commodore 4016-n with extreme water damage

[rorypoole]

what is this?

what is this?

what is this? its between the mains and the transformer, the rusty cylinder is filled with epoxy, so if its ok I will clean it and sealed with epoxy.
I looked it up and a rusty transformer is ok? the valve amp guys use them, strangely the rust makes the transformer more efficient! so I will clean it up and seal it with wood varnish and epoxy.

 

[rorypoole]

need ECR for capacitor

need ECR for capacitor

I have a 31 year or older cap, its 22000 mfd / uf 0/+50% 16v, its a roe elko eym/a din 41250 -40 to 85oC 427/5.81 made in w-germany!
I need a 1980~ data sheet so I know the old caps ESR as moden capacitors have a much lower ESR and will burn out the diodes and stran the transformer, I can fit a moden cap and a resister in series to make it work like the old one.
the commodore schematics have very little info on the caps used.

 

[rorypoole]

I am going to get the case and visible faults fixed, fit some fuses and over voltage protection in the psu, and get it working, then I will upgrade the video and system ram, then add a 40 / 80 column switch, find or build a high resolution 512 x 512 graphics card for it, then start programing it to use the graphics card.

 

[rorypoole]

the main board is a universal 80/40 8032080

the main board is a universal 80/40 8032080

the main board is a universal 80/40 8032080 that can be easly upgraded from 40 col 16k ram to 80 col 32k ram, the main board also has 254682 on the lable?
the board needs some tlc, it needs the damaged resistors replacing and all the IC sockets replacing and all the caps and old and lumpy!!! and need replacing.
the main board was coverd in rust oil and mold!! but I washed it and it looks ok, it took 4h, the keyboard was full of mud in the plastic tube bits, it took 3h to clean!

 

[dave_m]

I can fit a moden cap and a resister in series to make it work like the old one.

Rory,
With all the issues I see from your photos, the ESR of the replacement cap is the least of them. :smile:

But this is a great attempt that you are doing. If you make enough progress to need a replacement set of ROMs, I will send you a programmed set of 2532 EPROMs to use, gratis. They are direct replacements for the Commodore ROMs. I really admire your effort.

If the ROMs and RAMS all turn out to be non functional, you may want to consider using a PETVet, which is a little board that plugs into the 6502 CPU socket, to bypass them altogether.

Best wishes with your project,
Dave

 

[rorypoole]

main board after a good clean

main board after a good clean

much better now, I am spried how will the board came up! I thort is was junk

 

[rorypoole]

Rory,
With all the issues I see from your photos, the ESR of the replacement cap is the least of them. :smile:

But this is a great attempt that you are doing. If you make enough progress to need a replacement set of ROMs, I will send you a programmed set of 2532 EPROMs to use, gratis. They are direct replacements for the Commodore ROMs. I really admire your effort.

If the ROMs and RAMS all turn out to be non functional, you may want to consider using a PETVet, which is a little board that plugs into the 6502 CPU socket, to bypass them altogether.

Best wishes with your project,
Dave

I have thort about the PETVet, it could be useful to get it working but I want the system board to be fully working and withe the PETVet I could not fit the graphics card in!, and thanks for the offer for the eproms, but I an not there yet, lol

 

[dave_m]

Make sure you dry out the board, water vapor is the enemy of printed circuit boards.

 

[dave_m]

I have thort about the PETVet, it could be useful to get it working but I want the system board to be fully working and withe the PETVet I could not fit the graphics card in!

Yes, it could be used as a tool to find out what is not working on the main board to help troubleshooting.

 

[rorypoole]

need crt pcb schematics

need crt pcb schematics

I cant find crt pcb schematics for the 4016?, the pcb has lots of corroded diodes and old electrolytic caps and a rusty mystery transistor?
any one know whare I can get the CRT schematic?

 

[crock]

I cant find crt pcb schematics for the 4016?, the pcb has lots of corroded diodes and old electrolytic caps and a rusty mystery transistor?
any one know whare I can get the CRT schematic?

Here : http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/8032/index.html

 

[rorypoole]

Make sure you dry out the board, water vapor is the enemy of printed circuit boards.

I know, I will dry it out for a week min before I power it up

 

[rorypoole]

Here : http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/8032/index.html

thanks for the link, its the one!

 

[rorypoole]

petvet

petvet

what do they cost, can you get it as a kit?

 

[crock]

what is this? its between the mains and the transformer, the rusty cylinder is filled with epoxy, so if its ok I will clean it and sealed with epoxy. I looked it up and a rusty transformer is ok? the valve amp guys use them, strangely the rust makes the transformer more efficient! so I will clean it up and seal it with wood varnish and epoxy.

It's a line filter. Old ones have a nasty habit of exploding in a rather spectacular way so I remove them on the advice of others with no ill effects.

Re: PETVet : what do they cost, can you get it as a kit?

Not sure Mike has the prices on his site but yes, you can get it as a kit. Main link here : http://www.bitfixer.com/bf/petvet

 

[rorypoole]

so its probably some caps in a tube! just like old valve radios, lol
I would like to put a replacement in, its not on the circuit diagram?
the 8032 has a filter in the power connecter

 

[MikeS]

I want to have copes of all the roms on fusible-link prom...

You won't find compatible PROMs; it's either original Commodore ROMs, 2532 EPROMs, or 27/28xxx (E)EPROMs in an adapter (or a PETvet of course).

But as mentioned, in practice EPROMs should be just as reliable as the ROMs.

What's that saying about where angels fear to tread... ;-)

 

[rorypoole]

I dont what you mean about angels? but what about proms in a adapter? I will probably have to make an adapter that will hold the 80 and 40 col roms so it can be switched

 

[MikeS]

I dont what you mean about angels? but what about proms in a adapter? I will probably have to make an adapter that will hold the 80 and 40 col roms so it can be switched

PROMs don't come in those sizes, aside from the fact that they are getting very hard to find and would probably be 30 years old as well even if you could.

Why so determined not to use EPROMs?

You don't really need an adapter to switch between the 40 & 80 column (EP)ROM; just lift one pin (or sandwich an IC socket with that pin bent out between the IC and its socket).

More pressing matters first though...

 

[rorypoole]

eproms aging, bit rot

eproms aging, bit rot

from looking on google eproms hold there data for 10 to 25 years, but I think it could be extended by reading the code in the roms, if its ok rewriting the old code back to the eprom?