zzattack

Jig idea: generic stencil for 0.76mm balls at 1.27mm pitch, with unused pads masked off using kapton tape. Since the interposer boards are 1.6mm tick, I surrounded it with PCBs of identical thickness, secured onto an ABS sheet with (thin) double-sided tape. The interposer squeezes firmly in between the surrounding boards. A few overlaying strips of kapton briefly elevate the stencil. This gives the stencil some vertical clearance for the balls to fall through, and ensures the flux on the board doesn't touch the stencil. Regardless, I highly recommend cleaning off the stencil after every board for the best results. If balls don't fall through on the next one, you should've cleaned it. After pouring on the balls, I use a very soft ESD brush to spread the balls. They balls are not encaged so I used a very light touch, or else I'd be finding solder balls all over the place for months. With the balls placed, lift the stencil and manually repair any imperfections. You can see the bottom-left ball didn't make it. After having worked on some 0.2mm BGA stuff recently (not fun), manually placing 0.76mm balls is no longer any issue, even for pads that have 8 surrounding ones. On to the hotplate for attaching them. I highly prefer IR over hot air because the balls don't move. With hot air, if you have just the tiniest bit of excess flux, balls start drifting freely. Repeat... and after about 2 hours the work came to an end. Surely there's better ways to spend your Saturday but ultimately, it's good to have it done. Not perfect, but with a small (say airbrush) compressor and simple paste dispenser you can place drips very quickly, with reasonable accuracy, and reasonably similar amounts of paste. So I'd say it's fine.

Tomorrow I'll add some pictures. I've prepared a jig for reballing the 9 interposers I still have, since placing the balls by hand just once, however humbling the experience may be, just isn't for me. For that I used a regular stencil with the unused pads masked using kapton tape. Pics will clarify. I'll also add some info for the paste dispenser that I used, although I prefer having a stencil made instead.

Picked up one defective xbox for recapping but noticed it still did not turn on even with fresh caps. The clock cap had leaked and taken along some traces with it. Luckily superficial, so easy to spot and fix: 1) Assessment of the damage. Not too bad. 2) Scraping away all the crap to expose bare copper; treat it like a contaminant and get some clean margins. 3) Tin the exposed copper to prevent oxidization. Very minor trace interruptions can be bridged by dragging solder over them. 4) The larger interruptions require being bridged with some wire. I found AWG40 to match the existing trace width. 5) For rigidity and insulation, applied some conformal coating. 6) Result after curing. Now she powers up nicely Next!

It's taken about a decade of time and a year's income to equip it to the point where it is now, and it allows me to do a whole lot of stuff from home. A lot of it is luxury though, making things easier or providing additional room for fuckups before turning disastrous. I've been able to take a huge variety of repair jobs, which in turn funded acquisition of more gear to take on additional repair jobs. A nice circle indeed. That said, this particular kind of job in my opinion does require a BGA station, but an Achi/Honton/Scotle will do perfectly fine. I did probably about 200 BGA replacements before I exchanged my IR6000 for what I use now. Getting a stencil is probably better than using solder paste from a syringe, so if you don't have a paste dispenser, that's what I'd suggest. Aside from that, I don't think the requirements are too demanding for this job. Some good flux maybe The shipping fees will feel like a scam for sure but I think we can be creative on 20 year old stuff when it comes to VAT/customs

Yeah... somewhere in between those two numbers indeed. Purchased as payment for some freelance work in an income tax optimizing attempt Can do. Would be one console for me to hunt. Feel free to contact in PM to arrange that. There's no list I think, and I have enough 1.4GHz's to cover the 10 for which I have components, so I'm not sure this will work out.

Had less time than anticipated tonight, but I did manage to pickup the replacement electrolytic caps from Farnell at the pickup point. All the 1.6's are recapped, which as suspected resurrected the 2 dead ones as well. So, these have clean shells, boards + PSU's gone through ultrasonic cleaning, recapped, fresh thermal paste, I restored the LPC with a QSB (but did not install any modchip). I'm ready to part with them, and I'll be hunting to find non-1.6's to replace them in the coming days. Tomorrow I hope to get the remaining ones recapped and TSOP'd, plus maybe RAM upgrade on one or two of them. It's about a 50/50 chance I'll have 2 more Tualatins on Saturday, so fingers crossed we may get to complete two boxes entirely. I've dumped some pictures here for now on imgur: https://imgur.com/a/grMufPW. The forum itself feels very restrictive in regards to maximum and combined filesizes.

I just made some offers on a few CPUs on eBay yeah. One of the sellers said "I have more" and I purchased 8 off of him. In total I will have 11, assuming at least one's a dud. I've got a WDS-620 station.

Regarding progress, yesterday I started on the pile of 10 by softmodding them/nulling HDD keys, primarily so that I can throw all disks on a pile without having to worry about keeping pairs. All motherboards and PSU's have received ultrasonic cleaning, while the enclosures took a bath to get rid of dust and potential smells. As far as I could tell, none of them came from nicotine using owners, but 3 or 4 likely had pets, so I'm happy those smells are replaced with a fresh scent. While the enclosures were getting bathed, I set out to remove some clock capacitors, clean up potential leaks from said supercaps, and overwrite the stock BIOS on the TSOP memory. Sadly, 4 out of 10 are 1.6's so they won't have a future with me. I don't think it makes sense to go all-in with a CPU swap if you're inevitably going to remain stuck on 64MB RAM with an Xcalibur encoder. I'll be patching these up with new caps, new thermal paste, and then I'll probably dump them at a loss. From the remaining 6, one isn't powering on (likely due to bulged caps) and 2 more do work despite having bulged caps. New caps were ordered yesterday, so today I will be replacing the electrolytics on each of the 10 boards. Time permitting, the 6 non 1.6 revision boards will get a TSOP flash, and then I can start with the RAM upgrades over the weekend. When those are done, I can take a (long) break until the Tualatin CPUs arrive from China. Meanwhile I also arranged for an old Socket 370 system so that I can test the CPUs before (semi-)permanently attaching them to the xbox motherboards.

Batch sales would work for me but this isn't something I'll likely pursue beyond the 10 that I've set my mind to. I typically pick up a project, go nuts with it, and move on. My plan is to build a total of 10 xboxes with upgrades 'done right'. I've also decided that I should focus on the CPU + RAM upgrade only, and leave further options open. Costs shouldn't be inflated by adding a €35+ openxenium if the end-user is perfectly happy with a zero-cost TSOP solution. Or someone already has a modchip lying around which they'd like to (re-)use, or maybe they prefer a dead simple Aladdin/Jafar. I feel that it is not up to me to force choices upon anyone, but I do not want to offer every possible combination either, so the logical approach is to offer the bare package at an affordable price where further tinkering remains entirely optional. By 'done right', I mean the quality of the performed upgrades should be excellent and without compromise. The resulting systems should be reliable and brought into good shape with (preventative) maintenance carried out. That, in my opinion, entails at least the following: leaky clock supercap removal + thorough cleaning of any leakage that has already occurred; all residue must be scraped away, resulting bare copper re-tinned or solder mask reapplied all electrolytic capacitors replaced, regardless of whether or not they've bulged, with new Rubycon/Nichicon/Panasonic, from a reputable vendor (so mouser/digikey/farnell, not some dried up stock from the bottom of some abandoned warehouse in China) after upgrades are applied: ultrasonic cleaning to remove all remnants of flux, dust and other crap that's been gathering inside for 20 year. Those might sounds obvious but at the same time I've read of an upgraded console that supposedly lived for some 20 hours before giving in to poor capacitors. That's upsetting but entirely avoidable. Another point I want to focus on is the quality of the BGA rework. For starters that means we will not be using heat guns or paint strippers... In fact I'd prefer not to use manual hot-air at all. Rather, I will employ my reasonably sophisticated BGA rework station with temperature controlled profiles, so as to obtain a repeatable process giving consistent results for each install. I'll be using leaded solder balls underneath the interposer, and a solder paste with a Bismuth composition, i.e. a paste that melts at temperature lower than regular leaded solder. For my first device I used the same soldering profile for both passes, but ideally, soldering down the Tualatin should use a profile where less heat is applied from the bottom (since this might reflow the interposer itself) and it should be tailored to the lower melting point of the solder paste too. The BGA station is equipped with split vision so aligning the interposer, despite lack of visual markers, is easily done by overlaying the top/bottom balls/pads. Finally, I've been thinking about heatsink solutions. Nothing definitive here just yet, but I've already realized that the Tualatins' internal heat spreader and lower operating voltage of just 1.45V contribute massively to good temperatures. Reusing the original heat sink with fins slightly trimmed, held onto the processor using a fairly simple polypropylene (heat resistant) 3-d printed jig combined with a reasonably effective thermal paste should yield excellent results. So that's the plan. I'll try to keep a bit of a logbook in this thread and add some progress pictures every now and then.

Alternatives: For U1 (NC7WZ07P6X) --> https://www.digikey.nl/nl/products/detail/texas-instruments/SN74AHC1G32TDBVRQ1/696627 For U2 (NC7SZ32M5X) --> https://www.digikey.nl/nl/products/detail/nexperia-usa-inc/74AUP2G3407GWH/4743668 For OSC1 (OSC SG3030B) --> https://www.digikey.nl/nl/products/detail/cts-frequency-controls/CB3LV-3I-32M768000/663659

I'm in The Netherlands

Last week I purchased a nice OG to revisit a console that I'd had so much fun with 2 decades ago and to do some modding on. I set out to finally recreate one of those Friendtech/trusty/n64freak consoles that I'd wanted to do for a long time, but unfortunately never followed up with. This was made infinitely simpler after n64freak opened up sales of his bare interposer boards, so now the daunting amount of work for engineering these boards myself from the Friendtech patent file and datasheets can be skipped. I sourced the components for the clock switching circuit on the interposer, which totaled an astonishing €5 from Digikey, while I needed to spend €50 to qualify for free shipping. This quickly spiraled out of control, I ordered everything x10... There's another 10 CPUs coming my way and there's a 10-high stack of never-been-opened xboxes behind me already. While awaiting components to arrive, I've been reading about this upgrade and this left me the impression that these CPU-upgraded consoles at some point were highly sought after. I'd like to gauge current interest and am trying to get global idea of what these units should yield when sold. I was thinking of offering the following for €275: - Clean motherboard with CPU upgraded to a 1.4GHz/512kB cache Tualatin using n64freak's interposer - RAM upgraded to 128MB by installing the 4 additional chips - OpenXenium modchip installed (or only with a flashed BIOS for some discount) - no PSU, HDD, DVD, case since cost of shipping twice easily exceeds sourcing an xbox locally for most locations I still have to think about a proper reliable solution for the heatsink if these boards are to be shipped. Any thoughts?