DIYer Support Club :) **SMD noob**

[b0nz0beavis]

Just checking how any other DIYers are going?

When I decided to go the DIY route instead of waiting til early next year (I’m ~1080 on the waitlist) I had the following equipment and skills:

– 10 hours soldering
– 2 successful console mods (SNES Mini RGB, Saturn mod chip install)
– 2 x failed N64 RGB install (due to wrong scart cable)
– 1 x $30 soldering iron
– 0 smd experience

I now have:

– 16 hours soldering experience
– 1 successfully installed IC SMD ( yes, it took 6 hours, but I learned A LOT and I could do it in under 30 mins next time :-))
– 1 x USB flash programmer
– 1 x temperature controlled soldering station
– A better understanding of the importance of flux and thin solder wire
– I know how to properly use solder wick
– Proper desktop lighting with magnification
– A handheld 10x magnification thingy

Construction began yesterday and the main IC is installed. I expect the next ICs will go in tonight after work and hopefully all other components later in the week.

There were two things that delayed the install of the IC.

– My inexperience
– Using a forceful drag soldering technique that misaligned about 20 pins on one side of the IC. Fixing this was a nightmare of about 3-4 hours duration. The upside was developing a technique to desolder IC pins using the iron and some tweezers to heat and gently dislodged the pin from the incorrect pad.

Anyone else have stories, or am I the only idiot who jumped in the deep end with this as the first electronics project of any note? 🙂

[b0nz0beavis]

Going over yesterday’s work, found that I’ve broken one of the pads from the PCB. I remember hearing an odd sound yesterday and thought it was a leg snapping off the chip and being relieved that it wasn’t. Think I had the iron set too high. Tried to fix it but now the leg is snapped off.

Looks like I’ll need to but another barebones kit and EP4CE 15E22CBN.

Moral of the story; treat the IC legs with a feather touch and remember to turn the iron temp back down.

[dfwarden]

I also took the plunge on the DIY kits. I have slightly more soldering experience having also done the NESRGB mod, but certainly not with such small SMD components.

Out of curiosity, did you know about https://www.niksula.hut.fi/~mhiienka/ossc/diy-v1.5/assembly_tips.txt? I’ve found his recommendation for 300C and connecting opposite legs on the ICs first (to achieve good alignment) before drag soldering the other 2 rows to be excellent advice. I also struggled to remove solder from IC pins and my side to side motion resulted in more than one bent pin that was tedious to fix. I found it was easier to control the flow of solder to the legs by using a very fine tip and only putting enough solder on the tip to go a 4-6 pins at a time. Maybe with more practice I could have used a larger tip and done the whole row in one drag like he recommends.

I was able to get the board fully assembled, but discovered that all but one of my voltage regulators have a pin with an incorrect connection to ground. Hopefully I just have a small bridge on the ICs that needs to be cleaned up as I’m still very new to the art of diagnosing malfunctioning circuits.

Best of luck with your second attempt.

[b0nz0beavis]

Thanks mate. Good luck with the diagnostic work. I’m kinda daunted by that too but am guessing it has to be easier than soldering smd by hand…?

Been following Marqs’ workflow to the letter so far. The side I wrecked was the third side – I got carried away after learning how to use solder braid effectively and also completing the second side much quicker than the first. Totally rushed the third like a supernoob bahaha/whoops.

Just got email confirmation that Bucko has posted the replacement barebones kit to me already, so fingers are crossed it arrives before the weekend.

[BuckoA51]

If you contact me directly I can sell PCBs without cases too, should that be necessary.

[b0nz0beavis]

Thanks Bucko. The store said there was only one barebones kit left and I didn’t want to leave it to chance, so I pounced.

I don’t mind having a spare case, might come in handy for replacement or maybe I’ll build another OSSC at some stage 🙂

[b0nz0beavis]

Dfwarden, did you end up tracking down the short to ground?

I finished my second assembly attempt a few days ago. Didn’t have any shorts, just 1 resistor in the wrong spot (which I discovered by accident) and a missing cap.

After getting some help from Marqs I found the missing cap and now AV1 works flawlessly.

[dfwarden]

Apologies for the late reply… I did figure out that I had a bridge somewhere in the left row of pins on the TVP7002 (presuming the LCD side is “top”). I more or less destroyed all 3 chips tracking that down since I don’t have a clean way of removing them. (I might need to bite the bullet and invest in hot air.)

I got a fresh board and my second attempt was better in that all the voltage regulators are connected correctly and outputting the correct voltage, but I must have a problem somewhere else because the LEDs don’t turn on and the LCD backlight is very dim. I saw marqs gave some good suggestions on “LIGHTS ARE ON, BUT NOBODY’S HOME” that I am going to investigate before I start a new topic asking for help.

[b0nz0beavis]

What sort of magnification and lighting are you using? With good lighting and 10x magnification (I use one of those 10x mag thingies with the handle and LED lights built in, soz I don’t know the name) you should be able to easily tell if you have a bridge between pins.

Also, I found that 3mm solder wick works great at removing excess solder. And, this might be obvious and you already know, but adding more solder and then removing with solder wick is a good way to remove those tiny and stubborn bridges that won’t come away with solder alone. The key to solder wick is to place the wick, apply heat and wait for a puff of smoke before dragging it away IC. Surface tension should take care of the rest. Oh, and flux. I used the type that requires cleaning, like Marqs recommends in his guide. I used way to much on my first board cos that was what various YouTubers did, but it turns out that using just enough to smear a thin layer over the PCB pads gave a much better result.

But, maybe your problem is something else. Given you’ve already been pretty diligent in checking the ICs for bridges….

How is your equipment in general? I spent more than the cost of the DIY kit itself to make sure I had decent enough soldering station, lighting, magnification, flux, 0.5mm solder wire, etc. Figured that I could use it on other projects in future and that I wasn’t just going way OTT with this retro gaming hobing obsession thing 🙂 again… 😀

[dfwarden]

My equipment is probably not as good as yours. I’ve got a decent iron (Hakko fx-888) with a fine tip for the SMD bits but I haven’t had great success with my MG Chemicals wick or SRA #80 flux pen. Perhaps I just need to improve my technique – I’m going to try to give your wick advice a try. Probably the weakest link in my chain is I only have up to 4x magnification, and even through that lens you can only on a small area.

This project also motivated me to improve my equipment. I worked my way through various console RGB mods with an entry level iron and no magnification, lighting, or flux. What a difference having decent gear makes!

[b0nz0beavis]

My lamp has 3x and 6x. These are fine for soldering and using solder wick (it’s too hard / impossible to spot the smoke I mentioned with the naked eye). The 10x self-lit thing I have was $30 Aussie, but cheaper ones should be available. You should definitely check out this option as 6x wasn’t enough for me to determine if pins were bridged.

You should search for solder wick for SMD ICs on YouTube. It was there that I learned about the puff of smoke – the puff means it time to wipe off th solder and helps avoid overheating the chip and pins. Also make sure to keep the tip temp around 300-310. I wrecked an IC and a pad on my first DIY attempt cos I left it at 340 when de-soldering.

[CoachMcGuirk]

I’m just about to pounce on one of the in-stock Barebones DIY kits. Pretty excited to dive in, and I have all the parts sourced, but the only thing stopping me is the S25FL216K Flash Memory firmware, which I’m planning to order from Mouser if that matters. Now, I don’t really have much experience with chip firmware, so apologies in advance if I’m missing something very obvious, but I’ve searched everywhere and haven’t really been able to find a solution, but I saw that BonzoBits had a question about it in the barebones kit comments, so he must have been down this same path.

So, I was hoping one of you brilliant DIYers could tell me how you managed to flash the S25FL216K in your assemblies? Did you get it pre-programmed in the Advanced DIY kit? Did you track down a NAND/NOR programmer to buy or borrow? Does it just get programmed with the initial FPGA firmware flash via JTAG after the OSSC is assembled (I’m hoping it’s as easy as this)? Or is there something else I’m missing?

[b0nz0beavis]

G’day mate. Good luck with the build!

It should just be a matter of connecting the flash programmer via JTAG to the completed assembly and following the guide that’s linked in the wiki and in the thread I started.

There aren’t any specific steps for the chip you referred to – just follow the wiki and all takes care of itself. The only problem I had with flashing the firmware was that it took a few tries to get the flasher drivers correctly loaded, but that was specific to my setup and fixed easily.

[CoachMcGuirk]

Fantastic! Thanks for the reply BonzoBits, and thanks for the good luck! I was hoping that I would only need to flash everything once with the JTAG connection, so this is great news. I guess I got confused by the pre-programmed chips in the parts list and I over complicated everything in my mind. Looks like it’s time to order some parts…thanks again!

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