• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

Sm50 powered reverse polarity

Status
Not open for further replies.

KYPLOW

Member
Joined
Mar 3, 2013
Messages
4
Reaction score
0
Location
West, Kentucky
Friend was installing a sm50 and used a cheap adapter with colors reversed for the power plug now radio won't do anything the m2535l diode fell out in housing I've checked it and it shows good so I re soldered it but still nothing. Where do I look, or is it a lost cause? Thanks in advance.
MATT
 

cmdrwill

Member
Joined
Mar 30, 2005
Messages
3,984
Reaction score
377
Location
So Cali
The m2535l diode is supposed to blow the fuse in the power cable with reversed polarity, but got way overloaded. No FUSE ...
In some models in that series there is a small fuse on the '12 volt line' to the logic section that blows. But before the big diode blew it self off the board other damage may have already occurred.
 

kruser

Well Known Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
5,096
Reaction score
1,439
Location
W St Louis Cnty, MO
The m2535l diode is supposed to blow the fuse in the power cable with reversed polarity, but got way overloaded. No FUSE ...
In some models in that series there is a small fuse on the '12 volt line' to the logic section that blows. But before the big diode blew it self off the board other damage may have already occurred.

Yep, the external fuse(s) should have blown in the power cable well before the diode heated up so much that it fell off the board!
Once that diode fell off the board, the reversed polarity would have passed to the rest of the radio at the full potential of the power supply.

Hopefully the OPs radio did just blow the fuse feeding the logic section.
 

KYPLOW

Member
Joined
Mar 3, 2013
Messages
4
Reaction score
0
Location
West, Kentucky
Thanks fellas, I don't believe there was a fuse in his power cord lol. I didn't see any fuses on the board but I may not know what I'm looking for. Is it a very small glass tube fuse or something similar? I'll try to post a picture when I get in tonight.
 

com501

Member
Joined
Sep 28, 2003
Messages
1,615
Reaction score
428
Location
127.0.0.1
Green picofuse that looks like a resistor near the rear accessory connector. Check it with an ohmmeter.
 

Project25_MASTR

TX-COMU
Joined
Jun 16, 2013
Messages
4,644
Reaction score
1,158
Location
Texas
You can temporarily short the fuse to bypass (I'd put a fuse on the positive side of the cable lead) it to see if the radio powers up.
 

KYPLOW

Member
Joined
Mar 3, 2013
Messages
4
Reaction score
0
Location
West, Kentucky
That did it!! Hits repeater transmits well receives well. I removed the fuse and put a single strand of wire in its place to check it. All I have to do now is find a fuse lol. I can't thank you guys enough. I know you can buy these radios all day $50-100, but thanks to your all's knowledge I was able to put this one back in service!! Never tried making repairs on anything so tiny before, I'm feeling pretty accomplished. Thanks again. Matt
 

kruser

Well Known Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
5,096
Reaction score
1,439
Location
W St Louis Cnty, MO
That did it!! Hits repeater transmits well receives well. I removed the fuse and put a single strand of wire in its place to check it. All I have to do now is find a fuse lol. I can't thank you guys enough. I know you can buy these radios all day $50-100, but thanks to your all's knowledge I was able to put this one back in service!! Never tried making repairs on anything so tiny before, I'm feeling pretty accomplished. Thanks again. Matt

Glad it worked!

I'd definitely get a new fuse to replace the PICO fuse on the board and also get some inline fuse holders in that power cord!
 

N4GIX

Member
Premium Subscriber
Joined
May 27, 2015
Messages
2,124
Reaction score
386
Location
Hot Springs, AR
This is an excellent reminder to always check a power cable's polarity before connecting power! I recently ordered a replacement power cable for a Kenwood TK-880 I had bought, and when it arrived I noted immediately that the red and black leads were installed in the connector in reverse.

I notified the vendor to advise that they might wish to check their inventory to see if there were any more in stock like the one they sent me. Fortunately it was a trivial matter to reverse the polarity by extracting the pins and reinserting them in the plug correctly.
 

cmdrwill

Member
Joined
Mar 30, 2005
Messages
3,984
Reaction score
377
Location
So Cali
A very important lesson learned here: Always check the polarity of the power cable FIRST, and make sure you have a proper sized fuse in THE cable.

I believe I also mentioned abut using a small, 2 amp or less, fuse to test a unknown radio.
 
Status
Not open for further replies.
Top