DT-5302 Ammeter, ID of burned Q9 and Q10 components

[Ninjahopper]

Sorry if this is the wrong forum!

Hi guys, some 10+ years ago, i bought a DT-5302 Ammeter. Great thing. Worked like a charm.

One day, my dad came along and hooked it to my 220V mains. Lo and behold, a spark, smoke and a godawful smell. I tied my old man up to a lamp post and...yeah...long story short, we ended up opening up the meter together and we couldnt ID the parts that were burned. Could you guys lend us a hand? (we sent the pic to the manufacturer, nope, no replies, they probl. want more sales but its a shame throwing the meter away if all one has to do is to change a fuse and replace Q9 and Q10)

Best
Ninjahopper and his upset dad

 

[betwixt]

Poor Dad. Time to forgive and untie him I think.

Try wiping the top of the two transistors with a cloth and a little rubbing alcohol to remove the blast marks. There is a code marked on them, usually two or three letters or numbers. See if you can read them and let us know what they are.

Brian.

 

[Ninjahopper]

Thanks alot for the reply. It was a great idea to have a closer look at them. It says "L 6" on them.

 

[Ninjahopper]

Could it be the: 2SC1623-L6? If yes, forgive my ignorance, could you perhaps elaborate as to why one would need this transistor in exactly this configuration? What would the purpose of this transistor be you think?

 

[ZASto]

https://www.s-manuals.com/smd/l6

 

[betwixt]

It is difficult to tell why that part is used in that meter without knowing its schematic. There is nothing special about the 2SC1623, it is a general purpose part with many equivalents. Most likely it was the cheapest available at the time the meter was manufactured.

If you can't find the exact replacement, almost any SOT-23 packaged NPN transistor with a Vce rating of 50V or higher and an IC rating of 100mA or more will work equally well.

Brian.