OEM stamp...
multi_coder
Posts: 3
I started in to basic stamps a while back, played with some code and sensors and now I am stuck. I bought a OEM Basic stamp 2 and built it, and when I attach a battery it over heats the wires leading to and from the battery and starts to smoke. If I hook the battery to the BOE basic stamp board I have the battery works fine. [noparse][[/noparse]Its a 6.0v set of 750 millamp battery tied together in a chain of three]. I looked at the sodering on the board and can't find any wrong leads connected. Where else could the problem be?
Post Edited (multi_coder) : 8/13/2009 8:31:39 PM GMT
Post Edited (multi_coder) : 8/13/2009 8:31:39 PM GMT
Comments
Are the processor·and EEPROM plugged in correctly?
Do you own an ampmeter or VOM?
Unplug both procesor·chip and the eeprom.
Unplug the DB9 connector.
Disconnect the battery.
Use VOM to measure the resistance between + and _ terminals on the OEM board.
What is the reading?
If you do not have VOM find 200 ohms to 1kOhm resistor and connect in series with the battery and than connect the battery to the board. Keep the processor and the eeprom out of the sockets!
If the resistor gets warm quickly you have a short somewhere on the board.
Post Edited (vaclav_sal) : 8/14/2009 1:21:38 AM GMT
The OEMBS2 can be a little tricky to assemble.I hope You applied power to the Vin pin and NOT the Vdd pin or both.
If so all is not lost. Parts can be replaced with ease on the through hole designed OEMBS2.
Some more info and maybe some pics of Your work(on the OEM) would help this along.
________$WMc%________
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The Truth is out there············································ BoogerWoods, FL. USA
Huh???
Do you mean three (3) ·6Volt batteries in series connection??
I hope not!
·
First rule of electronic building - always check for shorts first before applying power.
Next rule – use limiting resistors in series with your battery ·( 100 ohms minimum for 50 ma at 5V – I would use at lest 250 ohms to be sure ) or limiting current power supply just to make sure you are not drawing· too much current. Idle stamp should not draw more that 50 ma, but I have never actually measured it.
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With all your IC's removed use your meter·to measure resistance between Vss Vdd and Vin.
Anything around 0 ohms spells trouble.
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Did you solder the DB9 connector tabs? You may have shorted the tabs to the near trace.
But I cannot tell from the picture.
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I cannot·see the bottom of mine and do not remember if they should be soldered. ·I think they just snap in.
Vdd - Vin -> [noparse][[/noparse]all settings] == 1
Vdd - Vss -> [noparse][[/noparse]all settings] == 1
The D9 connectors are soldered in.
I checked for shorts and all connections that are not the D9 casing are showing 1.
I will look and see if I have any 100 or 250 ohm resistors lying around to add to the battery circuit.
The polarity on the filter cap is correct.
Failing that, take the regulator out and see if that cures the problem. Maybe its a dud.
What is the " U " ???... Do you mean 1 ohm ? if so like mentioned above check for a shorted solider joint or a faulty reg.
I read 9.36Kohm from Vss to Vdd and an open loop from Vss to Vin.
This is the fun but sometimes not so fun part of the hobby. The fix to this problem will teach you alot about how the hardware
works. After you fix it, Your head will swell and you'll feel like the man. And then you move on to the next challenge.
___________$WMc%_______
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The Truth is out there············································ BoogerWoods, FL. USA
2 Vdd - Vin -> [noparse][[/noparse]all settings] == 1········· ??· open across regulator input and output
3 Vdd - Vss -> [noparse][[/noparse]all settings] == 1········· ??· this should be same as above #1
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Remove the regulator and measure it again.
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The main measurement is Vin to Vss· and Vdd to Vss
Vdd to Vin should read open·without the regulator.
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Use as little heat as feasible.
Some boards are not build to resolder components and will fall apart on you.
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I was talking about the DB9 mounting tabs, not the connection pads.
I they may be connected to ground via cable shield and it looked like you may have some solder bridges there.
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I think you have a bad regulator. They are not bulletproof.
Post Edited (vaclav_sal) : 8/16/2009 2:26:09 AM GMT