386_junkie wrote:

PeterLI wrote:

The PS/2 40 is an ISA machine.

It is... I wonder what they were thinking in the manufacture for this one, possibly an experiment to see how it is taken by the market of the time? Though dropping their own prop bus for the widely used ISA... is not very IBM is it?

I suspect that they needed to have both MCA and ISA in their line of PS/2s simply because the market was predominantly ISA. Getting an ISA based PS/2 meant that people would become familiar with the PS/2 product in general, and IBM was betting that people would simply stick with it and get an MCA based machine next. At least, thats what I've heard over the years...

For what it's worth, both my PS/2 Model 40 and my PS/1 Model 2121 are ISA based. Yay for soundblaster support!

@386_junkie:

Yay! My IBM Model 40SX (2.88 MB Sony) and IBM Modell 30 8088 with 1.44 MB Mitsubishi need new Electrolytic Caps and my 40SX Mainboard also 😀

Greetings

orinoko wrote:

For what it's worth, both my PS/2 Model 40 and my PS/1 Model 2121 are ISA based. Yay for soundblaster support!

Ha... yea, now where did I see that MCA soundcard....

Dubinius wrote:

@386_junkie:

Yay! My IBM Model 40SX (2.88 MB Sony) and IBM Modell 30 8088 with 1.44 MB Mitsubishi need new Electrolytic Caps and my 40SX Mainboard also 😀

Greetings

Greetings,

It sounds like you've got a busy afternoon some day! 🤣

I love to solder... I could do all day, every. Unfortunate that there is no money in it. 😒

All the best with the repairs...

I did the same thing with my PS/2 P70's ALPS drive, but my desktop 70's drive (also alps) seems to not work.
I have another Mitsumi drive that has some mechanical problem, but a solder pad is ripped off from where a cap is supposed to be.
Pics or it didn't happen:

I also fixed one ibm floppy drive, by replacing the caps. Have a other drive that needs new caps, switched out 2 i already had, and the drive started spinning again. Need to by a lot of caps, since i need to repair a few other things.

I do have also ALPS drive on my ibm model 95XP(i guess this is very rare pc as haven't seen anyone sell one..) and now i came conclusion after many tries it just not read disk.
so changing caps is needed.

armankordi please can you tell me the right value for the cap rated 10 ? is it just 10uF?
and there is 3 of 4.7 caps without any polarisation, any tips?
nice job you done on your P70 (also have P70 i guess same thing there is needed to do..)

riku wrote:

I do have also ALPS drive on my ibm model 95XP(i guess this is very rare pc as haven't seen anyone sell one..) and now i came co […]
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I do have also ALPS drive on my ibm model 95XP(i guess this is very rare pc as haven't seen anyone sell one..) and now i came conclusion after many tries it just not read disk.
so changing caps is needed.

armankordi please can you tell me the right value for the cap rated 10 ? is it just 10uF?
and there is 3 of 4.7 caps without any polarisation, any tips?
nice job you done on your P70 (also have P70 i guess same thing there is needed to do..)

Ok, have since bought another drive for the (desktop) 70, and replaced all caps on the board.
Did not work.
About the no polar caps (solid silver ones) for the P70 I ended up just not replacing them, drive functions normal. I've also noticed that some alps drives despite being manufactured in the same year have different designs. The one I bought has some mechanical differences and no doubt electric ones too. Keep your eye peeled, and buy all new caps for the drive just to be safe.
You'll want
3x 4.7uf 16v non polar
1x 4.7uf 25v
1x 10uf 16v
The new drive I bought, also has a weird issue where the motor spins TOO fast, and sometimes doesn't spin.( After I replaced caps)

Can I use standard through-hole electrolytic capacitors instead of aluminium SMDs?

Miphee wrote:

Can I use standard through-hole electrolytic capacitors instead of aluminium SMDs?

Yes, so long as ratings / specifications match, there is no difference as they do the same thing.

Make sure you solder with correct polarity!

I have another faulty ALPS 1,44 drive that doesn't read disks.
I recapped it, cleaned and greased it but still nothing. Head is also clean.
Drive is detected at startup and the head is moving fine but when it comes to booting the head only flinches once, disk rolling continuously, LED stays lit forever and nothing else happens. System also hangs like it's hopelessly trying to read the disk.
I compared it to my other PS/2 drives of the same model, they are 100% identical and nothing is missing. I didn't take apart or modify any moving parts.
I've had a drive before that did this (LED stayed on forever) but recapping worked on that one.
Any tips?