Diode replacement

**ss30** · 17th August 2014

Originally Posted by cosmicma

it certainly would but they tend to short out unless they fry

looking a bit closer at the board it looks like the left leg of the voltage regulator has gone dry ( dry joint ) which might need a touch with a bit of solder

did you check the diode with a meter ?

Thanks, I will resolder the joint when the replacement diode(or should I say 100 diodes) arrive.

Yes I did check it with a digital multimeter with a diode check function

**plug1** · 18th August 2014

Tbh I think the doid has just failed , as said they don't often go oc if another failed component or reverse polarity ,they usually short .

**ss30** · 21st August 2014

Just replaced the copper wire with a new M7 Rectifier Diode and now it wont work............

**Northernbloke** · 21st August 2014

Silly question but Did you put the diode the correct way round? It's an easy mistake to make

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**tronads** · 21st August 2014

It could also have instantly blown again.

**supraman54** · 21st August 2014

Maybe substitute an ammeter for the diode and see what current it's passing? see if that exceeds the rated current for am M7?
I understand they are rated at 1amp max output but are surge rated at 30 amps.. that's mighty hefty.

supe

Features
Diffused Junction
High Current Capability and Low Forward Voltage Drop
Surge Overload Rating to 30A Peak

**plug1** · 21st August 2014

You should have left it shorted out lol .

**ss30** · 22nd August 2014

I have just checked some of the diodes(as I got 50 of them in a strip) and with the multimeter set to diode test I don't get a positive reading checking either way round!

This is what I bought.

**plug1** · 22nd August 2014

Set it ohms it should be short one way and OC the other . Are you sure you put it in the correct way round ?

**ss30** · 22nd August 2014

Originally Posted by plug1

Set it ohms it should be short one way and OC the other . Are you sure you put it in the correct way round ?

On ohms I get a reading one way and not the other.

I tried 2, the first one the way round I thought it should be, the second one the other way. I tried 2 just in case I killed it putting in on the wrong way round.

**plug1** · 22nd August 2014

That's what you should get mate , does it still work if you short it out ?

**ss30** · 22nd August 2014

Yes.

Edit:- Just installed the diode that I checked the ohms of and it works, I dont know if the first diode I installed the right way round was a dud or not but it's working now.

Thanks for all of your help especially plug1.

Paul