Double confirm does pay isn't it? 😉 Congrats.

Oxidation on the contacts/gold finders is quite common on retro hardware. Usually a rub with a pencil eraser and/or a few insertion and wiggling will solve the problem.

kalohimal wrote on 2020-07-26, 04:15:

Double confirm does pay isn't it? 😉 Congrats.

Oxidation on the contacts/gold finders is quite common on retro hardware. Usually a rub with a pencil eraser and/or a few insertion and wiggling will solve the problem.

Yeah its odd isn't it?
I had removed all these chips and cleaned down the board with parts cleaner to begin with but looks like i will need to again after soldering back the new caps. Onky half a dozen anyway.

Would be good to try and identify the make of board now that it works.

Its got a very basic bios. Its a pheonix.

Cpu feels hot too. What is a normal running temp of a 286?

Feels about the same as my 486 dx 33

nzoomed wrote on 2020-07-26, 04:26:

Cpu feels hot too. What is a normal running temp of a 286?

It's normal, they get very hot. With some thermal tape you can install a small heatsink on it to extend it's lifespan.

Doesn't look like your BIOS has an ID string. 286s are at very early stage of PC so perhaps they have not started implementing it.

Wow! That is great ! So you do have a ISA slot that may have corrosion or just standard air junk and needs cleaning since the vid card did not work in it. Use a matchbook cover with ISA alc is the easiest way. You probably should go over all the socketed chips and press firm on them to make sure they are well seated. Then boot it back up to make sure.
Good job ! I am sort of thinking stupid cause I did not ask if you had a speaker attached.... that would have revealed a video issue.
Yes some 286 cpu run hot, AMD's and Intels being the worst, Harris and Seimens being the coolest running.

Miphee wrote on 2020-07-26, 04:33:

nzoomed wrote on 2020-07-26, 04:26:

Cpu feels hot too. What is a normal running temp of a 286?

It's normal, they get very hot. With some thermal tape you can install a small heatsink on it to extend it's lifespan.

Sweet, that's good to know.
This is a 10mhz 286. I think this is almost the fastest speed intel made them in.

I see there is a socket for a 287 co processor and a provision for a 24mhz crystal.

Is all thats required is to install the crystal and processor?

Also looking at what the best option is regarding replacement of the CMOS nicad battery.

No provision on this board for a non rechargeable.

kalohimal wrote on 2020-07-26, 04:34:

Doesn't look like your BIOS has an ID string. 286s are at very early stage of PC so perhaps they have not started implementing it.

All I see on the screen is CEC286.

Is that any use?

Horun wrote on 2020-07-26, 04:38:

I am sort of thinking stupid cause I did not ask if you had a speaker attached.... that would have revealed a video issue.

I think it's because we're all too focus on trying to find the short 😂

Horun wrote on 2020-07-26, 04:38:

Wow! That is great ! So you do have a ISA slot that may have corrosion or just standard air junk and needs cleaning since the vid card did not work in it. Use a matchbook cover with ISA alc is the easiest way. You probably should go over all the socketed chips and press firm on them to make sure they are well seated. Then boot it back up to make sure.
Good job ! I am sort of thinking stupid cause I did not ask if you had a speaker attached.... that would have revealed a video issue.
Yes some 286 cpu run hot, AMD's and Intels being the worst, Harris and Seimens being the coolest running.

Yeah I think I will go over all the sockets with deoxit!
I did actually install a speaker after guessinf the correct connector and it gave a beep error so I tried a different isa slot.

I still need to try and figure out if there is a turbo switch connector and find the power led connector next on the list.

Never had much experience with a 286 before so had no idea on how hot they got.

I also have the mfm hdd and controller card which will be fun to see if I can get working. Might have a bunch of dosgames on it too, I know I've found a few old drives that do.

Any idea where the connectors would be for the turbo switch, reset and power led etc?

I found the speaker connector but have no idea where the rest go and don't want to damage anything.

nzoomed wrote on 2020-07-26, 04:26:

Cpu feels hot too. What is a normal running temp of a 286?

It Feels about the same as my 486 dx 33

The first 286s use NMOS. Later 286 CPUs switched to CMOS and use quite a bit less power (and ran cooler). I doubt the heat would be a problem, but if it bothers you, you could always swap in a CMOS version. However, as your board uses the less common LCC package you are out of luck. It seems the low power versions were only made for PGA and PLCC. I suppose you could change the CPU socket if you really wanted.

nzoomed wrote on 2020-07-31, 20:20:

Any idea where the connectors would be for the turbo switch, reset and power led etc?

I found the speaker connector but have no idea where the rest go and don't want to damage anything.

Let me guess: the 4 pin near edge of board by the 80c42 KB controller ? I have an odd ball 286 that has the Turbo connector in an odd spot very similar to where your J5, J7 and J13 are but on mine is only two headers: Turbo switch and Turbo LED, you have three and if you short the wrong one it could be disastrous. Have you check with NSSI or other util to see what speed it is running ? Some boot at Turbo w/o switch being on, others need the switch or a keyboard combo to turn it on. Note J13 has a + next to one pin so it could easily be an LED header. Added: you could use a resistor as a jumper with say 1k ohm, that would limit the I to 5mA (if 5v, use a DVM to check Volts between pins on both J5 and J7) . That should not hurt and is not the same as a jumper or switch... just a thought.

Horun wrote on 2020-08-03, 01:41:

nzoomed wrote on 2020-07-31, 20:20:

Any idea where the connectors would be for the turbo switch, reset and power led etc?

I found the speaker connector but have no idea where the rest go and don't want to damage anything.

Let me guess: the 4 pin near edge of board by the 80c42 KB controller ? I have an odd ball 286 that has the Turbo connector in an odd spot very similar to where your J5, J7 and J13 are but on mine is only two headers: Turbo switch and Turbo LED, you have three and if you short the wrong one it could be disastrous. Have you check with NSSI or other util to see what speed it is running ? Some boot at Turbo w/o switch being on, others need the switch or a keyboard combo to turn it on. Note J13 has a + next to one pin so it could easily be an LED header. Added: you could use a resistor as a jumper with say 1k ohm, that would limit the I to 5mA (if 5v, use a DVM to check Volts between pins on both J5 and J7) . That should not hurt and is not the same as a jumper or switch... just a thought.

I was wondering the same thing, but too afraid to connect anything up incase i get smoke.
I will put a multimeter on the pins and probe around a bit to see what voltages I get. Good spotting on the + next to j13, i didnt see that.
NSSI looks a good program to try out, ive never heard of it before.
I have put this baord aside for the time being as I dont have a case that fits it! Its about 20mm too long and it hits mounting posts that are welded to the chassis that hold the drive bays.