FINDING PARTS: A step-by-step guide.

I often get asked, “what part is this?!” “how can I find it?”

The following guide was written by Thomas Ng, for console repair tips please join the facebook group Game Console Repair Legion

Get a CLEAR picture of the top of the part. This includes:

all of the text on top
any orientation marks
logos
how it generally connects around the board.
**Even better: **identify VCC rails, its voltage, and GND pins, silk screen marks.

**Look at the vendor website **for the part number if you can identify the logo (a list of semiconductor logos is here (Certainly not complete, but it helps for the newbie): http://rtellason.com/semiconductorlogos.html
For IC’s, many times there are multiple lines:

xxxxx
yyyy
zzzz

More likely than not, the part number is the first line. The second and third lines are lot codes/date codes/COO (country of origin) codes.

**GOOGLE search **the part number (if there is one)
**Identify the case packaging. ** There are fairly standard case packages for devices. They maybe through hole, surface mount (SMT, SMD), or a combination of both. See first image below, certainly not a complete list either, but it may get you started.
**MEASURE the part dimensions **(x, y) and pin pitch (center to center spacing per pin. Use a **millimeter ruler **next to the part in your pictures, or a set of calipers. Images without reference dimensions are useless.
**Are there hints as to what this part does? **Is it a diode? Power supply? Cap? etc. If you can identify the general function of the part, it can get you some more information.
If you find a part that looks “close” – does the datasheet show the pinout? Does it look like VCC/GND pins are the same as the physical part in hand? Do the other signals look right with caps, resistors, etc hanging off the same net?

Does the datasheet have a marking area that align with the part you see?

Example #1 (second picture)

What do you see here?
I see:

silk screen stating “ZD38” — ZD is a zener diode.
This is a SMT device.
It has an orientation marker on one side.
It has the letters “K2” and “2” and a “2” stacked on the right
This looks like (to me anyway, an SOD package) (SOD == small outline diode)
measured, the part is approximately ~1.5 mm x ~2.6 mm

This is what I searched for on Google: “Zener diode K2 SOD“

I look through the results and look on vendor websites (vishay, diodes inc, etc) and distributors (digikey, mouser). Even website hits from AliExpress/eBay may be useful.

I see result hints this may be a “SOD-123” package, or a “SOD-123-2” package type from jameco, mouser, eBay.

I see one result showing “MMSZ5252B SOD123 K2” on AliExpress <– interesting.

So lets follow that lead and look for MMSZ5252. (We’ll omit the suffix for now) I see a datasheet from diodes incorporated (https://www.diodes.com/assets/Datasheets/ds18010.pdf)

Scroll down to the parts table and find “K2” –> looks like this is a:

Diodes Inc –> Zener diode
case type is a SOD-123
marking is a K2
This is a 24V zener (Vz)
Test current is 5.2A,
Reverse leakage current (IR) @ a specific test voltage (VR) is 1uA at 18V.
The part body is 1.4~1.7mm x 2.55~2.85 mm (includes min/max tolerances)

If I search for different vendors … i also see Vishay is on the Google results. Lets look at their MMSZ5252 datasheet (https://www.vishay.com/docs/85774/mmsz5225.pdf) and cross reference.