Hi guys, I need your help
My problem right now it's a "whup-whup" or "flup-flup" noise when the mac is turning on. I'm going to tell you the story
I bought a macintosh 512k with a dove MaSnap (scsi and memory) expansion card. I'm an european 220 V user and the Mac Power Supply is 110 V.
I use a transformer from 220 to 110 V (I don't remember but I think that has at least 50 W.)
When I started the Mac the very first time, there's a kind of horizontal lines, so I went directly to resolder the J1 connector (I've fixed 4 or 5 macs with
a similar problem) but there were no success.
Try to reseat the ROM's and the MacSnap memory. No success
I think about swap the logic board with a Plus and test it, buttt...
When I switch on there were a creepy sound, the fuse blow out.When I thought about it, I think that I forgot to change the power supply cable and I plugged in the Mac in a 220 V source.
Sooo, I replace the fuse with a 3 A one (I don't have a 2,5 A) and try to swith on with a 110 v right now.
Disaster.. the analog board began to burn. The Q10 tiristor dissappear, and a lot of resistances were completely burned.
I test the logic board without the Dove expansion in a working Plus and it works ok. Soooo... I replace the following components in the logic board:
R60 1K, R44 100, R45 1k, R46 22 1W, R47 1.5,R48 100,R49 1.5, Q10, Q9, C39, U3, CR28 and CR29 and the four bridge diodes (components characteristics according to Pina's book)
When I swith on again, more burned components...
I replace again the following components:
R60 1K, R44 100, R45 1k, R46 22 1W, R47 1.5,R48 100,R49 1.5, Q10 (the other components seems to be ok) and Q11 this time
When I switch it on, I've heard the flup-flup noise as we start this post.
I follow the Pina's recomendations for a flupping set..
- Check R56 and put it down
- Change C3, C24, C25, C26, C29, C30 and C31
- Change rectifiers CR21, CR5 and CR1
- Change Q8
Nothing...
Finally I resolder:
- Flyback
- Power connector on analog board
- Video Connector
- A lot of suspicious solders..
Nothing...
I don't know How to fix it.. can you help me?? I have the chance to swap the analog board with a plus, but I want to know where the problem is..
Thank you very much for your help!!
My problem right now it's a "whup-whup" or "flup-flup" noise when the mac is turning on. I'm going to tell you the story
I bought a macintosh 512k with a dove MaSnap (scsi and memory) expansion card. I'm an european 220 V user and the Mac Power Supply is 110 V.
I use a transformer from 220 to 110 V (I don't remember but I think that has at least 50 W.)
When I started the Mac the very first time, there's a kind of horizontal lines, so I went directly to resolder the J1 connector (I've fixed 4 or 5 macs with
a similar problem) but there were no success.
Try to reseat the ROM's and the MacSnap memory. No success
I think about swap the logic board with a Plus and test it, buttt...
When I switch on there were a creepy sound, the fuse blow out.When I thought about it, I think that I forgot to change the power supply cable and I plugged in the Mac in a 220 V source.
Sooo, I replace the fuse with a 3 A one (I don't have a 2,5 A) and try to swith on with a 110 v right now.
Disaster.. the analog board began to burn. The Q10 tiristor dissappear, and a lot of resistances were completely burned.
I test the logic board without the Dove expansion in a working Plus and it works ok. Soooo... I replace the following components in the logic board:
R60 1K, R44 100, R45 1k, R46 22 1W, R47 1.5,R48 100,R49 1.5, Q10, Q9, C39, U3, CR28 and CR29 and the four bridge diodes (components characteristics according to Pina's book)
When I swith on again, more burned components...
I replace again the following components:
R60 1K, R44 100, R45 1k, R46 22 1W, R47 1.5,R48 100,R49 1.5, Q10 (the other components seems to be ok) and Q11 this time
When I switch it on, I've heard the flup-flup noise as we start this post.
I follow the Pina's recomendations for a flupping set..
- Check R56 and put it down
- Change C3, C24, C25, C26, C29, C30 and C31
- Change rectifiers CR21, CR5 and CR1
- Change Q8
Nothing...
Finally I resolder:
- Flyback
- Power connector on analog board
- Video Connector
- A lot of suspicious solders..
Nothing...
I don't know How to fix it.. can you help me?? I have the chance to swap the analog board with a plus, but I want to know where the problem is..
Thank you very much for your help!!
