Kenwood ts-430s Transistor Q21

[KD2DBM]

My Kenwood TS-430s won't go into transmit again. Transistor Q21 on the IF board is open. I know this as I had the rig recently repaired for the same problem, and testing Q21 shows that it is open. The problem I have is that the middle pin of the Transistor will not solder to the PCB pad becasue the Pad is not there.....My questions are, Can I take and replace the Transistor with another like a 2N3906 in place of the transistor that is there now, and can I wire the middle pin somewhere where I can get the radio to transmit...I would actullay like to wire all 3 transistor pins to where they either draw power from or what ever....SOMETHING so that I can get the rig back on the air...it is a GREAT rig and the recieve is out of this world...so if anyone can help me out I would appreciate it... I am disabled and do not have the money to keep sending out the rig for repair. I have looked at the schematic and my small amount of Knowledge in reading schematics does not do me any good so I thought I would seek help here from Fellow hams who have allot more knowledge than me...any help would be greatly appreciated.

Bill, KD2DBM

[K8AXW]

Bill:  Sometimes you have to revert to brute force and ignorance! 

Whenever a pad is lost on a PCB, then the only thing that can be done is to wire that particular lead to where its supposed to go with a short piece of wire.  Might look trashy but it's really the only option, within reason.

[KE4DRN]

hi Bill,

Here is a yahoo group for the ts-430

http://groups.yahoo.com/group/ts430/


73 james

[KA4POL]

Q21 is a 2SC2703 NPN Ic 1A type. The 2N3906 is a PNP at Ic .2 A. So the answer is a multiple No!
The comparison types are to be found under: http://alltransistors.com/crsearch.php?mat=Si&struct=NPN&pc=0.9&ucb=30&uce=0&ueb=5&ic=1&tj=150&ft=150&cc=13&hfe=100&caps=TO92
And, of course, a pragmatic approach is fine under the circumstances given.

[KD2DBM]

The information I have been given so far is AWESOME. Thank you guys so much, but it doesn't really answer my root question. Where would I wire the leads of the replacement transistor? I have VERY LIMITED knowledge when it comes to reading a schematic so I have no Idea where I would wire the transistor leads to. My solderiong experience is however VAST and I am VERY good at it so that won't be a problem I just would like to know when to solder the leads to...Thanks again in advance.

Bill, KD2DBM

[W9GB]

The problem I have is that the middle pin of the Transistor will not solder to the PCB pad becasue the Pad is not there.
My soldering experience is however VAST and I am VERY good at it so that won't be a problem.   I just would like to know where to solder the leads to...

The skill set of PCB (printed circuit board) repair is taught in comprehensive soldering courses and certification for military, government, industry, and space assembly or repair work.

BEST teaches these courses on a regular basis in Chicago area and throughout the US/Canada
at various technical or vocational schools for soldering certifications.
Videos links (demonstration of proper work techniques) are on their web ite.
http://www.solder.net/products/pcb-repair-products

BEST -- Soldering Tips (Videos) on PCB pad and trace repairs.
http://www.solder.net/technical-info/soldering-tip-videos

DIY Solder pad and trace repair requires GOOD Lighting, Magnification of work area, proper tools/supplies, and PATIENCE.  Outstanding work is achievable, but does take time.
For those that do not desire DIY Repairs, there are firms that specialize in PCB repair work.

[KA4POL]

When saying 'pragmatic approach' I meant just solder the middle pin to the closest by trace. There is no problem as long as the connection is there. I've sometimes soldered a part to the bottom side of the PCB. Whatever suits your needs is fine.

[KD2DBM]

I should be able to do that, (soldering the pins to the closest trace), for all 3 pins am I correct?

[KA4POL]

Absolutely correct.