I harvested some Samsung RAM chips from various Xboxes. 6 of them are from v1.6. I was lucky they did not have Hynix chips since they can't be used for RAM upgrades. I use the Xboxes for Xbox Media Center and arcade CoinOps. At least the CoinOps benefits from the 128MB upgrade. The RAM chips were easily removed with hot air. I also saved the 1.2-1.6 compatible PSUs. I replaced a lot of PSUs over ten years ago when I fixed and modified Xboxes. These should be enough for all the Xboxes I have left
It's easy if you have a flow and temperature controlled hot air rework station. Regular hot air guns are too hot in the hottest setting.
Pre-heater helps but not necessary with these chips. There are no difficult ground pads etc. All pins got loose about the same time.
Stuck with my XBOX 1.4 with IND BIOS. -SAMSUNG KD263238D-QC50 (334) - already were on xbox -SAMSUNG KD263238F-QC50 (546) - I have added. When I try to turn it on it fade 3 times like it have short circute with yellow/red led sparking in the end. May these chips not compatible or there is a shrt-circute indeed? Maybe I overheat it or something? Cant find maximum temperature ratings for these chips. Well, maybe someone had the same bad experience like mine and can make some advice. Thanks. ### I edited the post. Yellow/red blinking led. Maked all chips F. Still Yellow/Red. Maybe flux.
The yellow (orange) is usually what you get when there is no video cable connected. The xbox PIC checks some pins on it's video connector to detect what video it should output. If it can't find something connected to the connector, it changes green into orange. Flashing red and green (which you will probably have when you connect a video cable) is what you get when the cpu can't run properly. The xbox pic microcontroller expects some sign of life from the x86 processor. If tat doesn't happen within 200mS it will reset the x86. After 3 times it gives up and flashes red and green. You probably have a short on one of the ram chips (or a bad chip) that prevents the x86 from accessing it's other ram memory. Due to that, it's not working anymore. You almost need a microscope to check the ram chip pins for shorts. You can try with excessive flux and desolder wire to remove possible shorts, but there are 400 pin's that can be shorted. So, it's looking for a needle in a haystack without proper magnifying equipment.
Very interesting information (I mean box boot process). —Video cable is pluged in of course, cause I know about green/yellow ring when there is no cable. —I do have yellow/red that says it has no short but has problem with Ram. Have to check every single pin to be solder properly.
Every time I've attempted this mod with salvaged chips I get the same problem. I check and recheck that everything is soldered down well and even go as far as to remove them and test the xbox again only to find that it does still work. I think the problem is with trying to salvage the chips, its best to just buy new ones.
Do you know a reliable source for new chips? It's possible to find them at Aliexpresss/eBay but I don't know if they are really quality chips.
Finaly, got this working. Have to desolder all x8 RAM and clean up all (RAM's and board) to get rid of old Keller TT flux. It was a bad choise to use. After that I used rosin alcohol as flux. Cleaned up all board in a big container with isopropyl alcohol with 10% amount of acetone. And now it starts up normaly and it shows 128mb and IND BIOS into system info. Seems I am finaly did it. P.S. No, the RAM chips were bougth from Aliexpress, they are not salvage chips, they are brand new in fabric tape package without any signs of unpacking and of cource without any traces of solder iron. I bought 10 of them and I think I will buy them again someday. Here is the seller and his goods: https://ru.aliexpress.com/item/Free...1906140912.html?spm=2114.13010608.0.99.25LKhk P.P.S. And one more thing I don't get. When I desoldered all chips and cleaned up all board I tried to check all pads to be connected to ground - and surprise! On the bottom side all pads seems to be normal as it should (used datasheet to check) but when I checked the top's side RAM pads - all VddQ pins (like 2, 8...) are connected with VssQ/GND. Seems like bottom x4 RAM chips are in primary/master mode and x4 top RAM chips are in slave mode. I don.t know if it is like IDE - simply used that analogy. Really can't find any reasons how the top's side RAM works when chip's supply is grounded.
Samsung memory chips is a v1.6 - good. At least, it's not a 1.6b with Hynix lower speed memory chips. However, you can't upgrade a v1.6 Xbox's memory. There are no solder pad locations to add the 4 additional chips as on a v1.0-1.5 Xbox motherboard - 2 on top and 2 on bottom. V1.0-1.5 Memory Expansion - 4 DDR SDRAM Chips Samsung 128Mbit DDR SDRAM 1M x 32Bit x 4 Banks with Bi-directional Data Strobe and DLL - Double Data Rate Synchronous Dynamic RAMs - K4D263238[D, F, or M silicon revisions]-QC50. Hi-res Xbox Motherboard Images Xbox v1.0/1.1 and v1.6 motherboards see: https://imgur.com/a/PbHyZ I need to find a picture or take one of v1.2-1.5 motherboards. Other hi-res motherboard images both component and solder sides v1.1 and v1.6: http://diy.sickmods.net/Tutorials/Xbox1/Hi-Res_Scans/
i was thinking about the ram silver pins(image check red) that are soldered on the pcb motherboard if i had an extra xbox ram and copper wire really thin enough to solder those pins(image check red) with the extra ram on top of each other.
> So you intend to solder 400 tiny wires? > yes, if I had an extra ram Now that I'd like to see. Someone get this man "a ram"!
(You also need pads for the extra address lines, which I don't even know wether the 1.6 has. But sssh, don't burst his bubble )
