Surf PI Pro

[jimfrombr]

Hi, well I put it in the orientation the circuit board indicated, as you read the writing on the chip Pin 1 is the bottom left. I found a schematic on page 8 or 9 that identified some voltages to check on some of the runs. I may take the socket out and replace too. Thanks for the reply. I am also buying Silverdog's board. I have to read the chips and study the schematic, I am geologist and my electronics is limited to a circuits class and college physics which was almost 40 years ago.

[porkluvr]

I posted two images of the board I completed....

Ummh, and where might these images be? Help us out and maybe we can help you out.

[jimfrombr]

Hi porkluvr, post #898 in this thread I put an top view and a bottom view of my board. I have been trouble shooting with all ICs out except 7660 and the voltage check failed for -5V at pin 5. I swapped ICs with the same results. I started reading through the threads and found a schematic and a post #273 that identified some tracks and voltages I should check. Which I planned to do. I am pretty sure I have the components in the right place. Thanks for reading and replying to my posts, any insight or direction is appreciate. I also ordered silverdog's kit.

[porkluvr]

There they are... sure 'nuff. I missed them and I just did not feel like hunting any more.

Alright, maybe I should already know this from the board you are using, but I don't, and I should have asked before: whose schematic have you followed? (And if you would, either post it, or else post a link to it, or state which post number where it can be found).

I haven't lurked in Geotech1 in a number of years and this Surf PI thread had a bunch of different variations back in 2012, or whenever it was... and there are probably even more variations now. That's my guess, anyway.

Hmmm, and all my old files on another hard drive that I do not have connected to my new system.

Meanwhile, you could try disconnecting anything that you have connected to the 7660 pin-7 and see if you get -5V by NOT synchronizing to the transmitter which may not be working.

(Of course you realize that the 7660 output needs to be working before you can ever expect the 5534 to be OK. Right?)

I need to do some computer maintenance for a couple of hours... maybe rearrange my "office"... who knows. But I'll be back (before the year 2020, I suppose).

[jimfrombr]

Thank you so much for taking the time to look at my problem. Here is the schematic of board I am working,. I am a new to this so I expect to do alot of searching and testing i have already learned a lot from the others.

[porkluvr]

Thank you so much for taking the time to look at my problem. Here is the schematic of board I am working,[ATTACH]36255[/ATTACH]. I am a new to this so I expect to do alot of searching and testing i have already learned a lot from the others.

That is not a schematic you showed in 906, that is a PCB layout. It has a components overlay and that is a plus, but sometimes it is easier to describe what is happening if there are reference designators i.e., R1, D2, etc. Your component overlay is not comprehensive in that regard, for instance, the diode connected to ICL7660 pin-7 is not labeled.


So, did your kit come with a schematic?


Regardless, you need solder wick and probably some liquid flux to do a good job of what comes next:


Disconnect everything connected to pin-7. To do that, unsolder one end of the diode (you know which one), and unsolder one end R17. Gently raise those leads, try to do so without damaging the components. Then, unsolder IC6-5 (ICL7660 pin-5). Don't try to raise pin-5, just try try to isolate it from the surrounding copper trace.

(Use some alcohol or water to clean up the mess, depends on what kind of flux!)

Then try so see if you have -5V, measured directly on IC6-5. If no, then you may have a defective C14.

You have -5V, yes or no?

Supposing you have no liquid flux and no solder wick: ( )

Just because IC6 does not have an output, that does not mean it is bad. There could be something wrong with one of the other components connected to one of the IC6 pins.

You should suspect the diode, C14, T1, or anything that is connected to the -5V trace. Use your multimeter to try and find low resistances between the leads on any of those components.

[jimfrombr]

unfortunately, I didn't get a schematic with the kit, I searched this forum and found what I believe is the schematic but there may have been mods I am still learning. But anyway this is what I have . I have solder wick. Thanks for the direction this will be fun sorting through. I will certainly let you know if i am successful. Thanks

[porkluvr]

(I probably shouldn't have told you to go and start desoldering stuff) Of course you don't have liquid flux... so....

before you go and start desoldering a bunch of things, you could maybe use your multimeter and try to check for shorted components around the IC. I told you where to start.

Liquid flux makes desoldering something sooo much easier (and safer). Don't tear nothin' up.

Google on how to check diodes and capacitors for shorts.

Remember, you check for shorts with NO power applied. Leave the power off.

[jimfrombr]

I have liquid flux I used a while back on a Geiger counter I built that had memory sockets and computer chips. I can follow instructions pretty well but by no means am I an electronics technician. I well poke around before desoldering, I am not concerned about screwing up the board further a little headache will teach me a lesson.

[jimfrombr]

Well I couldn't find any opens or shorts on the board continuity looked good every where (following, blue, brown green traces in the parts layout drawing I had). I am going to disconnect the components recommended and check the capacitors and diode. I bought two kits from and the same time and either by DMM (exotech 430) capacitor function isn't working or I got a bunch of bad capacitors in the kit. I am on a step learning curve but I am making progress.

[jimfrombr]

Success Thanks all that helped I have my -5V and was able to adjust the offset R10 to 0V.
I had to disconnect the D4 diode, and the three (C13,C14, and C15) capacitors and checked, replaced one capacitor. Cleaned my board with good technical grade isopropyl.
What I learned. First read the posts and study the circuit and components, ask for help after you know how to ask the right questions. Get good equipment if you can (I Bought a good Fluke DMM). Wash with good Tech grade isopropyl, check all your components and continuity.

[porkluvr]

Good deal. I was starting to get worried because some problems can get really sticky.

[jimfrombr]

I am not out of the woods yet, I still have issues but I will try to work through them but I will probably back here looking for help.

[jimfrombr]

Well I have volume, a solid tone the pot seem to work, but I cant trim R10 to 0V at pin 6 of NE5534P I can get to to down to +0.56 V and then it start going up or erratic. I am listening through piezo buzzer which probably is not the best. I attached a photo of my board and the coil (spiral wound 24 awg double wire 30 winds) which was recommended. When I was adjusting R10 I had threshold set at constant whine just above no sound the other controls accept volume where set at their mid-range position. I had the proper +5v and -5V pin 5 of ICL7660 and pin4 of NE5534. First question is should I be able to get 0V at pin 6 of NE5534P and does the POT positons for delay volume and sensitivy affect the measurement when zeroing? Thanks in advance .

[jimfrombr]

I replaced ICL 7600 and couldn't get the voltage to trim to 0V at pin 6 of NE5534P I then replaced NE5534P (they shipped me a NE5534AP) after this I could get the R10 to trim to 0V at pin 6. Al my POTs seem to adjust the tone one way or another I don't have good audio so I cant actually tell if the coil is responding to targets in the house.