Print

[ferrari_rulz_02]

yeah i know what you mean.

this could be right you know...though i hope its not

but you may never know.

atleast we know how to fix this one now.

[PimpleX]

Nice one Dallas. Do you think two 2A trannies (the v1.6 mobo transistor replacements) would work the same, ...as I have a few of them here already?

I'm waiting for a 1mm tip for my iron before I try this again though LOL

Cheers,

PimpleX

[Dallas186]

sorry for the late response, are you sure it's 2A? not doubting you for one second but 2A is a MMBT3906WT1 which is not a dual transistor, the data sheet shows only 3 pins for this package (SOT323)

sorry but could you check that code again, there should be 3 letters, the first 2 are the identifier and the last the manufacturing month.

cheers m8.

Rich

[Dallas186]

you will get on better with the small tip, assuming that 1mm is smaller than you originally had..lol.

I assume that you have a reasonable wattage iron, if i had a quid for everytime i've read or been told that a low wattage iron is best than i could have retired years ago!! higher wattage is better especially for SMT components, solder quick get off fast, linger longer and blow the component even more so on IC's.

though to be fair i do have the benefit of having a SMT 'pincer' type iron.

Rich

[PimpleX]

No, I meant....you used 2 x transistors to replace the dual transistor as an experiment and it worked (probably because they were near spec) ,...so I'm thinking I can do the same using 2 X 2A (the 2T v 1.6 mobo transistor replacement) instead

2A / 2T looks like this http://www.xboxrepairguide.com/troubleshoot/index.php?episode=32

I say this as the parts are easier to source

P.S I DO NOT know what I am doing, i am a total (all be it enthusiastic) amature LOL

Cheers,

PimpleX

[ferrari_rulz_02]

yeah id say they work. as long as they are of teh same type (NPN i think), and the pinouts are the same.

definitley worth a shot if they are much easier to find

[Dallas186]

sorry guys, these 2A trannys will NOT replace the MA! even by putting 2 of them on, the 2A is a PNP transistor.

spec sheet 2A (MMBT3906)

PimpleX, As i said before just PM me your address and i'll mail you a few.

Rich

[fr_dr]

So what about 2 x 2n3904? It is a NPN, so i think it should work but i'm not shure about the specs. And does anyone know what is the pinout for these transistor?

[PimpleX]

OK I got you, just read up on PNP and NPN so it wouldn't work with the 2As as the current flow goes the wrong way,...damn shame as apart from the PNP part the specs are near identical LOL and I was just heating up the iron to stick em on! Keen I am see!

I'll await my 1mm tip and try again with the correct chip, other alternatives would be a very welcome find though if anyone can work some out, especially so if they are a bit bigger and easier to handle

Cheers,

PimpleX

[thedominor]

I'm really glad to hear progress has been made, thanks Dallas and Pimple especially for doing so much testing.  I think I have some 3904s in my 'kit,' so I might bust out my old mobo and see if this works.  It sounds like maybe I should get a small tip though, and I'm glad to hear an explanation of a soldering iron that makes sense; in my own words, hotter irons melt that shit faster = less waiting and uncertainty.  Dallas, do you think you could do some ms paint over that pic you posted with the two Ts, to show which is EBC?  I know which was the board is facing because of the traces.  That would be appreciated so i don't have to figure it out myself  

[Dallas186]

QUOTE(fr_dr @ Oct 25 2005, 03:12 PM)

So what about 2 x 2n3904? It is a NPN, so i think it should work but i'm not shure about the specs. And does anyone know what is the pinout for these transistor?

spec sheet for a 2N3904 here

i assume your'e going to try putting 2 seperate tranny's on like i did in a post above though it was only a test to prove a point. make sure that you download the spec sheet for the MBT3904DW1T1 first from  here to understand the pinouts.

hoipe that helps you, if not just post back.

Rich

[PimpleX]

Not sure about the specs on those 3904s, but there's quite a few 1AM trannies on my "highly knackered scavenge for parts only" XBOX mobo that I could scavenge and use and I'm thinking they are the 3904s in SOT23 package right?. (same shape as the 2A trannie)

I just think the 3904DW1T route will be too hard a fix for "average jo" out there (which includes me) and would like to find a method that more people can actually accomplish..... make sense? So working with a slightly larger easier to handle IC or two and despite it taking much longer to do and it not looking so neat will actually help many more people to do this fix (once we confirm it works on several boards) This is why I'm trying to make it more accessable really.

I've already tried it with the tiny 3904DW1T1 and the screw up ratio WILL be very high indeed and many will be unable to do it at all!! So, I'm searching for an easier method for more of the masses.

Run with me on this one.... can we find a commonly available 3904DW1T1 dual transistor replacement in a slightly larger package?

Cheers,

PimpleX

[ferrari_rulz_02]

yeah thanks guys for all the hard work you have been doing.

ill have a bit of a search around the local shops, see if i can find something close to what were looking for.

[fr_dr]

So, does anyone has been succeful in changing this dual transistor (i mean other then Dallas)?? Does it solve the problem??

[ferrari_rulz_02]

ive a bit of a look around. some of the shops the specialise in electronic components have them (in australia - use wes components).