Surf PI Pro

[6666]

You can get probes on fleabay
if you can afford it, try and get two channel.

[sdesic]

last night I desoldered everything associated with LM358 on PCB and it still has that effect on -5V
socket gets +5V and -5V... and when I place IC in socket I loose -5V

must try that IC on other device I have again

I am on the way to get one channel oscilloscope which has no probes for testing

[Davor]

You may try here http://www.njuskalo.hr/index.php?ctl...nce&sort=cheap
It worked for me.
No way you can do any meaningful measurements in PI without a real oscilloscope.

[sdesic]

Can anyone help with this problem?
Where can I find oscilloscope test points?
Graphs for surf pi pro ?

[sdesic]

You are saying that with all IC's in the board there is no -5v
but take them out and the -5v returns.
I had a similar fault it was a faulty 5v regulator
it could not handle the load with all IC's plugged in , what voltage do you have on the input to 7660
with all IC's in the PCB ?

7660 is working on other surf pi pro ... changed with new one and same thing happens
with all ICs in place 7660 gets its +5V
on pin 5 there is +0,5V

located problem close to LM358 ...
when I take out that IC -5V returns
something faulty ... resistor or capacitor maybe...

[6666]

You are saying that with all IC's in the board there is no -5v
but take them out and the -5v returns.
I had a similar fault it was a faulty 5v regulator
it could not handle the load with all IC's plugged in , what voltage do you have on the input to 7660
with all IC's in the PCB ?

[sdesic]

As I mentioned before I have problem with my surf pi pro
-5 V is not there when all ICs are in place

-5V is there when I pop out all ICs
I returned all IC same thing, so I returned all but LM358
there is -5V ... replaced with new but same thing happens
no -5V on 7660 or on other places

Any ideas ?

I had problems with one missing capacitor
220nF capacitor was missing and I used one older (224K 250V type) and one new 63V

[liekwang]

?Ok I'll try it later thanks for the info

[sdesic]

you can look for my post here

http://www.geotech1.com/forums/showthread.php?18655-Surf-PI-Pro&p=170497#post170497

and follow steps by Jose and others
read fist and then try something...

you can replace R2 with trimmer 5k for beginning
use more than 3k3 and you will gain more depth but it can overheat IRF and take more power from battery

[liekwang]

?I've tried to use the coins made of allumunium less sensitive with silver ring I wear a motorcycle battery voltage 3, 5am do not use an adapter from ac to dc

[sdesic]

You should try working on batteries or power cell which is not AC-DC adapter... some disturbance comes from AC power
try working on 8 x 1.5V batteries or 12V lead sealed battery 1.2Ah or better
try different AC adapter if you can

If you have one plain 1,5cm coin you should try that so we can compare
I have 1 EURO coin on 15 cm ... other coin can be found on 20 cm ... composition and size of coins are different

[liekwang]

?I use 12volt dc 3, 5am

[liekwang]

?The wire that I bought I can't wear gauge coil wire count only enamel copper colored jumper IRF9640 0,5 330omh 2watt and I do not understand the induktasi coil I but less sensitive silver ring sdesic I do not understand about electronics but merely a hobby and I'm also not the engineer is capable of if I exsperimen coil can detect gold ring in 30 cm what do I do

[sdesic]

I think best results are with 21 cm coil 25 turns 0,4 mm copper enamelled wire
can you measure you coil with LRC meter ?
what is resistance of coil ?
what is inductance of your coil ?

[liekwang]

?Surf long Board arberg gold ring size 2.5 cm sensitip in the air between the strong voice in 17 cm 24 cm voice coil diameter 20 cm start weak. 25 Coil wire 0, 5 mm but less than 10 cm silver ring.