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Posted By

Joe
on 2012-02-21
02:59:09
 HELP

I recently bought a commodore plus/4 hooked it up turned it on and it won't work
The power LED turns on however there is no audio or video I have it connected to my Television using the RF out on the computer the cord is fine, fuse is good, no burnt or exploded capacitors and no shorts. My television desplays random patterns ow wight noise in one patrern i can kind of make out what looks like blocks. any one know how to or where to fix this? I tryed reseating the IC's and it did nothing

Posted By

Luca
on 2012-02-21
03:16:10
 Re: HELP

This thread is just few rows below.
Even in your case, it would look like a bad TED IC :/ Follow the other thread's links and good luck for a succesful fixing.

Posted By

crock
on 2012-02-21
07:25:37
 Re: HELP

You didn't state where you are. Are you sure that the +4 is the same standard as your local TV standard? If the power is good, you would normally expect to be able to tune your TV into a black screen. If the answer to the first question is yes, and the second no, I would next try the PSU. Do you have a multimeter to test the +5V ?

Rob

Posted By

Joe
on 2012-02-21
12:10:41
 Re: HELP

Yes, I do have a multimeter where would I check for voltage? And I believe my television is NTSC

Posted By

crock
on 2012-02-21
13:26:52
 Re: HELP

+5V is available on many places on the board but the safest place to get it on pin 2 of the user port, where the yellow arrow points on the picture here:

http://inchocks.co.uk/commodore/Plus4Board.jpg

Second, check the number on the chip pointed to by the red arrow on your board. If it's an NTSC machine, this should say 318005-04 or 318005-05 (or maybe -03, but rarely.)

If this chip is 318004-0x (where x is 1 -> 5), then you have a PAL machine.

Rob

Posted By

Joe
on 2012-02-22
01:49:35
 Re: HELP

The machine is NTSC and I am getting the 5v from pin 2

Posted By

MMS
on 2012-02-22
10:51:52
 Re: HELP

You may check the standard CVBS video output, connecting to TV Yellow/White/Red AV In port.This signal do not "suffer" several transcoding by the modulatiorn, and in fact it is sharper than RF too.
You may need a Video 8-pol Din connector (DIN45326 or DIN41524, tha later is perfect, the more typical first need a hack: uou should cut out pins 7 and 8, but they are not used at all)
Pin 4 is Composit video
Pin 3 is Audio out
and you may work out an Svideo connection too, but it was told to be worse than CVBS, (so forget it, more wire for worse picture quality...)

In case you were able to connect audio out at least to an amplifier, you may try a SOUND command too. At least you will now, if the CPU works, if sound comes out.

Sorry, Hungarian, but you may find the pin layout here:
http://www.machines.hu/cgi-bin/machines/new/cikk.cgi?cikk=329&oldal=1&pda=&noimg=

PS: I have 2 similar machines... But I do not hurt them, give to someone who may use them as IC source.

Posted By

MMS
on 2012-02-22
10:53:02
 Re: HELP

Sorry for the lot of typo errors, but little tired after that loong day.



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