I also have a fried zd3 on my boston acoustic mcs 95 Sub amp board. Do you know the radio Shack part number you used and did your amp power up? My Sub is not working. No power and no green light but my fuse is good. It did not blow out. I found Component ZD3 diode was fried - and not the D1 as I saw in the instructional post! Did you fix your unit?

Dean Pitts

• 126 Answers

SOURCE: Blows fuses

When you open up the radio and look at the component side (top of pc board), the diode you are looking for is D17. It is located basically in front of where the PA jack connected to the pc board. Just make sure when you solder the new one in place, observe the side that the grey band is on, which should be facing toward the point of the arrow pic.

You can pick the diodes up at most Radio shacks or online through www.partsexpress.com. I use Parts Express for all of my small electrical components and tools. They are very reasonable and very trustworthy. The diode you are wanting is called a Rectifier Diode. The part numbers range from 1N4001 and 1N4008. I use 1N4007 (the only one Parts Express stocks) and it works just fine. Here is a direct link to the page with this diode http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=1N4007
They are only .09 each. I hope you get your radio back in working order.

Dean Pitts
Rollin CBs
Mt. Vernon, TX

Posted on Jun 17, 2008

Dean Pitts

• 126 Answers

SOURCE: radio shack cb radio 21-1703

OK. I do not know the exact number for the diode off hand, because I don't have the same radio in front of me. On most cb radios, this diode is usually located on the component side of the pc board, close to where the positive lead solders to the board. Most of the time when it burns, it just becomes brittle.

If you do replace it on your own. The diode is called a rectifier diode, which you can pick up at radio shack or at partsexpress.com. The part number is between 1N4001 to 1N4008. When installing be sure to observe polarity, making sure that the side with the silver band is facing the direction of the arrow.

If I can help anymore, please don't hesitate to ask.

Dean Pitts
Rollin CBs
[email protected]

Posted on Jul 19, 2008

Louie Role

• 6966 Answers

SOURCE: Cobra 29 Ltd

Hi,

Appreciate the direct "Ask Me" again.

The initial posting would still hold true, best would be:

• remove TR18;
• replace 2SC2069 with 2SC1969; and
  
• adjust L12, 13 & 14.

Posted on Sep 08, 2008

SOURCE: Cb Radio blows the 15 amp fuse in the car when powered up

Look where the hook up wire goes into the circuit board. Find the protection diode.Round small black cynlinder with a silver band. cut the diode and run a continuity check across the positive and negative. If all checks out try to fire it up.15 amp fuse is way to high for that radio use 5- 7

Posted on Feb 10, 2009

SOURCE: help with cb radio

Diode number D11 is the audio limiter

Posted on Jan 30, 2010