Cycle Analyst gone blank?? Please help :/

[scorpi00n]

Hey, Ive screwed up my CA and hope someone here can help me get it going again.

I was trying to connect an led to the CA using "v+" and "G" when I accidentally connected the wires to "v+" and "5v". Now all LED's on the CA are working but I have no display.
I tried changing the position of the "G" coming from the controller to another spot but still no display. Also I find it weird that the display LED's are still working even when the "G" coming from the controller is not connected?

Any help would be greatly appreciated.

[dnmun]

sounds like it is toast. maybe justin can help.

[heathyoung]

Ouch. LED's working (backlight) just means that there is current flowing through the voltage regulator. (prereg prior to the 5V reg)

V+ to 5V means you probably dumped your pack voltage (minus led drop) across the microcontroller. They short internally when you subject them to this kind of punishment, so the backlight will work just fine, just nothing else will.

Its probably screwed dude... If you are lucky, it just took out the 5V reg. Maybe.

[scorpi00n]

So couldn't I just get a new microchip and dump the firmware in it?

[scorpi00n]

Ouch. LED's working (backlight) just means that there is current flowing through the voltage regulator. (prereg prior to the 5V reg)

V+ to 5V means you probably dumped your pack voltage (minus led drop) across the microcontroller. They short internally when you subject them to this kind of punishment, so the backlight will work just fine, just nothing else will.

Its probably screwed dude... If you are lucky, it just took out the 5V reg. Maybe.

I think you may be right about the 5V reg. I just got it going.
I gave the microchip an external 5V supply and BANG, its alive!

but....

It's displaying a usage of 1800w and has 89V coming in when there is no load on it other than the led's on itself and my supply is 75V + 4.9V from the external source.
I have checked what the out put of the 5V is and its only putting out 2.3V. Another issue is something is getting really hot in there.
Heres some photos to explain;

This is where I get the 2.3V reading from and also where I gave it an external 4.9V


and this is where its getting hot enough to bubble the soldering under the black thingo,

[heathyoung]

Yep its probably your 5V reg thats shorted to ground, when you remove it, you will get the pre-reg not running so hot (pre-reg is 12V IIRC?).

At least the micro (pic16f690) isn't dead.

You may also have killed the tantalum capacitor as well. They short and will show similar symptoms. Throw a multimeter across the tantalum and see if it is shorted.

The opamp (that scales the current) not sure where it gets its supply from, if it is using the preregulated (12V) output, is probably not getting the correct voltages and is having a brainfart - dunno if it is rail-rail or not (in which case it would be running off the +5V rail (thats how I designed mine).

[scorpi00n]

Yep its probably your 5V reg thats shorted to ground, when you remove it, you will get the pre-reg not running so hot (pre-reg is 12V IIRC?).

At least the micro (pic16f690) isn't dead.

You may also have killed the tantalum capacitor as well. They short and will show similar symptoms. Throw a multimeter across the tantalum and see if it is shorted.

The opamp (that scales the current) not sure where it gets its supply from, if it is using the preregulated (12V) output, is probably not getting the correct voltages and is having a brainfart - dunno if it is rail-rail or not (in which case it would be running off the +5V rail (thats how I designed mine).

First of all thanks for the reply!
Now I have a few questions in regards to what you have suggested;
1- Where is the 5V reg (how do I identify/replace it)?
2- I have tested the tantalum capacitor and it doesn't seem shorted. I'm getting a reading of about 803Ohms across it. Is it ok?
3- Opamp, don't really know what to do about that one...

I think my main issue at the moment will be fixing the 5V problem and see how it goes from there.
So if you could at-least help me out with that, it would be great.

[dnmun]

what is the part number on the 3 terminal regulator that had the melting solder? your external supply is going through that and overheating it. you should replace that regulator i bet, but not sure.

[scorpi00n]

what is the part number on the 3 terminal regulator that had the melting solder? your external supply is going through that and overheating it. you should replace that regulator i bet, but not sure.

No part number, just black.

[heathyoung]

The black thing that is melting the solder isn't a regulator, its a power mosfet being used in its linear region as an amplifier for a zener regulator. Its being overloaded with a load on its output, which is most likely the 5V regulator. Tantalum measures fine at 800 ohms.

The 5V reg is a 3 terminal device (small) 7805 or something like that. Higher resolution photos would help a bit in identifying it, but it should be close (follow the tracks) to the positive side of the tantalum cap.

[scorpi00n]

The black thing that is melting the solder isn't a regulator, its a power mosfet being used in its linear region as an amplifier for a zener regulator. Its being overloaded with a load on its output, which is most likely the 5V regulator. Tantalum measures fine at 800 ohms.

The 5V reg is a 3 terminal device (small) 7805 or something like that. Higher resolution photos would help a bit in identifying it, but it should be close (follow the tracks) to the positive side of the tantalum cap.

The only device with 3 terminals are the ones ive circled in the pic's. Also added the PCB layout which may help you identify the 5V reg.

http://img195.imageshack.us/img195/9058/boardhd.jpg
http://img151.imageshack.us/img151/605/carev11.jpg

[heathyoung]

Looking at the picture, I would say it is the component marked as U3. The 5 legged bugger next to the tantalum cap. The pinout fits (SOT23-5) exactly.

How much current were you drawing on the 5V rail? And on the Vbatt side?

Stupid conformal coating makes it hard to read component values. I like the sticker over the micro prior to conformal coating - beats sandng the chip numbers off I bet

Farnell (element 14) have them in stock for $0.70 each...

http://au.element14.com/micrel-semicond ... tt=MIC5205

[scorpi00n]

Looking at the picture, I would say it is the component marked as U3. The 5 legged bugger next to the tantalum cap. The pinout fits (SOT23-5) exactly.

How much current were you drawing on the 5V rail? And on the Vbatt side?

Stupid conformal coating makes it hard to read component values. I like the sticker over the micro prior to conformal coating - beats sandng the chip numbers off I bet

Farnell (element 14) have them in stock for $0.70 each...

http://au.element14.com/micrel-semicond ... tt=MIC5205

I seem to be in a bit of a dilemma at the moment. Ive been in contact with Justin from ebikes.ca (thanks heaps btw) and he suggested that it may be the op-amps
He has informed me that the unit should normally draw 7mA from the supply and once the op-amps are removed it should draw the same. But if it draws over 10mA that the PIC or LCD module may have suffered.
Will be getting myself a soldering iron tomorrow to try that out and see how we go.
Whats your thoughts on that Heath?

[dnmun]

you can just cut the 5V leg open on the op amp. no need to unsolder it to test it. you need sharp dikes that will be narrow enuff to get in there. cut it midway so you can solder the leg back together later if it is not the culprit.

or if you have a soldering iron now you can heat up the pad and leg until the solder melts and pull the leg up with a small pick.

[binlagin]

I'm having basicly the same issue with my CA.. unfortunately I'll just end up buying a new one

[scorpi00n]

you can just cut the 5V leg open on the op amp. no need to unsolder it to test it. you need sharp dikes that will be narrow enuff to get in there. cut it midway so you can solder the leg back together later if it is not the culprit.

or if you have a soldering iron now you can heat up the pad and leg until the solder melts and pull the leg up with a small pick.

How do I know which leg is the 5V?

[dnmun]

it will be soldered onto the 5V supply trace. or look it up in the technical pdf.

[scorpi00n]

Thanks to everybody who tried to help out but I've given up and decided to get another CA.