HELP WITH MACINTOSH PERFORMA 200 BOOT UP

[ROLLERMANZ]

Hello Guys,

I have a Macintosh Performa 200, it has a good power supply, Hard drive, CRT.. everything is okay with it except the logic board. 

The logic board has leaking capacitors, I have replaced them all with good quality ones, the motherboard has been soaked in battery distilled water for a whole night and cleaned thoroughly. the ram and SIMMS chips have been re-seated properly. even after doing all this, when the macintosh is fired up, it only shows scrambled black and white vertical lines with no start up sound. i have left this macintosh turned on for a while to see if it actually came back to its normal system display but it just stays like that forever. I have also heated the motherboard on a very low heat range with a heat gun to make sure all the solder joints are refreshed. 

everything I could think off and found on the internet has been done with it but its still not come back to its normal lifestyle. 

I have even also tried different RAM chips to see if thats the case but its still not helped.. what I am suspecting is that maybe the SIMMS chips are whats fiddling about. Do you guys think thats the case? I don't see any other issue with the logic board.. even if it was any solder joints, that would've been correct with the heat gun.. i really think its the SIMMS chips..

You must be think if i know the problem then why am i posting this issue here, the thing is i am not quite sure what SIMMS chips i can replace this with.. I have a working macintosh classic ii, SE, Macintosh Plus... 

your help would be really appreciated. 

THANK YOU in advance

See the images attached.. 

View attachment 4897

View attachment 4898

 

[Elfen]

Was the board washed before or after the caps were replaced?

And the electrolytic can caps on the board, you replaced those or those were original, and were they washed?

If you soaked the board with those caps on the board, then they have shorted out and needs to be replaced. 24 hours for a board washing is too long, and could have shorted out those caps. A washing should be 10 - 15 minutes, a 1/2 hour tops. Then after washing, the water should be chased out with acetone and alcohol and then blown dry with compressed air (best) or a hair blow dryer set to high.

Also, remove the ROMs from the socket and look at sockets and blow dry that.

 

[ROLLERMANZ]

Yeah the motherboard was washed with the capacistors removed :. I did dry it up with a fan left on it for 2 hours and then with a blower and a heat gun.. So no chance of it being still wet.. I removed the ram and SIMMS chip plus the battery aswell

 

[360alaska]

I dishwashed my P200 board, then rinsed it with purified water, then put it on a piece of cardboard and put it in the over for 2 hours at 200F. 

 

[Elfen]

Water can still be in there, like under the chips where space is tight. Alcohol can chase the water out, but I'm thinking what other damage a drowned board can have. These are 4 to 6 layer boards, and this can have other issues like the board pulling itself apart at the seams from the water that seeped in between the microscopic cracks, or traces broken as the board expanded while it was going out for a long swim.

360alaska has a good idea but I do not know if this late in the game it would work for you. Best you can do it try it out.

 

[Byrd]

The logic board has leaking capacitors, I have replaced them all with good quality ones, the motherboard has been soaked in battery distilled water for a whole night and cleaned thoroughly. the ram and SIMMS chips have been re-seated properly. even after doing all this, when the macintosh is fired up, it only shows scrambled black and white vertical lines with no start up sound. i have left this macintosh turned on for a while to see if it actually came back to its normal system display but it just stays like that forever. I have also heated the motherboard on a very low heat range with a heat gun to make sure all the solder joints are refreshed. 

Hi Rollermanz, I'm not sure where you got this advice but I reckon you've hosed the board (literally, sorry to say!) by sitting it in water for hours on end.  Any water used to "wash" a PCB should be promptly taken away then allowed days of drying time to properly remove any remnants left behind.  Personally I don't like the "wash" method unless you have nothing to lose, I'd prefer to manually clean the board using isopropyl alcohol wipes/spray with the idea that it'll quickly evaporate once any capacitor goo has been removed.

Also using a heat gun at very low heat range isn't going to do a thing to "refresh" solder I'm sorry to say.

JB

 

[ROLLERMANZ]

I forgot to mention that I first took the old leaky capacistors off and put the new ones on, i then tried it on and it showed the scrambled vertical lines .. So i thought maybe washing it up would be a good idea .. So this shows that soaking it in water didnt make it any worse, its jus been the same ..before i washed it up, i tried it on with new capacistors and tried it after washing with the same capacistors ..

Also i have soaked around 8 motherboards in the past and they all worked fine this way .. And always dried them up with a blower and a fan for hours .. It always worked out like that

 

[Macdrone]

Ok. Look for bad traces, may need to check for point to point continuity.

Goo can eat right through them. Also look for uniservers thread and make sure polarity is correct. Some silks teens have been found to be incorrect.

Reseat any chips that are socketed as corrosion can cause issues also.

 

[beachycove]

Will it boot up properly with the RAM removed?

The other obvious question would be whether the recap was done right, but it sounds like you know what you are doing in that department.

 

[ROLLERMANZ]

I just tried it with the RAM chips removed, but it still shows the same vertical lines screen.. I am sure its the SIMMS CHIPS.. Do you guys not think so ??

 

[Macdrone]

Well in your photo after recap there looks to bet "wet goo" spots in the areas by the capacitors.  

Its kind of the reason we keep mentioning caps.  i have had to use needles and screwdrivers to scrape some of it off from years of leakage.

 

[Denus]

When you're use a distilled water bath, do you add a base (ammonia) to it to neutralise the acid?

Water only will not remove the dried acid on the print board that easily. A warm bath is also working much better than a cold one.

After the bad, an air duster can, or even a bicycle air pump (with a balloon valve for example) can be used to chase the water that stays under the chips, ROM sockets, CPU and the expansion slot.

I had very good results with these methods.

 

[360alaska]

Just bake it dude!

 

[ROLLERMANZ]

There are no marks of water, whats on the board looking like water is some bits of the flux nt water .. But water wouldnt show scrambled screen.. Im quite sure its the SIMMS.. How can i sort out the SIMMS CHIPS.. Thanks

 

[Macdrone]

have not seen bad chipson these.

Bad traces, bad solder joints, left over goo, left over flux and pins that are disconnected due to rot from goo.

 

[Elfen]

Like 360alasks says, "bake it." But also look at ever trace with a magnifying glass and visually inspect the board! See it there are bad/rotted traces, pads and connections. Check with a multimeter, even a good looking trace could be bad. Fix what you find.

 

[ROLLERMANZ]

So how long should i bake it for?

 

[Macdrone]

10 min at 400 when I do mine then shut off and open door to air cool slowly.

 

[ROLLERMANZ]

Okay