Restoration of an awesome 386 retro machine (Part1)

[Music] hello and welcome i think it's time for a nice retro pc restoration video again and here we go i got this old pal from ebay a long time ago but i didn't have time to take care of it until today it is very dirty but i like how it looks it is compact and though it has two base for five and quarter inch drives with famous mitsumi quad speed cd-rom already installed the buttons are very sticky as well as you see the turbo button stalls when pressed probably held by dirt inside anyway the case also has the seven sigman display which i love to see in retro machines this is the front so far let's see what we have on the back side as you see the slots are placed horizontally so the board must have some sort of razor card inside here we have a multi-i o controller down here is the graphics card and not much else to say instead of one bracket there is a hole probably some hardware was removed by a previous owner maybe sound card okay what do i know about this machine it was sold as non-functional it shouldn't even turn on as far as i know another bad thing is that this computer was unfortunately very badly packed and it got damaged during the shipment one corner broke off but the piece was likely still flying around in the box so i'll try to repair it later now let's take a look inside and see what we have there the first card is the multi o controller with integrated ide and floppy support a very nice graphics adapter tank et4000 with one megabyte memory on board this is one of the fastest iso graphics cards you could get back in the days it is superb surprise i'm very very glad about it okay let's take a look at the main board there you can see the green cyrix cpu already but there is something else i'm currently looking at i'm quite sure that this is not the original main board in this case as you can see it has vlb slots which can be used for considerably faster graphics card but these slots are absolutely useless in this case this one has only iso razor card with three 16 bits and two 8-bit slots so we can install on the iso expansion cards into this system so this main board whether it's a vlp slot is an absolute overkill well anyway let's take a closer look at it i already mentioned this cyrix cpu it is a dx40 megahertz one the board seems to have 256 kilobytes of level 2 cache furthermore the main board is supplied with mixed memory modules one four megabytes 72 pin and four one megabyte 30 pnc memory modules so there are eight megabytes ram all together luckily this board has a cell battery which usually doesn't leak so there is no damage from linking electrolyte that gives us a good chance that the board is still alive okay let's give it a try i already checked the board for shorts and it looks good if the main board works at all the pc speaker should give us some beeps that sounds like memory error if everything would be okay the board would make one long and eight short bibs for missing graphics card let's remove the four megabytes memory module and see if something changes nope unfortunately the same result let's remove the memory completely and yes at least the board noticed that there is now no memory installed at all ok maybe the memory modules are bad here i have one module which i definitely know is working and also compatible with this board no we are getting the same signals yeah i know this board actually quite good it is an fic-486 gvt-2 and it is really error-prone i repaired many of such ports in the past already here is one example it is the same board just with green pcb and it had the same issues before that the memory was not detected properly i guess i will spend some time another day trying to get this one working again but for today's build i would like not to take this board anyway and here is why as i told before i assume that this was not the original board of our retro pc and was actually some later upgrade since this board has a vlb slots but the razer card is iso only it would be quite a waste to use this main board in this system for this build only a pure iso main board would make sense and first i wanted to go with this cheapo 486 board however i wanted to make this retro pc really cool and didn't want to use anything low end like this if you follow my channel you will know that i already made multiple videos about retro pc's builds and restorations well i already covered setups from various generations like 286 486 and even with amd ethelon64 cpus however i never made a video building a retro pc from my favorite retrogeneration a 386. for this purpose i decided to go with this really nice main board hot307 made by shuttle currently it is a 33 megahertz 386 dx cpu by amd but i also have a 40 megahertz cpu in my spares box so i will max out the configuration this board is iso only it has support for level 2 cache and supports up to 32 megabytes of ram so there should be plenty of possibilities to get this one to a top 386 machine back to the case it is very dirty is yellowed and broken so i have to disassemble it completely for proper cleaning and repairing [Music] the three and a half inch hard drive is hiding in the five and quarter inch bay hauled by metal braces right under the cd-rom drive it's seagate st3491a with capacity of 428 megabytes if it's still working i'm curious if something interesting can be found there and here right under the three and a half inch drive cage there is another evidence that the main boat was not the original one here you can see the screw holder which is far beyond of the main board geometry which was installed here the main board ends about here so the screw is a left over from a mainboard which was previously installed in this machine now let's remove the power supply unit to test it on the bench the atp is used had external mains power switch which in this case is screwed to the front later for 80x the massive mains power switch was replaced by a small digital one making it less dangerous for users and allowing to control the power switch from software so let's see if the psu shows some signs of life nope seems to be dead well there is one thing many pcus don't turn on at all if there is no load detected for this purpose i am always using this broken hard drive let's connect it and see once again what happens nothing happens time to open the psu and take a look inside ok this looks really clean i guess someone was already here and i instantly can see that the fuse is missing i guess this sticker says that we need slow 250 volts 5 amps fuse i have one fuse which should fit let's put it into the holder but before i turn on the pcu again let's take the pcb out of the case and see if there is something suspicious to see maybe the fuse was previously damaged by a reason when working with a psu always discharge the main caps first using a powered resistor like this one the caps will not be charged in this case since without the fuse the pcu was off for a very long time so the caps must be discharged already but if they would be charged it wouldn't be deadly but it could hurt if you touch the leads well the bottom of the pcb looks clean i checked it for shorts and i didn't find anything wrong with it let's put it back and give it another try i will connect the hard drive again to give it some load oh when i turn it on now the fan rotates briefly but the pcu switches off with this high pitched sound like a short or something but since there is no short on the board which i could find obviously let's add some load to be sure that the pcu doesn't turn off because of too low power consumption here i have a main board which is completely dead however it has no shorts and it still should generate some load in addition to the hard drive which uh i already connected and here you go the dcu is working indeed let's measure some voltage 5 volts 12 volts is a little bit low but still in limits i guess minus 12 volts looks good and last but not least minus 5 volts perfect interesting the psu seems to be okay and this is the first time for me that the hard drive alone was not enough load to get it on so if you test a pcu which seems to be dead just add some load and give it another try this is by the way related to both 80 and 80x power supplies and in regards of the pcu one thing left to do clean the fan and add some drops of machine oil when putting back the fan into the pcu always pay attention to the direction of the airflow the arrows are usually drawn on the cage of the fan and you want the air to be blown out of the case otherwise your psu will turn into a vacuum cleaner that will suck all the dust into the pc once enough dust is inside it will not be cooled properly anymore and can overheat and even short and damage your main ports and other parts and back to the case rod i remove the old sticker using my guitar platform the best tool if you want to avoid scratches on your plastic by the way you can also use it to play guitar excellent i removed the badge as well since i have a much better alternative for it the floppy drive is also super dirty so the front will have to be cleaned as well i'll use the opportunity to look inside the floppy drive oh it looks to be really clean so i leave it as is and the same procedure for the cd-rom drive the front seems to be also very dirty you can remove the plastic parts by just lifting the latch with a screwdriver to remove the plastic front of the cd shelf itself it is not quite simple on this drive usually the cd drives have a hole where you can press with a thin wire to open the cage manually but not in this model unfortunately here it must be disassembled completely and the easiest way is to connect a power supply and press the eject button to remove the front part you have to gently rotate and push it down or up as in my case since i turned the drive upside down just as with the floppy drive already the cd drive seems also to be very clean inside even the foam is still in fine condition this is quite unusual for this age and normally the form is already rotten away all the plastic parts are now going into the soapy bath even the broken off corner after washing and drying let's repair the broken corner of the front part i am using plastic glue to put back the broken off part this glue is usually used to glue plastic models like airplanes ships and so on and this glue kind of melts the plastic surface and welds two parts together after 15 minutes of drying i'll add some support from the back side therefore i'm using some super glue and a spoon of baking soda this reacts in a blink of an eye and results in super hard compound which should give enough strength to the broken corner now the case front is very much yellowed you can clearly see the bright spot where the old dirty sticker was it looks in real even worse than through the camera believe me to find this let's use some peroxide for retrobriting today we have a nice sunny day just perfect for this procedure the other plastic parts will join the front panel as well retrobritic will take some hours let's take a look at the razer card so far as you can see it provides three 16-bit iso slots on one side and two additional 8-bit slots on the other the good news is that the 8-bit slots can be extended to 16-bit as well at least the pcb is prepared for it and already has holes and traces for the extension i already got here two iso extension slots from another dead main board however it is not very handy to solder the iso slots on the other side between of the already available slots i could damage the installed slots by touching them with a hard soldering iron furthermore i would like to install the missing capacitors which the manufacturer probably left out because of economical reasons they are absolutely optional but they provide better power supply stability which is even more important when the eraser card should carry all five full-blown 16-bit slots yeah and unfortunately the lower iso slot is also in the way so the caps cannot be soldered properly to simplify the procedure i will desolder all the 16 bit iso slots extensions then solder the caps and then solder the iso slots back in place one after another in an order where they are not in the way and here how it looks like now the razer card can carry up to 5 full size 16 bit iso cards if needed two from one side and three from another the caps will help to stabilize the power supply back to the main boards i would like to make some improvements before building it into the case first of all the port has currently only four megabytes of memory and i would like to upgrade it to eight megabytes second this port has currently a 33 megahertz cpu and i would like to go with 40. to get the cpu out of the socket you can use a special tool but i don't have such and flathead screwdriver does the job just as good insert it between the socket and the cpu and gently start to turn it until the cpu starts to come out don't stress it too much and repeat the same from multiple sides until the cpu comes completely out of the socket and when inserting a new cpu always pay attention to the polarity the socket has no protection against wrong insertion so it is very simple to damage the cpu or mainboard by shorting the contacts to get the cpu clock to 40 megahertz the crystal oscillator has to be changed as well if you saw my video about 386 as x overclocking you will remember that the clock is defined by this crystal oscillator it usually delivers the double frequency of the cpu we had 33 megahertz cpu on this board so the crystal oscillator was megahertz to get the cpu to 40 megahertz the crystal oscillator has to be replaced by 80 megahertz version just as i said these board has already four ram modules installed one megabyte each i will add another four megabytes to get to eight megabytes altogether theoretically this main board can handle up to 32 megabytes with eight four megabytes models but i think it would be a little bit too much since 8 megabytes is already more than enough for almost everything what this system should be able to handle another thing i would like to add to this board is a cr2032 battery this cannot be simply installed in place of the rechargeable battery which was previously installed here this circuit here is responsible for recharging the battery and must be modified as you can see the charging current is around 63 milliamps and this would probably damage the battery in the long term i already made a video once before where i explained what has to be done if you want to use a cr2032 instead of the rechargeable barrel battery on such main board in this case i bent one lag of the second diode to the output of the first one this way the 5 volt voltage will go directly to the board and not to the battery first so the battery will not be charged anymore this change is completely reversible and can be turned back to the original state if needed okay time to put things back together [Music] i just realized that i forgot to retrobrite the buttons here you can see the color difference between the buttons and the front panel at least it is now very good visible how yellowed the front panel was the buttons will now take a place in the sun as well to match the color of the front panel so far to test the front panel display i will connect external power supply oh nice the display seems to be functional and here we have another evidence that the main port was not the original one as you can see it shows 25 megahertz but the cpu which was installed in this machine was a 40 megahertz one this computer was definitely upgraded back in the days but the seven segments display was not set properly after the upgrade and was left at 25 megahertz probably the original cpu in this machine was a 486 or a 386 with megahertz and if i switch between turbo and non-turbo mode the display jumps between 8 and 25 megahertz well as you see this display doesn't really show the actual cpu frequency it is just a fancy led like rgb light in modern gaming pcs nice but totally useless anyway it gives a cool retro look to this pc and i absolutely love it you can set up the numbers to show by resetting these jumpers one row is for the first digit and the second row is for the second one as you can see if i pull or set the jumper i can turn parts of the seven segment display on or off so and after some poking around i got the 40 megahertz on the display now i can switch using turbo button between 40 and 8 megahertz as you can see all the cables from the front panel like power led turbo led turbo button and etc have to be connected to the main board and the at power connector never forget the polarity the background cables must be in the middle now to the hard drive before putting it into the case i have to make a note of its geometry this st3491a contains 899 cylinders 15 heads and 62 sectors which makes 428.1 megabytes in capacity i will need this information later to set up the bios properly furthermore i would like to use this cd-rom drive again in this machine as well and i want to use both cdrom and hard drive on the same ide cable so i have to check the master slave jumpers the cd-rom drive is already set to slave this is right and hard drive has a sticker on top to describe the settings most left is the master setting which we need the jumper itself is on the bottom and is set to master mode indeed the hard drive was used in five and quarter inch bay before with some holders but i would prefer to leave that one open for future and install the three and a half inch hard drive together with the floppy drive into three and a half inch drive cage meanwhile the front panel buttons got bright again and can be installed where they belong there is not a lot of space in this case so cable management is a little bit of challenge here i folded the ribbon cables like that to get 90 degrees angles and i printed such a clip on my 3d printer to hold the cables folded together like that the case is almost done but there is one thing left the steel cover is extremely scratched and after so much effort i don't want to use it like that so i washed it properly and sanded the old paint as good as i could by the way i always add some water when i sending paint from the metal this makes the procedure less dusty and the result smoother but you have to wash and dry the surface properly afterwards when everything is dry and clean it is time to paint the cover i suggest three colors for the retro pcs rel 9001 through rel 9003 it depends on the color of the plastic of the case which one is the best to use if your plastic is slightly yellowed i suggest to go with rail9001 if it's more grayish i'd go with rel 9002 or 9003 for this case rail 9003 would be probably the better choice but i had rel 9001 at hand so i used what i had for the best result i painted multiple times in thin layers and let it dry for about 12 hours between every layer as long as the paint dries i guess it is time to power up the machine and see if it works at all yay and it does you can clearly hear the memory card ticks and the post beep also the turbo button works the way it should okay let's see what we have on the hard drive as you see when trying to boot the machine doesn't see the hard drive at all so it has to be set up in the bios this is where the previously noted hard drive geometry comes handy in the bios the hard drive type has to be set to 4d7 and the geometry can be set manually to the values which were written on the hard drive and here we go it says starting from ms-dos obviously a german ms-dos version it is trying to load some creative drivers probably there was a creative sound blaster previously installed in this machine ah and hit boots into windows 311 and complains about a missing song blaster 16. by the way sorry about cut off edges my vga to hdmi adapter seems not to work properly i will have to take a closer look at it another day luckily the most of the screen is still visible i also have currently no mouse connected so the windows fun will not last too long i guess anyway what do we see here some texas software maps and guides fine artists by microsoft kids and some not very exciting office games let's see what we have in dos okay i already can see some drivers there is norton directory let's see if it has norton commander oh yes it has okay a lot of drivers genius mouse 84 000 sound blaster some learning and financial software tools norton commander some postal codes tools q copy is a tool to copy floppies as far as i know some kind of anti-virus software and the windows 311 itself well actually nothing exciting probably this pc was used in some office i guess okay this video already got quite long and i think i will continue in the next part the case of this pc is almost done the cover is still drying but everything looks as good as new the next part i'm going to make a clean software installation some games and benchmarks i already replaced the cpu and added some ram but i would like to make an absolutely amazing 386 pc and i plan to make some very exciting upgrades and benchmark the system to see how good it will get so if you are curious to see how this setup ends up what kind of upgrades it will get and how the final case will look like you are welcome to join me in the second part and so far if you like this video you know what to do and i say thank you and goodbye

Channel: Necroware

Views: 18,458

Keywords: retro, hardware, soldering, repair, review, nerd

Id: j1hGepWb6nY

Length: 28min 29sec (1709 seconds)

Published: Sat Jul 03 2021