The dead battery is embedded in the Dallas RTC chip, it's also what is likely preventing the system from booting. You'll need to modify it or source a replacement.

hi thanks for your message i tried pulling out all of the 3 cards and just left the monitor card in i turned it on and it booted and the floppy disk drives powered on and the there were two beeps.
i then tried every card in the machine one at a time when i put in 2 of the cards it turned on but when i put the 3rd card in it didn't turn on so the 3rd card seems to be causing the machine not to boot
Ive taken the 3rd card back out and have taken a photo of it as im not sure what its for and what its spose to do

jude1977 wrote on 2026-06-08, 13:37:

Ive taken the 3rd card back out and have taken a photo of it as im not sure what its for and what its spose to do

That's an MFM hard drive controller card: https://theretroweb.com/expansioncards/s/west … tal-wd1002a-wx1

Interesting I didn’t know it was a mfm hard drive controller when it’s inserted in my machine it causes the machine not to boot at all is there a reason for this is there Spose to be a ribbon cable attached to

Also I have it in the back of the machine but I noticed the part that clips in to the slot the slot is a lot
Longer in length then the part on the actual card is it spose to go somewhere else in the machine

jude1977 wrote on 2026-06-08, 15:30:

Interesting I didn’t know it was a mfm hard drive controller when it’s inserted in my machine it causes the machine not to boot at all is there a reason for this is there Spose to be a ribbon cable attached to

MFM controller cards use the same resource assignments as Primary IDE controller. 😁

wierd_w wrote on 2026-06-08, 17:36:

MFM controller cards use the same resource assignments as Primary IDE controller. 😁

no ide controller in this computer

>it turned on but when i put the 3rd card in it didn't

so does the PC turn on and not boot or not turn on at all with the card? MFM controller has some tantalum caps (big black ones) and one might be shorted, or the firmware (U12) might be corrupted due to age (eproms sometimes do that).

Oh, Silly me, I thought they were inserting it into a newer retro machine for testing.

In this case, maybe there is a collision with some other option rom at D000 , or and IRQ conflict?

hi all thanks for your reply s im needing some more info im wanting to use a hard drive on this machine as it didn't come with one
would any one know where id attache it to, would i attach it directly to the mother board or would i attach it to the mfm card

Use your nose!
Smell the dead card closely.
If you smell that distinctive burnt electronics smell, its easier to find the dead thing.
If you don't, post VERY HIGH resolution/clarity photos here.

It looks pretty clean on the pic above, but it can't hurt to wash it with soap and water.
Water is "the universal solvent" and can fix some shorts.

Dry thoroughly. Full sun 4-5hours recommended.

thanks for the advice ill do that and check it out to see if its ok

hi all Ive finally got my epson 286 pc working Ive even taken out the floppy drives to clean them they work fine the only trouble i had was
i tried formatting one floppy it formatted but gave a message cant use as system disk and when i put it in the floppy drive
it says non system disk or disk error so i tried another floppy disk i had an that formatted without the cant use system disk error message showing up
i then put that disk in the floppy drive and that works fine
my question is why the first disk i formatted came up with that error message and why the second disk i formatted didn't come up with the error message
if anyone knows could you let me know as i have no idea why its happening

Age is enough of a reason.
But just to rule it out, it's not write protected..?

Hi. I've read the thread. I think you need to take a step back. The fact that you have it working to an error message is good. This indicates that power supply and motherboard are working. You should be able to get into the CMOS even if the the battery isn't working. The battery issue can be corrected and should be separate to the errors you are seeing. Epson set up discs don't really do a whole lot other than install dos so you should be able to get by without them. Firstly I think you should check the functionality of your floppy disks, are they any good? Then check the floppy drive. Is it working correctly? On other Epson models they use a standard floppy drive so you should be able to swap it out for a known good FDD.

Many 286 era systems lack a builtin cmos setup program.

Getting to dos from diskette is necessary, so that something like gsetup can be run, instead.

Try a 3 1/2 inch drive in stead of the 5 3/4'' drives

It's true that a 720kb diskette drive (and disk) can be 'treated like' a 360kb diskette drive, by confused bioses.

Even reformatted as 360kb even.

If it came down to that, that *is* a possible option.