SCSI corruption & SCSI patch

[wongck]

you must use tweezers {beeding tweezers and a stong pair of mag glass headset or an eye loop}
and a 17 watt pencil iron wet all contacts with fresh solder first
then solder the resistors .....

tweezers... check.
mag glass headset.... nope
17 watt iron..... I don't even want to tell you the watt of my soldering iron... it's that bad

I think those resistor are totally fried.... back to the drawing board.

[wongck]

then before all
take a photo of the resistor area using macro mode and post
and dont touch it further!!!

wish I read your post before I'm on it again....
this time I solder back those fat wires from the scsi-clock patch to where it was.
And phew.... the fuji logo came on, hdd spins and boots into Mint....
Of course that scsi issue is still there... but it's better than having a busted falc.

[wongck]

Yes, I think you have done what I keep doing... Jumped too quickly into it.

thought it would be a simple job... just 2 resistors....

Take your time, you probably havent done any real dammage

Yes, it's working again. once I solder back the mod wires.

The way to solder resistors, is, for me, to "Tin" or melt a tiny little dot of solder onto the place where you want to stick the resistor, and also to melt a bit of solder on the resistor too!
Its a balance of heating up the resistor to a temperature thats hot enough to melt the solder once you touch the solder onto it, and not hot enough to kill the resistor ( or any other component )

But anyway, you heat up the part with the iron and then touch it with the solder wire... If everythign is good, the wire should melt a tiny dot there.

Thanks for the pointers. I will look this up when I am doing it again.

[wongck]

I have used standard 33r resistors instead of SMD ones ( Surface mount or small ones )
http://www.fatrakoon.co.uk/atari/temppix/wong-3.jpg

I love the way these are done....
How did you do them?
I may attempt this !!
Sure beat trying to solder small components...

[FatRakoon]

Erm, well, I am no expert in soldering or Electronics, however, many years ago, I did plenty of silly little projects like flashing lights and such like, so, much of it is fairly straight forward.

But...

I know how I felt when doing this fix.

I had not touched a soldering iron for about 12 years, and now all of a sudden, I had to not only clean up a mess caused by the installation of one Patch, but I had to also change it to another patch and then revert it to stock.

So, I know its a little daunting.

I could I suppose do a video perhaps of how to "TIN" a resistor and a circuit board ( The Falcon Mobo ) ready to put the Resistor in place if you want?

I could upload it to YOUTUBE?

Do you want me to do that for you?

It might help a bit?

[wongck]

Thanks. But there no need for a video. Too imposing on you.

I just can't figure how you got them to stand up like that while there is no holes to hold them.
I am thinking, may be you pre-bend them to form "legs" to exactly fit the pads.
Carefully "level" the legs so they are flat against the pad (the wires are round).

It must be some nifty prep work done on them.

[FatRakoon]

Thanks. But there no need for a video. Too imposing on you.

No, its not.
If you need help, and I can help, then its not imposing at all. Its just basic common decency.

I just can't figure how you got them to stand up like that while there is no holes to hold them.
I am thinking, may be you pre-bend them to form "legs" to exactly fit the pads.
Carefully "level" the legs so they are flat against the pad (the wires are round).

Well, yes, I shape the resistor to the shape I want it to be in, the shorter leg is bent straight off the resistor and cut so its only about 3mm long, I then "TIN" the leg, not too close to the resistor and as quickly as I can before any damage can happen.

The second leg bends straight over the resistor and down to meet the shorter leg.
I then "TIN" the very tip of this leg.

I then solder the flat part of the shorter leg, to the falcon motherboard, while holding the resistor upright.

Its possible to do this with your hand but the heat might hit you, so I used a pair of very thin long nosed pliers.

I held it there for a second to make sure that the solder had hardened enough, and I then simply pushed the longer leg onto its contact and touched the joint with the tip of the iron and it melted the solder and made a good contact.

The important bit really, is the "TINNING" as I have said before... Once you have that, its easy.

Care fully warm up the board where you want the resistor to go, and put some good solder there and a drop will melt and stick to the board properly.

If ir does not stick, or the board is not hot enough, you will just make a ball of solder and this is just not good enough, and it means that you did not heat the board up enough. If the board is hot enough then the solder will melt and spread out nicely.

Do the same on the resistor... Get it nice and hot and when you touch the solder onto it, teh solder should spread nicely instead of balling up.

But remember... The board and the resistor dont like too much heat so you have to use caution and common sense.

Also, when I say apply the solder, I do mean to apply it right next to the soldering iron, not away from it.

It must be some nifty prep work done on them.

Erm, yes, thats exactly what I do!!! - What did you expect?

[wongck]

I will head out to the shop to get some 33R resistor next few days.

[simbo]

hi ck

please buy this http://cgi.ebay.co.uk/HIGH-QUALITY-ILLU ... 2eaa470f13


BEFORE working on smd

i am 42 years old and i find it hard to work clear eye'd on smd

and i have only 20/10 vision now {last test 2009}
i was offered a pilot licence signiture by the optition as i was worried about near sight depletion
this is normal with age...

but my near sight is now much worse than maybe even when i was ~30

i used to be able to solder by easy eye ham radio 20 by 20 mil 144 pin processors
when i was 20< now maybe plcc is easy by eye only
hidef for me now is this product

..

do not do work unless
1} you have all parts to hand
2} you have all needed tools to be comfortable to work to hand

there is no 3


tempreture needed to solder is 260deg +
for 60/40 lead tin solder

so use 260+17 watts {1 deg per watt} so 277 deg

or make sure you use a 17watt or less iron on smd with a pencil tip fitted

be in no dought that your falcon probably has a poor clock to the dma cpu or fpu
clk 1 2 3
most often the dma
the 0R to the right of the 33R group should be i also agree a 33R body type thru hole
and termination resistor at the dma
and upgrade the clock drivers to bc547C type however there legs need to fit


nothing more

oh and as your broken falcon may have had a ct63 etc
dont forget to fit the needed jumper {a no brainer sorry... }


tip

if you add a fine pencil tip to a say 25watt iron
and you work well with it

to reduce the iron to 25/2 +0.404 so ~17 watts

add a diode like

live>>> ---->|---- iron live............|=diode band one end {cathode}
neutral ----------- iron neutral

so a diode say 1N5407 is a good choice
will reduce the power of the iron by 0.4140738 over total of 1
just turn the iron down...!

20/20 vision means that your leading eye is 20 times better at focus than your non leading eye

so 20/10 too me and i am right handed means my right eye is 20 times better than my left eye
and the left is 10 X better than average...

this is no surpise to me as i had damage to my left eye as a child and black liqid flowed down my cheek
{vbad and haunts me now!!}
however 10 X better than average for a damaged eye is aok for me
except near sight

20X10 is 20 X a standard eye this is good.... but near sight isnt guaranteed
for sure...

[wongck]

hi ck

please buy this http://cgi.ebay.co.uk/HIGH-QUALITY-ILLU ... 2eaa470f13

..

Thanks... I see if I can find one at the local electronics mart.