Reading the values of SMD components.

[Mauried]

What do people use for this.
Tried magnifying glasses but most dont have enough magnification.
Main problem is the very small SMD resistors which look like about 50X
magnification is needed.
Trying to fix a backlight Inverter board which is mostly SMDs and cant
fit the board under a conventional microscope to read the values.
Need something like a simple hand held microscope, but all I can find
are USB based camera microscopes that cost hundreds of dollars.

 

[F Murtz]

What do people use for this.
Tried magnifying glasses but most dont have enough magnification.
Main problem is the very small SMD resistors which look like about 50X
magnification is needed.
Trying to fix a backlight Inverter board which is mostly SMDs and cant
fit the board under a conventional microscope to read the values.
Need something like a simple hand held microscope, but all I can find
are USB based camera microscopes that cost hundreds of dollars.

Type "hand held microscope" in ebay,loads of them .
I have got one I bought years ago at tandy or somewhere.

 

[Mauried]

http://www.dealextreme.com/details.dx/sku.42174

Thanks all.
Exactly what I need.

 

[F Murtz]

http://www.dealextreme.com/details.dx/sku.42174

Ebay can be 2, 3,4or5 dollars postage included.

 

[Grid Leak]

What do people use for this.
Tried magnifying glasses but most dont have enough magnification.
Main problem is the very small SMD resistors which look like about 50X
magnification is needed.
Trying to fix a backlight Inverter board which is mostly SMDs and cant
fit the board under a conventional microscope to read the values.
Need something like a simple hand held microscope, but all I can find
are USB based camera microscopes that cost hundreds of dollars.

Why bother - you probably won't be able to remove and replace the 801
resistor without damaging the multilayered board anyway.
Even if you do, the fault is probably with a 64 or more pin SMD processor
chip (maybe) which without the right rework equipment costing upward of $20K
cannot be replaced - the in-house marked chip probably not obtainable as
it's a proprietory component. So after maybe 10 hours and still not working,
at lets say a modest $80 per hour = $800, why not just through the damn
thing away and replace the board - better still, replace the whole damn
piece of equipment!

 

[Mauried]

Why bother - you probably won't be able to remove and replace the 801
resistor without damaging the multilayered board anyway.
Even if you do, the fault is probably with a 64 or more pin SMD processor
chip (maybe) which without the right rework equipment costing upward of $20K
cannot be replaced - the in-house marked chip probably not obtainable as
it's a proprietory component. So after maybe 10 hours and still not working,
at lets say a modest $80 per hour = $800, why not just through the damn
thing away and replace the board - better still, replace the whole damn
piece of equipment!

I know exactly whats wrong as the board in question has a known design
fault which causes a 1 Mohm smd resistor to go high over time.
The fix is to simply solder a normal 1/4 W 1 Mohm resistor in parallel
with the crook resistor, but the problem is that there are multiple
versions of the board all electrically the same but the physical
location of the resistor varies with the version.
Without being able to read the values Im just guessing.

 

[Trevor Wilson]

Why bother - you probably won't be able to remove and replace the 801
resistor without damaging the multilayered board anyway.
Even if you do, the fault is probably with a 64 or more pin SMD
processor chip (maybe) which without the right rework equipment
costing upward of $20K cannot be replaced

*Nonsense. Some patience, the right techniques, some practice and less than
$1,000.00 worth of equipment, it can be done. I've replaced more of the
suckers than I care to think about (I use a headband type magnifier, a Maggy
lamp, an Ersa iron with a 0.1mm tip + a desoldering station and some
SoderwickT - All up, less than a grand). It's a PITA and it requires great
care, but it can be done. I got an amp in in December. The owner was told it
was a write-off, since the daughter board was NLA. The chips (64 pin) were,
however. $24.00 each, a few hours work and the guy had is expensive amp
fully functional.

- the in-house marked chip

probably not obtainable as it's a proprietory component.

**Quite likely true.

So after

maybe 10 hours and still not working, at lets say a modest $80 per
hour = $800, why not just through the damn thing away and replace the
board - better still, replace the whole damn piece of equipment!

**Sometimes, that is not possible.

 

[SFD]

*Nonsense. Some patience, the right techniques, some practice and less
than $1,000.00 worth of equipment, it can be done. I've replaced more of
the suckers than I care to think about (I use a headband type magnifier, a
Maggy lamp, an Ersa iron with a 0.1mm tip + a desoldering station and some
SoderwickT - All up, less than a grand).

.... me too - only difference is I need a couple of Scotch's to settle the
0.1mm soldering iron!