Philips VG-8020 broken

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By Telepi

Supporter (4)

Telepi's picture

12-10-2009, 22:11

Hello, I have a VG-8020 broken, I'm repairing it and has wrong system ROM, I have a PROM 27256 for programing and I want to know is whether it serves any MSX ROM image, or must be the concrete model VG-8020 ROM and if so where to get . Thank you very much.

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By Eugeny_Brychkov

Paragon (1232)

Eugeny_Brychkov's picture

12-10-2009, 23:09

Why you decided that ROM is wrong? Where's original chip?

By Telepi

Supporter (4)

Telepi's picture

13-10-2009, 07:03

I have original ROM, I've unsoldered and read with a programmer and there is nothing in it, might have more things wrong, the computer turns on and the screen turns blue, does not work the CAPS.

By Eugeny_Brychkov

Paragon (1232)

Eugeny_Brychkov's picture

13-10-2009, 08:45

Try this one
{moderator edit: sorry, don't link to warez}

If space inside machine permits, use socket for ROM, do not solder chip into the board.

By tfh

Prophet (3305)

tfh's picture

16-10-2009, 22:14

Hmmm, I didn't expect to read this on IRC:

[17:37] <n_n> TFH|Fony did a mod alert yay
[17:38] <n_n> a 3 day old forumpost with link to bios rom
[17:38] <n_n> we're lazy mods =(

I was quite surprised to read this. Of course MIRC doesn't mention "mod alerts" are private, but still. Maybe you should warn people that you might make public who makes mod alerts. It might make people think twice.
Not that I personally really care, but I don't think it's ethical to make this public...

By Sander

Founder (1871)

Sander's picture

17-10-2009, 00:05

hmm, 10 people on IRC, against 30.000 views here? I think it would be more wise to personally address the mod on IRC, than to start a battle about ethics here. I don't think we are ethical at all here ;P

By Eugeny_Brychkov

Paragon (1232)

Eugeny_Brychkov's picture

18-10-2009, 13:20

Arnaud and sander, please explain what's wrong. I read your posts several times and is unable to make any conclusions Smile

Telepi, did you succeeded in programming ROM? Did you solve your problem?

By [D-Tail]

Ascended (8263)

[D-Tail]'s picture

19-10-2009, 12:46

Eugeny: it is not allowed in these forums to link to copyrighted software. Apparently you did just that, for which your post on October 13th has been moderated.

By Telepi

Supporter (4)

Telepi's picture

19-10-2009, 20:16

Yes, I have programmed the ROM (with the link removed, thanks) but the computer still does not start. I remember years ago broke down when I connected to the computer hardware made by me. Then I changed several IC's, 74LS368 (1) 74LS367 (4), CPU Z80, 74LS245, 8255A. Of course I used sockets for each one that I changed. I cut each pin (breaking the IC) and unsolder then 1 by 1 to make sure I did not break the board. I will continue changing IC's, this board has 29 74LSxx, 16 IC's of RAM, etc. I will have to be patient. Any suggestions?. Thanks again.

By RetroTechie

Paragon (1563)

RetroTechie's picture

19-10-2009, 21:36

I remember years ago broke down when I connected to the computer hardware made by me.
Perhaps you (dis)connected hardware while the machine was still on? Similar to people (un)plugging game carts without looking at screen / power LED. Nothing to be ashamed about btw., can happen to the best of us. In that case it's possible a short circuit occurred between supply voltages. Shorting a supply to ground often goes okay, the -12V normally doesn't have enough power to do damage when shorted with another voltage, but in case of +12V -> +5V short (or contact with transistor, IC input etc), many components all over the machine may take a severe hit (or die). A ROM chip that appears 'empty', is nice example of possible results. A mistake in connector pinouts, cartridge plugged in reverse, component placed in wrong orientation, voltage regulator overheating, etc. can all have same result.

I will continue changing IC's, this board has 29 74LSxx, 16 IC's of RAM, etc. I will have to be patient. Any suggestions?
How much time does it cost to swap an IC? How much do you feel that time of yours is worth? And what is the cost of a replacement VG8020?

If this were an expensive machine, okay. But a VG8020 ? Come on, chuck it in a corner (for spare mechanical / power supply parts), grab a cheap replacement, and be done with it. Running Naked in a Field of Flowers

By Eugeny_Brychkov

Paragon (1232)

Eugeny_Brychkov's picture

20-10-2009, 01:32

Telepi, look at my post here http://www.msx.org/forumtopic10326p15.html . Better troubleshoot than replace everything.

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