster** » Sun Nov 20, 2005 1:35 pm

Thanks

I've read your thread that you can't seem to power up the screen,or get the green bars for volume and such. You may have to look back at your video amp, and its a good idea to get a multimeter. As of now, the project is on hold until further notice...school work is sometimes in the way,but I'm not giving up. Good luck on yours too..it will be nice to see another NES portable with the original board

jeff19 · Post by **jeff19** » Sun Nov 20, 2005 7:50 pm

I do have a multimeter, the problem is I'm not really sure how to sue it or where to test. For instance I don't know which end to put where (positive, negative) when I'm testing the connection between two components/spots. I still get confused easily since Im new at electronics the flow fo the circuits and everything still loses me a little. Like I said before without getting those green bars at all, I think the screen just isnt getting any power. But like I ALSO said before, Im having a hard time figuring out how to test that theory. People say "test the video in volts" but im still not really sure exactly how to do that and all. Argh, so frustrating

Well hopefully we will figure it out sooner or later!

minkster · Post by **minkster** » Tue Nov 29, 2005 6:10 pm

UPDATE: Well, after being frustrated with my NES, I decided to send it out to a portablizing genious (I wont tell you who yet) And he took a look at it, and found out one of my grounds had a loose solder joint, and the 7805 was shot so he replaced it. (yup thats right after three previous 7805s by me, he finally got one to work

) So anyway, the good news is he tested the sound and it works perfectly, and then he tested the video on his tv and that also works too! The bad news is my screen has two missing parts

Compared to his psone screen, mine has two missing resistors...which could have also been the cause of a faulty screen display. Well right now he is going to radioshack to put in some resistors to see what happens, and hopefully the screen will work succesfully. Me=HAPPY

I will update any news on this almost finished portable asap

jeff19 · Post by **jeff19** » Tue Nov 29, 2005 6:47 pm

Good for you! Seems like your problem was simple and is easily remedied. I on the other hand believe i Had a bad psone screen so i bought another one and lo and behold i finally get those green bars to show up! This tells me the screen works fine. But I still cannot get a video signal. I think I know who you sent your NES to but i wont say either if youw ant to keep it a secret

I feel I probably have a relatively simple problem with mine as well, but like you, i think i may need an expert to take alook at my solder joints. I have a feeling something like that or a bad component (perhaps a resistor is shot). Which 7805 was shot, the one on the NES motherboard?

Why was your screen missing 2 resisitors? Just a defective product to begin with? Or do you mean you didnt add the two resistors when you were supposed to, according to Ben's book?

minkster · Post by **minkster** » Tue Nov 29, 2005 7:39 pm

jeff19 wrote:Good for you! Seems like your problem was simple and is easily remedied. I on the other hand believe i Had a bad psone screen so i bought another one and lo and behold i finally get those green bars to show up! This tells me the screen works fine. But I still cannot get a video signal. I think I know who you sent your NES to but i wont say either if youw ant to keep it a secret I feel I probably have a relatively simple problem with mine as well, but like you, i think i may need an expert to take alook at my solder joints. I have a feeling something like that or a bad component (perhaps a resistor is shot). Which 7805 was shot, the one on the NES motherboard?

Why was your screen missing 2 resisitors? Just a defective product to begin with? Or do you mean you didnt add the two resistors when you were supposed to, according to Ben's book?

Well, it wasn't exactly easily remedied...well at least for my sake going through three 7805s not knowing what the heck would stop the portable from working

The 7805 that was shot was the one on the NES motherboard by where the RF mod. used to be. Also, when I bought my screen I'm positive it didnt have the resistors already on it. So yes, it was deffective...if it wasn't for the guy who compared it to his screen, I would have been stumped

Well I do have a new update...the resistors were put into my screen and BAM! Perfect sound and video! My controls are being checked next for any upcoming problems, but besides that, everything seems to be working out fine and then should hopefully be shipped back to me.