Need helps

[cossy350]

Hi I need some help

I have a snap on QBT 200 it is a little handheld machine with 4 double A batteries which test 12 volt car batteries to tell you whether they're good or bad I was using it today and a big puff of smoke came out of it I need help in identifying the parts that have gone I have taken pictures and in the pictures you can see the part that is gone and next to it seems to be the exactly the same part but I'm not sure what it is or if it is different in any way and there is a glass tube which has broke as well

[PoBoySolar]

It is likely the same part, a very low ohm resistor.  It looks like this puts a momentary load on the battery in the nanoseconds and the voltage is measured.  Could probably be replaced with a four inch piece of wire.  If I had it in my hands to examine I could tell better.  It is yours to blow up further.  Before doing that I would want to test the FET it is connected to for shorts.  Measure one pin to another.  Generally the two outside pins, the gate, short when a FET goes bad.  The company probably won't tell you the part and often  a factory repair is not economical.  That is when it might be a good idea to experiment.  Did you hook this up backwards?

[cossy350]

I didn't connect it backwards it just popped as I press the button to test the battery it does momentarily load on the battery and then it gives you the results one of the fet are bad what is the little glass tube called as that is cracked also

[cossy350]

Which number on the fet do I need so I can replace them

This is what's written on them
IRFP064
IR
2Y2H 9751

[SeanB]

IRFP064 is the part number,

http://www.infineon.com/dgdl/irfp064n.pdf?fileId=5546d462533600a4015356283b1d1fc8

Datasheet here, and the part is available from Mouser for a reasonable price.

http://eu.mouser.com/ProductDetail/Infineon-IR/IRFP064NPBF/?qs=sGAEpiMZZMshyDBzk1%2fWi5%252bqVgN3%252bWS8G8awMUgotiM%3d

[cossy350]

Thanks a lot for that information

Also if you could help me what is the part called the little glass tube with the two rods in the middle see it in the picture next to the burnt out components

I also need to order the burnt out components this is written on the one beside it

DALE WSR-2
.05 OHM 1X
9733

Any information would be great helpful and thanks a lot againw

[PoBoySolar]

The little glass tube is a gas discharge tube for any inductive high voltage spikes that might develop.  Pretty surprised it is there instead of s MOV.  It didn't look damaged.  Could be only a simple neon lamp.

[cossy350]

There is a crack on the side of the glass where would I get one of them from

[SeanB]

You can use any neon indicator lamp as a source, or just order one with the mosfet and resistor. In the UK that would be Farnell, RS and in the USA Mouser, E14, digikey as examples.

The neon lamp is used as a low cost voltage clamp, it is also possible to replace with a Varistor or a Transorb diode, but the neon lamp in this use is fine and cheap so that is why it was used.

[cossy350]

thanks alot

[cossy350]

hi looking at the dale wsr-2 but dont not which one to get
it is 11mm by 7mm

http://www.mouser.ie/Passive-Components/Resistors/Current-Sense-Resistors/Current-Sense-Resistors-SMD/_/N-7fjcg?P=1z0x7b2Z1z0wljo&Keyword=dale+wsr-2&FS=True

[cossy350]

And also where would I get the neon indicator lamps from as the ones I can see online do not match the same size as the ones I have does size matter in this case they measure 7 mil by 17 Mill and I can see there is different colours does the colour matter as well

[SeanB]

The WSR2R0500FEA will fit, just buy 2 so you have a spare one for next time.

The neon lamp is not critical, any red neon lamp with wire ends will fit there. 606-A1C is a good enough replacement for it.

[cossy350]

thanks alot for all your hlpe