PTH08000 Help! Keeps smokin!

[Teamxiyo]

okay so I ordered a PTH08000 and a PTH08080 when hooked up using diagrams like harsh boy, the chip starts to smoke, ive looked over all connections and can't figure out what im doing wrong, in the process ive fried 2 n64's . The little black chip with white bit is the one getting fried. the pic below shows the PTH08000, but ive fried the other one as well.

I'm Using Ni-Cd 3500mah 8v (measured) from portable DVD player

[timmeh87]

Well it looks like it is hooked up right. Tell us more. Did it break before or after you connected it to your N64? (please tell me you didn't just hook it up without testing the output voltage!). Was it ever properly working or does it blow up as soon as you switch it on?

That looks like what happens to chips when you give it too much or backwards voltage. Are you sure your multimeter probes aren't in backwards? lol.

[snowpenguin]

Yep, that happened to me once when I gave it reverse voltage.

[hailrazer]

Is that cap hooked up backwards? Looks like the negative side is on the bottom when it should be on the top ?

[Teamxiyo]

Without connecting the n64 it started burning the PTH, i mean i have a 8v pack and it says + but the wire is black and - is red which is weird cause its backward. This is most likely the reason. The cap is hooked correctly, negative to negative. Is there a surefire way to test the batteries neg and pos outputs without looking at the wires to see which is which? Thanks for the help guys.

[snowpenguin]

Multimeter.

[Teamxiyo]

hmm seems either way i connect the pos and neg it starts to smoke, gonna order another ti chip.btw snowpenguin how would i go about using multimeter to check which is pos?

[hailrazer]

hmm seems either way i connect the pos and neg it starts to smoke, gonna order another ti chip.btw snowpenguin how would i go about using multimeter to check which is pos?

Well of course it gonna smoke now, it's toasted. Once it's fried it doesn't miraculously start working again.

[timmeh87]

Yeah it really sounds like your multimeter is hooked up wrong or something.

You dont test what way is right by trying both ways.

The red wire is gonna be positive 95% of the time

[technoforlive]

once fried always fried thats what i got to say

jees if you dont change of course its gonna smoke to infinite

[ToastBucket]

...btw snowpenguin how would i go about using multimeter to check which is pos?

Put the red end of the multimeter on what you think is positive and black on what you think is negative. switch meter to volts and if the bar goes to a positive number or the line goes to the right, its hooked up right. if it goes to a negative number or left it's backwards

[timmeh87]

...Assuming you stuck the red probe in the red hole and the black probe in the one that says "COM"

[ToastBucket]

I see a few problems, not necessarily why your regulator's smoking but, 1. You won't be getting 3.3v from that regulator with that resistor there. You need ideally a 1.87K resistor but you could just put in series with a 10K and get 1.8 which would be good. 2. that ground to n64 line shouldn't be there. the ground input should be connected to the n64 and screen as well as regulator instead of that ground output to n64. <--don't think this is necessary, its just good measure

[ToastBucket]

resistors should be in parallel not series....soz