Transitor/ESR tester dead

[keeney123]

Re: Transitor/ESR tester dead

This 78L05 reg (IC2 on my board) reads 3.2K ohms between Gnd and Out leads. It's not shorted. I've got a 2 ohm short downstream on the board.

When you say downstream does that mean going to the 5 Vcc to the IC chip? If that is the case can you not lift resistors to determine where it is?

[stj]

Re: Transitor/ESR tester dead

I'll try making an aluminium shield over the board.

i keep the covers from old tuners for that.

[SteveNielsen]

Re: Transitor/ESR tester dead

Hmm, I've got a copper RF shield from an old Mac backplane. If I cut off the part with holes and flatten it out it might work too. OR get soldered to the board... I think I'll pass on trying that and going with the Al foil unless I dig up something better... Alright - I've got a nice Al pie pan.

[stj]

Re: Transitor/ESR tester dead

if the chip is bad then:
http://www.ebay.co.uk/itm/141666259867

and:
http://www.ebay.co.uk/itm/261574745774

[keeney123]

Re: Transitor/ESR tester dead

Stj I do not think the schematic matches up with the board as the large IC is 32 pins and your schematic is 28 pins. The pin out on the 32 pin makes pin 4 the VCC.

[stj]

Re: Transitor/ESR tester dead

there are many schematics because it's an open evolving design and the dil chips and smd chips have different pincount.

[vinceroger69]

Re: Transitor/ESR tester dead

this has some good info too
http://www.cwtd.org/May7.html

[SteveNielsen]

Re: Transitor/ESR tester dead

Without the chip there is 1053 ohms from Gnd to Out pads where IC2 reg was, so the 2 ohm short is in the chip.

Al foil in 4 layers for a heat shield worked perfectly. The chip came off sliding sideways a bit so I cleaned up the solder pads for it with wick and iron and no solder bridges or damaged pads. This is a first for me; the first smd microchip of this type I have ever tried to remove! Yay!

[stj]

Re: Transitor/ESR tester dead

good,
so if you jump the regulator you should see 5v - just to be sure.

[SteveNielsen]

Re: Transitor/ESR tester dead

With or without display attached?

[stj]

Re: Transitor/ESR tester dead

either - just to check the regulator wasnt damaged.

[SteveNielsen]

Re: Transitor/ESR tester dead

Ok, w/o display regulator has 4.96v on Out. 9.06v on In.

[vinceroger69]

Re: Transitor/ESR tester dead

is the software easy to get? if you go for the ebay chip/programmer.

[SteveNielsen]

Re: Transitor/ESR tester dead

My tester doesn't have the USB port and circuitry.

[stj]

Re: Transitor/ESR tester dead

the programming header can be fitted - it's the 2x5 set of holes.

software is easy, you download the source,
set the options for the type of display etc,
then make the hex with winAVR compiler.

[vinceroger69]

Re: Transitor/ESR tester dead

no mine dosnt either ive just found this though
http://www.mikrocontroller.net/svnbr...ster/Software/
http://www.mikrocontroller.net/topic/248078

[stj]

Re: Transitor/ESR tester dead

interesting - gonna take a while to look through that.

[vinceroger69]

Re: Transitor/ESR tester dead

interesting - gonna take a while to look through that.

just added another link ive found not sure if its for these testers though

[stj]

Re: Transitor/ESR tester dead

oh yes - cutting edge version!

[keeney123]

Re: Transitor/ESR tester dead

Without the chip there is 1053 ohms from Gnd to Out pads where IC2 reg was, so the 2 ohm short is in the chip.

Al foil in 4 layers for a heat shield worked perfectly. The chip came off sliding sideways a bit so I cleaned up the solder pads for it with wick and iron and no solder bridges or damaged pads. This is a first for me; the first smd microchip of this type I have ever tried to remove! Yay!

All right victory!