Jump to content


Photo

Mac Plus Horizontal Line and Speaker Noise Boot Issues

Mac Plus Lines Boot Horizontal Noise

  • Please log in to reply
8 replies to this topic

#1 MacinPosh

MacinPosh
  • 6502
  • LocationSheffield, UK

Posted 08 July 2017 - 04:22 PM

Good afternoon all,

 

I have acquired two Mac Plus units of which neither want to boot.

 

I've started with the usual logic and analog board cleaning and recapping to no avail.

The most promising combination of boards only achieves a white horizontal line accompanied by noise from the speaker, as seen in this video:

 

Other combinations of board only achieve a flupping noise at various speeds with a blank screen.

 

Nothing seems particularly broken on any of the boards, except scorching underneath the 5W 1Kohm resistor on both of the analog boards, both of which tested open and have subsequently been replaced.

 

I know there are a lot of variables at work here and not having a working system to swap parts and narrow down the problems makes it more difficult to diagnose, but are there any specific areas that need checking/replacing to start off?

 

Thanks 



#2 just.in.time

just.in.time
  • 6502

Posted 08 July 2017 - 04:40 PM

I vaguely remember the classic repair guide mentioning something about the white line issue.

 

If you haven't already, give this a browse.  Maybe it will have some insight or suggestions:

http://www.ccadams.o...classicmac2.pdf



#3 BadGoldEagle

BadGoldEagle
  • 68000

Posted 08 July 2017 - 06:12 PM

According to Larry Pina's The Dead Mac Scrolls, which you can download here...

 http://maccaps.com/M...Mac Scrolls.pdf

(Thanks again Uni for preserving those books by the way, in case you're reading this! Which I doubt but still...)

 

 

... There could be multiple causes to your multiple problems (yep that sucks all right)

 

Pages 49 and 50 cover the display issue. Of course if that doesn't work, bad caps* could still be the culprit. 

 

About that sound issue: Again, multiple things could have gone wrong, I suggest trying first if the audio on the logic board is corrupted as well.

 

The Flup Flup Flup thing is most probably caps*, again. (see pages 24 through 27 of the book for a more detailed diagnosis).

 

 

* Someone on this forum listed the caps for the euro version of the analog board (220V, yes the caps are apparently slightly different) but I can't find the link to that thread right now. I need to recap mine as well, it has a similar issue: the line's vertical not horizontal in my case.


COOL STUFF: Working original & nearly complete 1984 Macintosh w/ Picasso kit, still looking for a G440 mouse :p, NIB Newton MessagePad from 1993, iMac G3 400MHz DV Graphite

IN THE WORKS: The outstanding SE/30 (50MHz Powercache, Pivot Display Color Graphics) but also non-working 512K Hyperdrive w/ Manuals & Disks, Mac Portable M5126, SE Dual 800k, Classic II, HD40SC, Apple Djinn... I have a lot of restorations going on!


#4 BadGoldEagle

BadGoldEagle
  • 68000

Posted 08 July 2017 - 08:04 PM

Oh, here it is! Found it! From here

 

Macintosh Plus Analog Board (International version 230 volts)

- 4x 2200uf, 16v Radial: D=18mm, H=35mm
- 1x 4700uf, 16v Radial: D=18mm, H=35mm
- 1x1000uf, 16v Radial: D=16mm, H=25mm
- 1x 220uf, 16v Radial: D=10mm, H=20mm
- 2x 470uf, 10v Radial: D=8mm, H=12mm
- 2x 22uf, 50v Axial: L=16mm
- 1x 47uf, 16v Axial: L=14mm
- 1x 33uf, 16v Axial: L=13mm
- 2x 4700pF, 250v Box: L=13mm
- 1x 474K, 400V Metal Poly: L=23mm
- 1x 3.9uf 35v Bi Polar: D=18mm, H=35mm


COOL STUFF: Working original & nearly complete 1984 Macintosh w/ Picasso kit, still looking for a G440 mouse :p, NIB Newton MessagePad from 1993, iMac G3 400MHz DV Graphite

IN THE WORKS: The outstanding SE/30 (50MHz Powercache, Pivot Display Color Graphics) but also non-working 512K Hyperdrive w/ Manuals & Disks, Mac Portable M5126, SE Dual 800k, Classic II, HD40SC, Apple Djinn... I have a lot of restorations going on!


#5 bibilit

bibilit
  • 68000
  • LocationParis area -FRANCE-

Posted 09 July 2017 - 07:04 AM

Flup Flup is Analog Board related.

 

Most of the times the culprit is the optoisolator.


Macintosh Classic and II ,CC, SE, SE/30,IIsi 25mhz(RasterOps video),Q 700,LC, LC III,LC475, PBook Wallstreet/Bronze/5300cs/1400c/100/Tibook Imac G3 slot-in, Bondi and G4 / PMac G4 sawtooth, QS, MDD, Yikes!, Cube, Imac Core 2 Duo, Ibook G3 (white/clam) G4 + Newton 120, eMate 300,Quicktake 150,  PowerCD


#6 MacinPosh

MacinPosh
  • 6502
  • LocationSheffield, UK

Posted 09 July 2017 - 06:55 PM

These are all great suggestions. I'll order up and replace parts sequentially and post my results ASAP

 

Thanks 



#7 MacinPosh

MacinPosh
  • 6502
  • LocationSheffield, UK

Posted 26 July 2017 - 08:22 PM

I've finally got round to looking at these Pluses, and interestingly/unfortunately the analog boards are working fine as they boot up the logic board borrowed from a working plus just fine. 

 

Larry Pina suggests the 5v regulator or the TSM chip is to blame for logic board related flupping. I've tried replacing both of these with no success.

Are there any other "usual" suspects or is it a case of checking for bad traces? Swapping ROMs and RAMs doesn't seem to help either  xx(

 

Thanks 



#8 CharlieFrown

CharlieFrown
  • 6502

Posted 26 July 2017 - 08:35 PM

looks like vertical synchro issue, I wouldnt keep it powered on.


Edited by CharlieFrown, 26 July 2017 - 08:35 PM.


#9 BadGoldEagle

BadGoldEagle
  • 68000

Posted 26 July 2017 - 09:45 PM

Hummm... 

It could be a cracked solder joint on the logic board connector (LB side of course...)? That can happen. 

It certainly won't hurt to replace the old solder with fresh one. (Reflowing sometimes doesn't work)


COOL STUFF: Working original & nearly complete 1984 Macintosh w/ Picasso kit, still looking for a G440 mouse :p, NIB Newton MessagePad from 1993, iMac G3 400MHz DV Graphite

IN THE WORKS: The outstanding SE/30 (50MHz Powercache, Pivot Display Color Graphics) but also non-working 512K Hyperdrive w/ Manuals & Disks, Mac Portable M5126, SE Dual 800k, Classic II, HD40SC, Apple Djinn... I have a lot of restorations going on!






Also tagged with one or more of these keywords: Mac, Plus, Lines, Boot, Horizontal, Noise

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users