Hi there. I've been brought a pocket recorder for repair.
The guy told me he used a wrong adapter (didn't tell wich) and it stopped powering up.
It works on power adapter and/or 2xAA batteries, none of them seem to be working.
I coudn't find any schematics, so I started a component check starting from the dc power connector.
Have to say I do repair stuff for years at a medium level, but I'm no technician and really new to smd repair.
I found this component marked with U30 wich seems to be 0ohm throught it's terminals. Also the opposed terminals in the middle section are connected to ground, but I cannot identify it.
On it's left, it has a throught hole to the other side of the board, wich seems to go to a VR and first two transistors (also a zenner diode pack). The thing is I can't get anny conductivity if I touch on both sides of the hole, neither on the terminal of the components on each side.
Could ever one of this "connected holes" loose connection?
Then I found this d2 diode I thought it was shorted (checked on both sides). Lifted it and seems to be ok. There is a short on the pads, also seems to be a short on the u12 component.
There seems to be also a short on the U16 component, wich is the same as described on the first picture, but this shows continuity in between all 4 pins.
I've checked pretty much every voltage regulator, transistor, electrolicyc condenser and resistor on the board, so I'm kind of stocked.
I don't dare to apply voltage with this short (if there is really one, since i measure Mohm on the dc power connector between + and -)....
If any experience, how far can one of this blows go? It could have been applied 12v instead of 5v or reversed polarity, or both. I never got to know.
Thanks.
The guy told me he used a wrong adapter (didn't tell wich) and it stopped powering up.
It works on power adapter and/or 2xAA batteries, none of them seem to be working.
I coudn't find any schematics, so I started a component check starting from the dc power connector.
Have to say I do repair stuff for years at a medium level, but I'm no technician and really new to smd repair.
I found this component marked with U30 wich seems to be 0ohm throught it's terminals. Also the opposed terminals in the middle section are connected to ground, but I cannot identify it.
On it's left, it has a throught hole to the other side of the board, wich seems to go to a VR and first two transistors (also a zenner diode pack). The thing is I can't get anny conductivity if I touch on both sides of the hole, neither on the terminal of the components on each side.
Could ever one of this "connected holes" loose connection?
Then I found this d2 diode I thought it was shorted (checked on both sides). Lifted it and seems to be ok. There is a short on the pads, also seems to be a short on the u12 component.
There seems to be also a short on the U16 component, wich is the same as described on the first picture, but this shows continuity in between all 4 pins.
I've checked pretty much every voltage regulator, transistor, electrolicyc condenser and resistor on the board, so I'm kind of stocked.
I don't dare to apply voltage with this short (if there is really one, since i measure Mohm on the dc power connector between + and -)....
If any experience, how far can one of this blows go? It could have been applied 12v instead of 5v or reversed polarity, or both. I never got to know.
Thanks.
