At wit's end with a Plus - odd behavior after recap

[lostkerbal]

Hi,
I've recently completed a recap of my '86 Mac Plus; After recapping, I noticed that it wouldn't boot from my BlueSCSI, but it otherwise seemed perfectly fine (flashing disk on startup, mouse moves, etc.), so I ordered a floppy to boot from. After receiving and testing said floppy, it initially got to "Welcome to Macintosh", at which point the borders of the rectangle containing the welcome text began to flash. The next boot attempt, it just sat at a static "Welcome to Macintosh" screen for 5 minutes straight, then went to "a system error has occurred" and prompted me to restart. After trying that a few more times, it stopped chiming and showed Sad Mac 0380D0, and the diagonal lines on power-up started to become corrupted. Then, it started chiming again, but showed a similar Sad Mac. This is my first big retro Mac project, but I did not expect it to be this difficult. Any and all help is greatly appreciated.

 

[cheesestraws]

Sad Mac 03.... is a memory error, which is consistent with your other symptoms here. When you recapped it, did you remove the RAM? It might be worth checking that all the connectors are clean and unoxidised - another good test to do here would be to shuffle the SIMMs into different slots and see if the error moves.

 

[lostkerbal]

Sad Mac 03.... is a memory error, which is consistent with your other symptoms here. When you recapped it, did you remove the RAM? It might be worth checking that all the connectors are clean and unoxidised - another good test to do here would be to shuffle the SIMMs into different slots and see if the error moves.

I'll do that next; it's strange, the computer was working almost perfectly before the recap, it just started to not turn on due to a power issue.

 

[dv-]

I recently recapped two Plusses and had similar issues; for whatever reason(s) I needed to spray contact cleaner on the ram sockets and clean the contacts on the SIMMs for both of them before they’d work reliably again, despite not having touched the RAM.

Was weird. I just chalked it up to gremlins and dirt.

Did you recap the logic board too or just the analog board/PSU?

 

[lostkerbal]

Just the analog board; what's a place I could get some contact cleaner? My local hardware store doesn't carry it.

 

[Reasons.]

Auto supply stores will have it. Can also pick up dielectric grease for the anode cap.

 

[JC8080]

You can also try removing and re-seating the SIMMs even if you don't have contact cleaner. If your SIMM sockets have the plastic clips holding the SIMM in, be very gentle or those can break. Just moving the machine around could have jostled something and caused a poor connection.

 

[falen5]

Clean and reseat anything that is removable

If you have the plastic tabs holding the memory simms in place , use a hair dryer of something to warm the plastic a bit before bending them back to release the sims - warm them , dont melt everything !

when out use a pencil eraser ( chunk of rubber ) to gently wipe the contacts ( if you dont have contact cleaner ) - cleans them up good

clean the entire logic board - I just wash them all is warm soapy water , rinse the hell out of them , dry them off with said hair dryer and leave them overnight to make sure they are 100% dry

taking out 128 mb ram from an se/30 - all with the plastic tabs - watch 26:59 -

the mess on the board , washing , and the cleaned board is at 38:09 on same vid

cleaning memory sims with a rubber - watch 2:36 from here -

This is what I do anyway , was advised on here , and its worked every time

Still may not be your problem - sounds like bad memory - but at least youll know its not dirt



all these machines need a good clean , and they deserve it , to make them last ......... a bit of TLC for iconic bits of history

 

[lostkerbal]

Thank you guys very much for the advice, I'll try that the next opportunity I get to work on it.

It's weird, too, since I took the RAM out to have a look at the contacts and they seemed fine, as well as reseating both of the ROM chips. I might have messed it up, who knows. When taking out one of the ROM chips, one of the legs got bent, but I realigned it with the tip of a mechanical pencil, and it seems to be working fine.

 

[dv-]

Thank you guys very much for the advice, I'll try that the next opportunity I get to work on it.

It's weird, too, since I took the RAM out to have a look at the contacts and they seemed fine, as well as reseating both of the ROM chips. I might have messed it up, who knows. When taking out one of the ROM chips, one of the legs got bent, but I realigned it with the tip of a mechanical pencil, and it seems to be working fine.

A bent/unbent pin or two shouldn't be a big deal. If the ROM chips were bad I don't think you'd even get the sad mac.

Contacts can look fine and still have some scum on them causing problems. (I don't know why but dust seems to trap grease in certain environments and create a sort of slime. Computers used by smokers are also notorious for this.)

Or the little pins in the socket might be slightly bent causing intermittent contact with the pad on the SIMM. (Maybe try one pair of SIMMs at a time to isolate the sockets?)

Cotton swabs and rubbing alcohol are also pretty handy for cleaning almost anything. I wouldn't use them on the sockets (The pins would just snag the cotton and make a mess) but it would do a fine job of cleaning the SIMM.

 

[lostkerbal]

A bent/unbent pin or two shouldn't be a big deal. If the ROM chips were bad I don't think you'd even get the sad mac.

Contacts can look fine and still have some scum on them causing problems. (I don't know why but dust seems to trap grease in certain environments and create a sort of slime. Computers used by smokers are also notorious for this.)

Or the little pins in the socket might be slightly bent causing intermittent contact with the pad on the SIMM. (Maybe try one pair of SIMMs at a time to isolate the sockets?)

Cotton swabs and rubbing alcohol are also pretty handy for cleaning almost anything. I wouldn't use them on the sockets (The pins would just snag the cotton and make a mess) but it would do a fine job of cleaning the SIMM.

Yeah, I gave the whole board a wash with 80% IPA and let it dry for 4 days, as well as spot cleaning the sockets. It's just so weird that both the analog and logic board look pristine.

 

[cheesestraws]

Yeah, I gave the whole board a wash with 80% IPA and let it dry for 4 days, as well as spot cleaning the sockets. It's just so weird that both the analog and logic board look pristine.

When you start moving things around, things that were hanging on by the skin of their teeth get disconnected or finally break or whatever. It's just the way of things - you're putting a different kind of stress on things, after all.

(quick check: when you recapped the AB, did you also reflow the solder on the back of the AB <-> LB connector and the other big KK396 connectors? They're very prone to getting solder cracks in them that can produce extremely strange symptoms - I don't think that's what's going on here, but I wouldn't absolutely rule it out)

 

[cheesestraws]

rinse the hell out of them

'scuse the double post - quick tip - if you rinse with isopropanol after your water washing steps (or do your isopropanol washing after your water wash) then two helpful things happen:

1. any remaining water that comes into contact with the isopropanol, its surface tension is considerably reduced, which will help it get out from underneath components and
2. the mixture of water and isopropanol evaporates more readily than water on its own, so the board also dries quicker.

of course, if you're intending to use a hair dryer, it's probably a good idea to rig up lots of ventilation so you don't end up breathing in isopropanol vapours...

 

[falen5]

love the smell of iso in the morning !

after i wash a board i go outside , take a good hold on the board and swing it , as if you are swinging a tennis racket

do that a few times as fast as you can and it gets most of the water off the board

last thing i do is a wash in iso then , swing it a few times , then dab off the rest with some tissue

go over it with a hair dryer and leave it in a hot press for the night

 

[lostkerbal]

When you start moving things around, things that were hanging on by the skin of their teeth get disconnected or finally break or whatever. It's just the way of things - you're putting a different kind of stress on things, after all.

(quick check: when you recapped the AB, did you also reflow the solder on the back of the AB <-> LB connector and the other big KK396 connectors? They're very prone to getting solder cracks in them that can produce extremely strange symptoms - I don't think that's what's going on here, but I wouldn't absolutely rule it out)

I double-checked all visible connections and reflowed both ends of all of the large connectors in the computer, then triple-checked for short-circuiting.

 

[JC8080]

'scuse the double post - quick tip - if you rinse with isopropanol after your water washing steps (or do your isopropanol washing after your water wash) then two helpful things happen:

1. any remaining water that comes into contact with the isopropanol, its surface tension is considerably reduced, which will help it get out from underneath components and
2. the mixture of water and isopropanol evaporates more readily than water on its own, so the board also dries quicker.

of course, if you're intending to use a hair dryer, it's probably a good idea to rig up lots of ventilation so you don't end up breathing in isopropanol vapours...

Using 99% IPA (or 100% if you can find it) will speed up drying faster than 80% IPA. Since it has so little water it leaves very little behind when the alcohol evaporated.

 

[cheesestraws]

Using 99% IPA (or 100% if you can find it) will speed up drying faster than 80% IPA. Since it has so little water it leaves very little behind when the alcohol evaporated.

Absolutely. 99%/100% is the norm over here, I keep forgetting that in some places it isn't. Thanks!

 

[LaPorta]

Absolutely. 99%/100% is the norm over here, I keep forgetting that in some places it isn't. Thanks!

Depends on what it is. If you visit your corner drug store, they mostly carry 70% for cuts and scrapes and such. Sometimes why will have 91%, too. You need a specialty store/Amazon for 99%

 

[lostkerbal]

Cleaned all the SIMM contacts (contact cleaner before and after rubbing with eraser), SIMM slot pins (contact cleaner), ROM chips and board interconnect, still the same results; it just flashes no disk with a BlueSCSI, and if I try the System 6.0.8 disk, it very slowly gets to "Welcome to Macintosh", then says a system error occurred due to illegal instruction. What now?

 

[dv-]

Do you have other ram to try? Or can you try the existing ram in pairs? (2MB at a time?)