Mac Classic/Performa200 startup fault - suggestions pls

[Interceptor2]

Hello - I have a Performa200 that upon start up does as shown in pik (I've stolen this pik from elsewhere but looks exactly the same but the guys there didn't have a solution)



The boards is: 820-0326-B it has two SHARP chips in U22 (341-0257)and U23 (341-0261) marked as "128k & 256k" in DIL skts and had 2 memory simms installed (HYM594000M).

In the fault finding process I have removed, cleaned and replaced all the above chips but the fault continues, so I have removed the chips (all of above) disconnected any drives (floppy and HD) checked the power supply (5V) and still the fault persisits. So the guess is there is a fault on the main board. There is no battery installed or goop spillage, all the caps look OK, the fuses seem intact, the two reset buttons seem in order too.

I'm out of ideas! Suggestions please!

 

[Paralel]

Looks like classic Simasimac to me.

 

[Interceptor2]

"1. SimasiMac (Horizontal Stripes)" - taken from the Japanese Mac fix site - but I failed to add, ahem.. there is no battery in the thing, does this model fail to boot if there is no battery??

 

[Paralel]

Nope. Mine has no battery and it works just fine.

Re: stripe pattern, I've seen Simasimac represented by both horizontal and vertical stripes. Same solution, cleaning the logic board, worked every time.

 

[Interceptor2]

IT WORKS!! I cleaned the board in alcohol and then replaced all the E.caps, very fiddly and it now works. The cap goo is almost invisible, I only really noticed it in the murk of the clear alcohol, the soldering job is not for the faint hearted it does require very good soldering skills else the board can get ripped to pieces.

 

[Mac128]

The cap goo is almost invisible, I only really noticed it in the murk of the clear alcohol, the soldering job is not for the faint hearted it does require very good soldering skills else the board can get ripped to pieces.

Yup that cap goo is a sneaky problem. That's why the dishwashing method is 99.9% effective as it tends to get any goo you might miss by hand cleaning, or even submerging the entire board in an alcohol bath. Hopefully you got all of yours, because if any is left to fester it will ultimately corrode traces, and then you have bigger problem.

The soldering issue is exactly why I gave up on vintage computer collecting past the SE. I simply don't have the time or patience, nor the dedicated equipment to work with SMD caps (or any component for that matter), nor am I interested in taking it to that level. Thankfully, Mini vMac does just about anything the actual Classic can do, including boot from the embedded ROM System. If my Color Classic finally goes down, it will likely become an iPad stand or Mac Mini conversion project, simply because I love the form factor. My Classic II logic board has cap failure, so debating what to do with it.

 

[Interceptor2]

My Classic II logic board has cap failure, so debating what to do with it.

- give it me! I'm now an expert... ahem.. and have a Classic II without a mainboard!