Apple II Europlus - issues with video

11 posts / 0 new
Last post
Offline
Last seen: 1 week 21 hours ago
Joined: Apr 19 2022 - 10:36
Posts: 8
Apple II Europlus - issues with video

Hey everyone,

 

I'm quite new to Apple II, have repaired few old pc but never Apple II .

I'm repairing an Apple II Europlus and I have issues with video output..

I have checked the PSU and seems to be ok I got +5 +12 -5,40 -12,75, have removed all IC cleaned with Isopropyl alcool  but still  when switching it on I get the beep and the below image, I have attached some pictures of the MB and the PSU.

P.S.. Monitor is ok, working with my Apple  IIc.

 

Can someone help me with this issue?

 

Thanks Fabrizio

 

Online
Last seen: 1 hour 39 min ago
Joined: Feb 27 2021 - 18:59
Posts: 163
625 line

Can you try the output on a 625-line (15.625 kHz, 50 fps) display? After all, it is a Europlus.

Offline
Last seen: 1 week 21 hours ago
Joined: Apr 19 2022 - 10:36
Posts: 8
Tried with another monitor,

Tried with another monitor, results in the picture.

Both the monitor works with Apple IIc and Apple ///

 

Offline
Last seen: 5 hours 7 sec ago
Joined: Aug 4 2015 - 14:30
Posts: 120
Video Circuit

I would guess that something is wrong with the video circuit.

Maybe one of the components are faulty.

But I'm not an expert in this field.

Offline
Last seen: 3 hours 12 min ago
Joined: Apr 26 2016 - 08:36
Posts: 322
f_fabrizio wrote:Tried with
f_fabrizio wrote:

Tried with another monitor, results in the picture.

Both the monitor works with Apple IIc and Apple ///

 

 

Had a similar problem a while ago.

The issue was with one of the video shift register chips.

 

Off the top of my head I cannot remember which, but it is in the vicinity of C-D 11-13.

 

Does the machine boot and run software?  Can if go into graphics mode whith the picture shifted like that?

If so then my bet is on the video-shft-register issue.

 

Offline
Last seen: 1 week 21 hours ago
Joined: Apr 19 2022 - 10:36
Posts: 8
baldrick wrote: Does the
baldrick wrote:

 

Does the machine boot and run software?  Can if go into graphics mode whith the picture shifted like that?

If so then my bet is on the video-shft-register issue.

 

I do not know I do not have any floppy drive, should get one middle of May

 

 

Offline
Last seen: 1 week 21 hours ago
Joined: Apr 19 2022 - 10:36
Posts: 8
Ciao,made the following tests

Ciao,

made the following tests:

remove all IC and cleaned with Isopropyl alcohol - no changes

tried with another monitor (both monitor working with Apple 2c) - no changes

remove RAM leaving only 16 K - no changes

change the 16K with other RAM ic - nothing changes

remove all ram - got the below screen (I know it does not start without RAm but was just to check) 

Any suggestion?

Thanks Fabrizio

 

 

Offline
Last seen: 3 hours 12 min ago
Joined: Apr 26 2016 - 08:36
Posts: 322
f_fabrizio wrote:baldrick
f_fabrizio wrote:
baldrick wrote:

 

Does the machine boot and run software?  Can if go into graphics mode whith the picture shifted like that?

If so then my bet is on the video-shft-register issue.

 

I do not know I do not have any floppy drive, should get one middle of May

 

 

Type this program and run it (if you can see what you're doing)

It will switch to hi-res-graphics screen and draw screen-wide X.

From that you can see if there are any issues with graphics mode and it will narrow down your troubleshooting.

0 HGR : HOME

10 HCOLOR=5

20 HPLOT 0,0 TO 279,0

30 HPLOT TO 279,159

40 HPLOT TO 0,159

50 HPLOT TO 0,0

60 HCOLOR=2

70 HPLOT 0,0 TO 279,159

80 HCOLOR=1

90 HPLOT 0,159 TO 279,0

100 HOME : HTAB 1 : VTAB 21

120 PRINT "Press any key to continue"

130 GET ANS$

140 HOME : HTAB 1 : VTAB 21

160 PRINT "Thank you for playing"

210 HCOLOR=6

220 HPLOT 0,0 TO 279,0

230 HPLOT TO 279,159

240 HPLOT TO 0,159

250 HPLOT TO 0,0

260 HPLOT 0,0 TO 279,159

270 HPLOT 0,159 TO 279,0

(copied from Devon Hubner)

Offline
Last seen: 1 week 21 hours ago
Joined: Apr 19 2022 - 10:36
Posts: 8
Hi,an update, tested all the

Hi,

an update, tested all the SN74 seies IC on the Mb and found 

C13 - 74LS51N had a broken pin

B1 - 74S175N was faulty

 

changed both with working one but nothing has changed , tested with an 80C card same issue.

 

Any suggestion?

Thanks

Offline
Last seen: 5 hours 7 sec ago
Joined: Aug 4 2015 - 14:30
Posts: 120
What about

the video cable?

Are you using a known good cable?

Offline
Last seen: 1 week 21 hours ago
Joined: Apr 19 2022 - 10:36
Posts: 8
Tried with a couple of cable

Tried with a couple of cable and one is in use with another Apple pc

Log in or register to post comments