Please Help!!

[StevieG]

Hi could anyone tell me how to fix this please.

[budm]

Re: Please Help!!

What kind of components that fit into those holes? If they are through hole components, I would use 24AWG solid bare wire and wrap the wire aorund the component's legs then solder, then I would apply epoxy glue on top of it.

[StevieG]

Re: Please Help!!

What kind of components that fit into those holes? If they are through hole components, I would use 24AWG solid bare wire and wrap the wire aorund the component's legs then solder, then I would apply epoxy glue on top of it.

RD15HVF1 RF Power Transistor

The thing is most of the track as come off as you can see in picture. i gave it to a mate who said he could fix it and ended up coming back looking like that.
he burnt the tracks with the soldering iron and took the track off. i just can't see where it joins as im not good at this sort of thing.

http://www.ebay.com/itm/2pcs-MITSUBI...05%26rk%3D1%26

[budm]

Re: Please Help!!

OK, you trying to figure out how all the legs of the components are hooked up to each other and the orientation of the transistor due to the old copper traces are gone.
Can I see the top side of the board then I may be able to figure out which hole is the the Gate of the transistor.

[StevieG]

Re: Please Help!!

OK, you trying to figure out how all the legs of the components are hooked up to each other and the orientation of the transistor due to the old copper traces are gone.
Can I see the top side of the board then I may be able to figure out which hole is the the Gate of the transistor.

Top Part of board.

[selldoor]

Re: Please Help!!

What is the board part number and what is it off

[StevieG]

Re: Please Help!!

theres no number on the board. its of a fm transmitter. Chinese i think it is.

[StevieG]

Re: Please Help!!

ive been looking at the board for over 2 weeks now, but i just can't see whats what. its just a maze to me. i just hope it can be fixed

[budm]

Re: Please Help!!

OK, This MOSFET is used for the RF Power amp putput stage, Pin 2 of this MOSFET is SOURCE pin instead of DRAIN pin like other MOSFET, but since it is made for RF circuits which need to have minimum stray capacitance in the construction of the silicone die and the internal lead connection, they make pin 2 (middle pin) as a source pin.
Please se picture and spec sheet on how to put this MOSFET in place.

[StevieG]

Re: Please Help!!

OK, This MOSFET is used for the RF Power amp putput stage, Pin 2 of this MOSFET is SOURCE pin instead of DRAIN pin like other MOSFET, but since it is made for RF circuits which need to have minimum stray capacitance in the construction of the silicone die and the internal lead connection, they make pin 2 (middle pin) as a source pin.
Please se picture and spec sheet on how to put this MOSFET in place.

Many thanks for that i will give it a try now and let you know how it all go's

Steve

[budm]

Re: Please Help!!

Just make to see the spec sheet on the pin out. Good luck.

[StevieG]

Re: Please Help!!

Just make to see the spec sheet on the pin out. Good luck.

hi again. soldered that as in picture. but no power getting through the board when switched on, maybe a break on a trace somewhere ?

[budm]

Re: Please Help!!

Do you get the power before? Can I see the whole picture of the board so I can see where the power is applied and the way you have install the MOSFET?

[StevieG]

Re: Please Help!!

2 mins i get a picture

[StevieG]

Re: Please Help!!

Do you get the power before? Can I see the whole picture of the board so I can see where the power is applied and the way you have install the MOSFET?

There was power before my mate burnt the track off the board. but i never tryed it without the rf resisstor.

heres a couple of pictures of the board.

[selldoor]

Re: Please Help!!

Might seem a silly question but where does the power feed into the board and what voltage is it?

[budm]

Re: Please Help!!

That power cable? (the gray cable on the bottom right of the board as shown in pic1, see if there is shortes circuits there, see if you have any voltage on that blue electrolytic by that gray cable.
I see a DC input jack by the gray cable also.

[StevieG]

Re: Please Help!!

That power cable? (the gray cable on the bottom right of the board as shown in pic1, see if there is shortes circuits there, see if you have any voltage on that blue electrolytic by that gray cable.
I see a DC input jack by the gray cable also.

No voltage there. the grey cable is to switch it on. and your right thats where the 12v dc power go's. ive got no way in testing the board as i don't have a metre

[budm]

Re: Please Help!!

You need the meter for sure, do not leave the power connected since you may have short circuits somewhere or you may have bad power source, power switch, etc.

[StevieG]

Re: Please Help!!

You need the meter for sure, do not leave the power connected since you may have short circuits somewhere or you may have bad power source, power switch, etc.

Just tested it by touching the 12v dc wires straight 2 the circiut board and it powers up ok. but when trying to power up through the proper way nothing happens.