VOGONS


Reply 29060 of 29216, by Susanin79

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Tried to figure out why Pentium OverDrive CPU didn't work at Jetway J-437 motherboard.
With the installed CPU 5V rail is shorted to the ground, to check this I decided to find any pins in socket that connected to the ground and what pins are connected to the power rail.
Some of the Vcc pins definitely sorted to the ground so I decided to remove any jumpers and continue to measure the shorts without them. You can see the tracing result on the picture. The blue circle mean that pin connected to the Ground and the red one means that pin is connected to the Voltage regulator.
Then I tried to trace the jumpers PINs and found that documentation didn't fit the jumpers on the motherboard. With all this new information I thought that I found the cause of the issue, but not, the shorts still exist with the any of the jumpers configuration. Seems that it would be better to create a separate thread.

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Reply 29061 of 29216, by MusicStudent1

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I rebuilt three donated desktops recently. A Sony Vaio desktop from 1997, a Compaq from 2001, and a Compaq from 2007. Two had non functioning power supplies and another had Both a bad power supply and bad Maxtor hard drive.

I got all 3 up and running. My goal is to play Armored Fist from 1994 on a fast processor in true DOS with functioning sound. So far, the fastest I’ve gotten is an AMD K2 450MHZ CPU with an ES 1371 PCI sound card.

I have an ESS Solo-1 ES1938S PCI Sound Card coming from eBay that I’m going to try in a 3GHZ Intel PC running DOS 6.22.

Will it work? If sound works under DOS in a 3GHZ CPU system, I’m going to be pretty proud. I’m not optimistic, though. There’s always some problem with DOS, fast CPUs and PCI cards.

Reply 29062 of 29216, by Horun

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Dug thru my boxes of old saved CD's looking for old Cyberlink PowerDVD versions, found a few but..
Found lots mid 90's stuff had forgot about or thought was lost. Asus driver CD M023 for my SP98AGP-X board, my CT-3990 cd, some Plextor CD's that came with various drives bought, 1996 Diamond GT driver cd....
just to name a few from hardware purchased long ago plus much more (sigh). May not sound sound like much work but have old stuff scattered in so many places since the last move am forgetting where what is where is what where ...
and it takes lots of time digging thru boxes scattered around... 🙁

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 29063 of 29216, by PC@LIVE

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Horun wrote on 2025-01-11, 05:51:
Dug thru my boxes of old saved CD's looking for old Cyberlink PowerDVD versions, found a few but.. Found lots mid 90's stuff had […]
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Dug thru my boxes of old saved CD's looking for old Cyberlink PowerDVD versions, found a few but..
Found lots mid 90's stuff had forgot about or thought was lost. Asus driver CD M023 for my SP98AGP-X board, my CT-3990 cd, some Plextor CD's that came with various drives bought, 1996 Diamond GT driver cd....
just to name a few from hardware purchased long ago plus much more (sigh). May not sound sound like much work but have old stuff scattered in so many places since the last move am forgetting where what is where is what where ...
and it takes lots of time digging thru boxes scattered around... 🙁

I can imagine 💭, for me it's getting complicated whatever you're looking for, both software and hardware, maybe 🤔 the solution could be a database, cataloging everything, for CDs I remember there was a program that did something similar, but don't tell you what it was, the alternative is to waste a lot of time, except that you have a list that you can scan, you usually find it if the CDs come from PC magazines.

AMD 286-16 287-10 4MB HD 45MB VGA 256KB
AMD 386DX-40 Intel 387 8MB HD 81MB VGA 256KB
Cyrix 486DLC-40 IIT387-40 8MB VGA 512KB
AMD 5X86-133 16MB VGA VLB CL5428 2MB and many others
AMD K62+ 550 SOYO 5EMA+ and many others
AST Pentium Pro 200 MHz L2 256KB

Reply 29065 of 29216, by dr_st

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Is patching vanilla Heretic using HHE so that Iron Liches actually fly a "retro activity"? Or is this thread about hardware only? 😜
https://www.youtube.com/watch?v=95ufVDGQ4P8

https://cloakedthargoid.wordpress.com/ - Random content on hardware, software, games and toys

Reply 29066 of 29216, by H3nrik V!

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Playing with unattended install of Windows 98SE. Why didn't I learn that like 27 years ago 🤣 that's so convenient for a computer with frequent hardware and driver changes, resulting in fogups 😎

If it's dual it's kind of cool ... 😎

--- GA586DX --- P2B-DS --- BP6 ---

Please use the "quote" option if asking questions to what I write - it will really up the chances of me noticing 😀

Reply 29067 of 29216, by 3dnow

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Browsing this forum at 33Kb/s using my DIY dial-up internet server. In fact every time this year so far I've used a dial-up connection to browse and post on Vogons (IDK but it feels right to do it like this). Can't wait to get a PABX so that all my retro PCs can dial into each other.

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Reply 29068 of 29216, by luckybob

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3dnow wrote on 2025-01-13, 03:01:

Browsing this forum at 33Kb/s using my DIY dial-up internet server. In fact every time this year so far I've used a dial-up connection to browse and post on Vogons (IDK but it feels right to do it like this).

Dictionary
Definitions from Oxford Languages · Learn more
mas·och·ism
/ˈmazəˌkizəm/
noun
the tendency to derive pleasure, especially sexual gratification, from one's own pain or humiliation.
"with things such as bondage and masochism, it's all right if you both go for it"
(in general use) the enjoyment of what appears to be painful or tiresome.
"isn't there some masochism involved in taking on this kind of project?"

It is a mistake to think you can solve any major problems just with potatoes.

Reply 29069 of 29216, by RetroPCCupboard

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I have an issue with my Pentium III 933Mhz / Geforce 2 GTS build in that I want it in a SFF PC case but my BeQuiet 450W SFX PSU fails to power the board. But a full ATX PSU does fine. So, I have bitten the bullet and bought a much more expensive PSU that supports 20A on the 5V rail.

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Seems wrong to spend more on the PSU than I did on the other parts.... but, have to say, this PSU feels so high quality compared to the 450W BeQuiet one.

Next issue though is that I wasn't paying attention to the specs and didn't notice that the ATX power is 24 pin rather than 20+4 pin, and also it doesn't have a berg connector for floppy drive/gotek. So, I have had to order adapters.

Reply 29070 of 29216, by Veeb0rg

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3dnow wrote on 2025-01-13, 03:01:
Browsing this forum at 33Kb/s using my DIY dial-up internet server. In fact every time this year so far I've used a dial-up conn […]
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Browsing this forum at 33Kb/s using my DIY dial-up internet server. In fact every time this year so far I've used a dial-up connection to browse and post on Vogons (IDK but it feels right to do it like this). Can't wait to get a PABX so that all my retro PCs can dial into each other.

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I've got a Cisco 2821 that I've setup for a similar reason. I even have a VOIP connection so I can dial out or others can Dial in. I'm working on setting up an IAD2432 so I can connect a bank of digital modems for a 56k connection. The digital modems are proving to be difficult/expensive though.

https://www.youtube.com/watch?v=uHZ7A8DFPNo

Reply 29071 of 29216, by 3dnow

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Veeb0rg wrote on 2025-01-14, 05:14:

I've got a Cisco 2821 that I've setup for a similar reason. I even have a VOIP connection so I can dial out or others can Dial in. I'm working on setting up an IAD2432 so I can connect a bank of digital modems for a 56k connection. The digital modems are proving to be difficult/expensive though.

https://www.youtube.com/watch?v=uHZ7A8DFPNo

I've all but given up on a 56k setup due to cost.

The simple solution is to get a USR Courier I-Modem (or any other brand that's capable of dialing out), an ISDN line simulator, a terminal adapter modem, and finally your 56k modem. This can go up to V.90 and you don't need any special software on the server compared to using an analog modem. The downside is that ISDN line simulators cost hundreds of USD.

I also looked into a Patton 2960 RAS with built in V.92 modems; but it's not only expensive, the modems are PRI-ISDN (T1). A PRI to BRI line splitter would also be needed and they are just as costly.

Kudos to you for getting the IAD2432. I pray that you manage to find some digital modems that won't break the bank.

Reply 29072 of 29216, by vutt

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Stress testing my recent acquisition in my "standard issue reasonably priced testbedcarte".

Actually had my facepalm moment. One who have been building Socket 7/S370 systems since 90-ies should pay attention that CPU sink mounting clip pressure point is not symmetrical...
I could not understand why my 933MHZ CPU is running at 66C on BIOS screen...

There is however one concern - CPU SL52Q VCORE suppose to be 1.75V but Bios/win tools are showing 1.8V. I need to find my multimeter...

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Reply 29073 of 29216, by Veeb0rg

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3dnow wrote on 2025-01-14, 13:03:
I've all but given up on a 56k setup due to cost. […]
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Veeb0rg wrote on 2025-01-14, 05:14:

I've got a Cisco 2821 that I've setup for a similar reason. I even have a VOIP connection so I can dial out or others can Dial in. I'm working on setting up an IAD2432 so I can connect a bank of digital modems for a 56k connection. The digital modems are proving to be difficult/expensive though.

https://www.youtube.com/watch?v=uHZ7A8DFPNo

I've all but given up on a 56k setup due to cost.

The simple solution is to get a USR Courier I-Modem (or any other brand that's capable of dialing out), an ISDN line simulator, a terminal adapter modem, and finally your 56k modem. This can go up to V.90 and you don't need any special software on the server compared to using an analog modem. The downside is that ISDN line simulators cost hundreds of USD.

I also looked into a Patton 2960 RAS with built in V.92 modems; but it's not only expensive, the modems are PRI-ISDN (T1). A PRI to BRI line splitter would also be needed and they are just as costly.

Kudos to you for getting the IAD2432. I pray that you manage to find some digital modems that won't break the bank.

I've been searching for an I-courier for a while and one of those Patton units they're either none listed or way out of budget. its just a matter of patience. Something will turn up.

Good luck with your setup!

Reply 29074 of 29216, by BetaC

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Now that I have consolidated my potential machines a bit, and chose to go with the case I previously purchased, I went a little overboard with a joke.

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It's a turn of the millennium case, so I wanted to put stickers on it, and a dumb part of me said "Why not throw every different combo I can have in this machine on the front". And now I have exactly that, and a NASCAR looking front panel.

rfbu29-99.png
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uz9qgb-6.png

Reply 29075 of 29216, by Nexxen

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vutt wrote on 2025-01-14, 15:39:
Stress testing my recent acquisition in my "standard issue reasonably priced testbedcarte". […]
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Stress testing my recent acquisition in my "standard issue reasonably priced testbedcarte".

Actually had my facepalm moment. One who have been building Socket 7/S370 systems since 90-ies should pay attention that CPU sink mounting clip pressure point is not symmetrical...
I could not understand why my 933MHZ CPU is running at 66C on BIOS screen...

There is however one concern - CPU SL52Q VCORE suppose to be 1.75V but Bios/win tools are showing 1.8V. I need to find my multimeter...

Stackable. You gave me a nice idea.
Thanks for posting it.

PC#1 Pentium 233 MMX - 98SE
PC#2 PIII-1Ghz - 98SE/W2K

Reply 29076 of 29216, by Thermalwrong

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Thermalwrong wrote on 2021-08-15, 23:47:
I didn't just have one laptop that had a bad keyboard. I bought a Toshiba Tecra 730CDT recently to get hold of a Toshiba DeskSta […]
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I didn't just have one laptop that had a bad keyboard. I bought a Toshiba Tecra 730CDT recently to get hold of a Toshiba DeskStation V - both were horribly rusted and corroded, but both mostly work.

The dock likes powering off after a few minutes of use, I'm still wondering where to start diagnostics, could it be heat since the fan by the PSU doesn't appear to be doing anything, or maybe capacitors somewhere, either on the board or hte integrated power supply?
I've so far dismantled it, put it back together and removed the pins in the dock's lock so it can be put between regular and emergency eject mode without a key.

The Tecra 730CDT was so badly corroded that I had to fully dismantle it and carefully remove the electrolyte corrosion from the magnesium frame. It's been working but the keyboard's Up key and maybe some others weren't working. A replacement keyboard would cost £30 and I'm not interested in paying that, especially having fixed one keyboard, so I've worked to fix this one too.

These '90s laptops have nice big keyboard frames that use plastic stakes (sometimes screws) to hold in the membrane to the keyboard's backplate.
I pulled the keyboard apart, this time using the soldering iron at 200C on each of these pegs so that they could deform without breaking, for later use.
Took apart the keyboard and started following the traces on both sides but doing it just by eye is more work than it's worth. I taped it to the desk to get it flat then took a picture of both sides and drew a layer over the top with lines to visualise it. Nothing wrong with the bottom side:

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The topside is much more complex to follow - notice those little black traces connecting each pad, each one is about a 10k resistor. Following it, the discolouration was visible from my picture, one of the top traces at the upper edge of the keyboard has discoloured and the connection has gone from 20 ohms to 60k ohms:

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I tried using the conductive paint again, but it didn't do much good. I found a better way this time - the self adhesive copper tape is sticky on one side and conductive on the other. Stick the conductive tape over the part that needs replacing and a few mm longer, fold over the ends so the conductive side is touching the membrane trace at each end. That bridges the connection and provides a trace that's held in place, but maybe a fresh conductive ink pen would be better.

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Then put Kapton / polyamide tape over the top which keeps it connected. Then I put some extra Kapton tape over the copper just in case it could short on anything.

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Tested it one last time and the up key now works, no random key presses so it's all melted back together, again using the soldering iron to press on them but with a bigger round tip to squish it nicely:

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Yay! now the Tecra 730CDT is back to 100% working. I've got quite a full set now - Tecra 730CDT, Tecra 740CDT and Tecra 750CDT 😁

*sigh* The other day I found that the repair I did on my Toshiba Tecra 730CDT was not working. The keys that are broken are quite important so I had to take the keyboard apart again, using the soldering iron to undo all the heat stakes so I could check out what was wrong.
In hindsight, the repair I did here may not have been the fault, I think, because there was a break further up the line where corrosion damage eventually killed some more of the trace. Quite possible the conductive adhesive for the copper wasn't making good enough contact any more. Conductive paint is much better but harder to apply.
I pulled off my copper tape repair which resulted in ripping the membrane on the edge. 🙁 So I had to clean off and re-route three keyboard traces through the smaller area.

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At least now I've learned some very efficient methods for doing keyboard membrane trace repair. Now I use the cheap silver conductive paint that you get from china in a syringe, but to apply it I take off the needle part and use a rubber thermal paste spreader nozzle thing as a brush to get a nice even coat. To lay down the new traces I use some cheap polyimide tape (which has poor adhesion) as masking tape to get the lines, then paint on the new trace.
This conductive paint has to be heat cured though, so I use my USB-PD hotplate with a thermal pad on top to bring it up to 100c and that then starts conducting and I can then check for crossover with other traces, scraping off paint where that occurs.
This method works really well, having the thermal pad and hotplate keep the membrane in place makes it easier to work on.

Reply 29077 of 29216, by Veeb0rg

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3dnow wrote on 2025-01-14, 13:03:
I've all but given up on a 56k setup due to cost. […]
Show full quote
Veeb0rg wrote on 2025-01-14, 05:14:

I've got a Cisco 2821 that I've setup for a similar reason. I even have a VOIP connection so I can dial out or others can Dial in. I'm working on setting up an IAD2432 so I can connect a bank of digital modems for a 56k connection. The digital modems are proving to be difficult/expensive though.

https://www.youtube.com/watch?v=uHZ7A8DFPNo

I've all but given up on a 56k setup due to cost.

The simple solution is to get a USR Courier I-Modem (or any other brand that's capable of dialing out), an ISDN line simulator, a terminal adapter modem, and finally your 56k modem. This can go up to V.90 and you don't need any special software on the server compared to using an analog modem. The downside is that ISDN line simulators cost hundreds of USD.

I also looked into a Patton 2960 RAS with built in V.92 modems; but it's not only expensive, the modems are PRI-ISDN (T1). A PRI to BRI line splitter would also be needed and they are just as costly.

Kudos to you for getting the IAD2432. I pray that you manage to find some digital modems that won't break the bank.

Funny thing, made that post about not finding a budget friendly digital modem pool and later on had an offer accepted on an Equinox Digital modem pool. Should have 5x 6 digital modem cards in it and a T1 connection.

Reply 29078 of 29216, by Daniël Oosterhuis

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Spent the last weekend and yesterday afternoon building a new logic board for my SEGA MegaCD.
The previous one had severe cap leakage, leading to corroded solder joints that had completely let go on one side of the QFP.

My attempts to reflow it just started to cause bent pins and screwed up pads, as fighting against that amount of corrosion is futile.
So I decided to hold off on trying to continue to fix the original board, and wait for a new JLCPCB order of various PCBs and 3D printed things to tack on some new logic boards, as there do exist modern open source recreations of the main (Mega)CD logic boards.

However, someone on a Dutch classifieds site was selling some of their extras for 10 bucks a pop, so I decided to just buy that.
It was a HASL board, where I would probably have sprung for ENIG, but to be honest, the MegaDrives themselves are HASL (other than a few with carbon coated pins on the extension connector), and it doesn't seem like the MegaCD expansion connectors are all having metal reaction issues with those boards, so eh, it'll be fine.

Once the board was under the microscope, the first thing I tackled was the ASIC.
This will be the trickiest component to get soldered down correctly, so I want this done before continuing with the rest.

(Click on the thumbnails for full resolution pics)

ASIC1thumb.jpgASIC3thumb.jpg

ASIC2thumb.jpg

That went well, even the slightly malformed pins at least have a solid solder connection, and are not bridged together.
I have some footage from the microscope of soldering one of the sides of the QFP here, if it is of any interest.

Anyways, with the QFP down, I started fitting the rest of the components.
I was out of some capacitors and ROM socket that I thought I still had in stock, so I couldn't complete the work last weekend, but I got most of it on:

Boardthumb.jpgboardthumb.jpg

Yesterday I put the last bits on, which means it just needs an ultrasonic bath but is otherwise done!
I also added a slight mod for the save game chip, by installing a larger FRAM chip in place of the original SRAM, which does not need the battery to keep its data (Cypress rates it for 151 years of data retention after power off).

There's a mod where you run two extra address line pins to the 68k CPU, described on this page, which in tandem with a custom region-free BIOS allows full addressing of the chip's 32KB of memory without the use of bank switching.
That is a four times increase over the original 8KB, which usually gets filled up rather quickly.

finalthumb.jpg

So, the symptoms I was having on the previous board were that there was a persistent ticking sound, that coincided with stuttering on the BIOS splash screen music, alongside corrupted graphics at the BIOS splash screen (the MegaCD logo that shows off the rotational sprite manipulation was mostly invisible, sometimes showing corrupted bits of it), no life out of the CD drive, and a system hang the moment you'd go into the CD player interface.
There's some footage of that here, though I did not record the CD player interface hanging the system.

Well, what did I get on the first boot up of this board?
The good news, it's way better than before, as now the graphics corruption is complete gone, and the CD player interface now no longer hangs the system, as seen here.

The CD drive is still not showing signs of life, and the sound issue is still present.
But, for a first boot of a freshly populated-by-hand PCB with all sorts of fun SMD chips, I'm calling it a win either way!

I also haven't recapped the power board and CD drive yet, so I figured that would need to be addressed before moving on with any further diagnostics.
I was reading on the RetroSix Wiki that three 100uF capacitors on the power board in particular could cause "stuttering audio", though no sample was given of what that sounds like.

So just for a test, I recapped those three capacitors (not sure if I have the others on hand, if I had been more clever I'd have ordered those too...), which now results in a CD drive that's opening and closing the tray, and normal sound, but the video output has gone out (I checked and it's not the MegaDrive at fault).
I'm guessing with the CD drive now actually drawing power and operating to a certain degree, the rest of the crappy capacitors on the power board are strained harder, which might be causing the new problem, so I'm not too worried about is, especially as the recreated board wasn't messed with after the first power on test, soldering or components wise.

But I'm very happy with the current progress none the less 😀

sUd4xjs.gif

Reply 29079 of 29216, by PTherapist

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Daniël Oosterhuis wrote on 2025-01-15, 08:43:
Spent the last weekend and yesterday afternoon building a new logic board for my SEGA MegaCD. The previous one had severe cap le […]
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Spent the last weekend and yesterday afternoon building a new logic board for my SEGA MegaCD.
The previous one had severe cap leakage, leading to corroded solder joints that had completely let go on one side of the QFP.

My attempts to reflow it just started to cause bent pins and screwed up pads, as fighting against that amount of corrosion is futile.
So I decided to hold off on trying to continue to fix the original board, and wait for a new JLCPCB order of various PCBs and 3D printed things to tack on some new logic boards, as there do exist modern open source recreations of the main (Mega)CD logic boards.

However, someone on a Dutch classifieds site was selling some of their extras for 10 bucks a pop, so I decided to just buy that.
It was a HASL board, where I would probably have sprung for ENIG, but to be honest, the MegaDrives themselves are HASL (other than a few with carbon coated pins on the extension connector), and it doesn't seem like the MegaCD expansion connectors are all having metal reaction issues with those boards, so eh, it'll be fine.

Once the board was under the microscope, the first thing I tackled was the ASIC.
This will be the trickiest component to get soldered down correctly, so I want this done before continuing with the rest.

(Click on the thumbnails for full resolution pics)

ASIC1thumb.jpgASIC3thumb.jpg

ASIC2thumb.jpg

That went well, even the slightly malformed pins at least have a solid solder connection, and are not bridged together.
I have some footage from the microscope of soldering one of the sides of the QFP here, if it is of any interest.

Anyways, with the QFP down, I started fitting the rest of the components.
I was out of some capacitors and ROM socket that I thought I still had in stock, so I couldn't complete the work last weekend, but I got most of it on:

Boardthumb.jpgboardthumb.jpg

Yesterday I put the last bits on, which means it just needs an ultrasonic bath but is otherwise done!
I also added a slight mod for the save game chip, by installing a larger FRAM chip in place of the original SRAM, which does not need the battery to keep its data (Cypress rates it for 151 years of data retention after power off).

There's a mod where you run two extra address line pins to the 68k CPU, described on this page, which in tandem with a custom region-free BIOS allows full addressing of the chip's 32KB of memory without the use of bank switching.
That is a four times increase over the original 8KB, which usually gets filled up rather quickly.

finalthumb.jpg

So, the symptoms I was having on the previous board were that there was a persistent ticking sound, that coincided with stuttering on the BIOS splash screen music, alongside corrupted graphics at the BIOS splash screen (the MegaCD logo that shows off the rotational sprite manipulation was mostly invisible, sometimes showing corrupted bits of it), no life out of the CD drive, and a system hang the moment you'd go into the CD player interface.
There's some footage of that here, though I did not record the CD player interface hanging the system.

Well, what did I get on the first boot up of this board?
The good news, it's way better than before, as now the graphics corruption is complete gone, and the CD player interface now no longer hangs the system, as seen here.

The CD drive is still not showing signs of life, and the sound issue is still present.
But, for a first boot of a freshly populated-by-hand PCB with all sorts of fun SMD chips, I'm calling it a win either way!

I also haven't recapped the power board and CD drive yet, so I figured that would need to be addressed before moving on with any further diagnostics.
I was reading on the RetroSix Wiki that three 100uF capacitors on the power board in particular could cause "stuttering audio", though no sample was given of what that sounds like.

So just for a test, I recapped those three capacitors (not sure if I have the others on hand, if I had been more clever I'd have ordered those too...), which now results in a CD drive that's opening and closing the tray, and normal sound, but the video output has gone out (I checked and it's not the MegaDrive at fault).
I'm guessing with the CD drive now actually drawing power and operating to a certain degree, the rest of the crappy capacitors on the power board are strained harder, which might be causing the new problem, so I'm not too worried about is, especially as the recreated board wasn't messed with after the first power on test, soldering or components wise.

But I'm very happy with the current progress none the less 😀

I admire your dedication, the Model 1 Mega CD does need lots of work.

My soldering abilities are not up to the task, so I had my Mega CD main board sent off to be recapped last month. Luckily mine wasn't in too bad shape, only suffering from a dead SRAM chip that was replaced also with the FRAM mod.

I've heard people talk about recapping the CD & power boards too, but in my case everything seems to work fine now, so I'm leaving it be until it breaks haha.