RISC 2500 blues

Carl Bicknell · Post by **Carl Bicknell** » Wed Feb 25, 2015 5:48 pm

The good news: I won a RISC 2500 on ebay last month! I played a dozen games against it and it was lots of fun!!

The bad news: Now it is dead. When I try to power up I get random lights round the outside of the board and then nothing. Sometimes just nothing.

Can anyone help? I don't think it's the seller's fault.

I *may* have plugged in the wrong power supply but I don't think I pressed the ON button and the other power supply wasn't in the mains, so that shouldn't be the cause. I can't understand why it has just died.

Can anyone help? I'm prepared to spend money to get it working again...

spacious_mind · Post by **spacious_mind** » Wed Feb 25, 2015 5:58 pm

Carl Bicknell wrote:The good news: I won a RISC 2500 on ebay last month! I played a dozen games against it and it was lots of fun!!

The bad news: Now it is dead. When I try to power up I get random lights round the outside of the board and then nothing. Sometimes just nothing.

Can anyone help? I don't think it's the seller's fault.

I *may* have plugged in the wrong power supply but I don't think I pressed the ON button and the other power supply wasn't in the mains, so that shouldn't be the cause. I can't understand why it has just died.

Can anyone help? I'm prepared to spend money to get it working again...

Hi Carl,

Try to open it and very carefully remove the game ROM (without bending the pins) and then just as carefully put the game ROM back in. I have had successes with a couple of computers by doing just that and they worked again, it is like they just reset themselves.

Failing that, you will need a repair man.

Regards

Carl Bicknell · Post by **Carl Bicknell** » Wed Feb 25, 2015 6:11 pm

spacious_mind wrote:
Carl Bicknell wrote:The good news: I won a RISC 2500 on ebay last month! I played a dozen games against it and it was lots of fun!!

The bad news: Now it is dead. When I try to power up I get random lights round the outside of the board and then nothing. Sometimes just nothing.

Can anyone help? I don't think it's the seller's fault.

I *may* have plugged in the wrong power supply but I don't think I pressed the ON button and the other power supply wasn't in the mains, so that shouldn't be the cause. I can't understand why it has just died.

Can anyone help? I'm prepared to spend money to get it working again...
Hi Carl,

Try to open it and very carefully remove the game ROM (without bending the pins) and then just as carefully put the game ROM back in. I have had successes with a couple of computers by doing just that and they worked again, it is like they just reset themselves.

Failing that, you will need a repair man.

Regards

Thanks for your suggestion. There's so little room around the ROM I can't get even a small electrical screwdriver in, let alone my fingers.

Looks like I need a Saitek repair man from the 90's....

Carl Bicknell · Post by **Carl Bicknell** » Wed Feb 25, 2015 6:58 pm

I finally got the ROM off and back on. Yikes that was scary.

However, no change.

Does anyone know a Saitek man...?

kgvetter · Post by **kgvetter** » Wed Feb 25, 2015 8:25 pm

Hello,

I am familiar with the problem, fact is that the GAL-chips, this is two chips in the machine containing the General Address Logic tend to give up and lose their content. I can give you the address of the only repair-person (in Germany) which has conquered the problem by cracking the copyprotection of these chips and consequently has been able to copy the contents to new chips. It has worked for me and he has reanimated at least 6 Risc 2500s I know of.

Greetings, Gerhard

Carl Bicknell · Post by **Carl Bicknell** » Wed Feb 25, 2015 8:29 pm

kgvetter wrote:Hello,

I am familiar with the problem, fact is that the GAL-chips, this is two chips in the machine containing the General Address Logic tend to give up and lose their content. I can give you the address of the only repair-person (in Germany) which has conquered the problem by cracking the copyprotection of these chips and consequently has been able to copy the contents to new chips. It has worked for me and he has reanimated at least 6 Risc 2500s I know of.

Greetings, Gerhard

That would be extremely helpful, thankyou. I have a feeling this is going to cost more than the machine is worth, but I want to see it through. Could you PM me?

Thanks.

IvenGO · Post by **IvenGO** » Thu Feb 26, 2015 4:57 am

First, try ACL-procedure; if not help - after shutting power off start it by pressing BACK + ON buttons (hold them for few seconds), if not again - replace RAM-chips by new...

Larry · Post by **Larry** » Thu Feb 26, 2015 11:56 am

You might also try powering up by simply pressing and releasing the ON
button. Then clear the RAM via the options menu, ie, go to
Menu -> Special -> Clear RAM.
However it does seem we are flogging a dead horse. The German guy
that can copy GAL chips is the way to a good permanent result. I think I've
got another piece of bad news. Most risc2500's have their GAL chips
soldered into place, unlike the eprom you pulled out and replaced which
was a push fit. The bad GALs will have to be de soldered and replaced by chip
holders. The replacement GAL's push easily into the chip holders. You
may be lucky and have a risc from late in the production run, which will
have push fit GALs. From what I'm gathering, the soldering job is best done
by an experienced person.

Whatever you do, don't get disheartened and sell the risc for peanuts.
You will get it going sooner or later and it will have its value back
as a working unit.
L

Carl Bicknell · Post by **Carl Bicknell** » Thu Feb 26, 2015 1:52 pm

People here are extremely helpful, and it's much appreciated.

I tried all the suggestions and still...nothing. There is a repairman I've found locally who said he'll look at it, but he didn't sound confident.

I'm still hunting! Love the optimism though Larry!

paco5560 · Post by **paco5560** » Fri Mar 13, 2015 2:51 pm

I can help.
I have one down because GALS and power supply, there are 2 transistors that blows out they are $0.50 each I can replace them, just let me take a look on your machine, you only pay for handling, I am in Indianapolis In.
Contact me (paco5560) we can make it work. I am 35 year electronic technologist, an chess lover, I repair my own machines, and try to have the machines up and running.
Best regards.
Francisco Hernandez

Carl Bicknell · Post by **Carl Bicknell** » Tue Mar 17, 2015 12:43 pm

paco5560 wrote:I can help.
I have one down because GALS and power supply, there are 2 transistors that blows out they are $0.50 each I can replace them, just let me take a look on your machine, you only pay for handling, I am in Indianapolis In.
Contact me (paco5560) we can make it work. I am 35 year electronic technologist, an chess lover, I repair my own machines, and try to have the machines up and running.
Best regards.
Francisco Hernandez

Hi,

thanks for the offer - PM sent

paco5560 · Post by **paco5560** » Tue Mar 17, 2015 1:04 pm

Carl Bicknell wrote:
paco5560 wrote:I can help.
I have one down because GALS and power supply, there are 2 transistors that blows out they are $0.50 each I can replace them, just let me take a look on your machine, you only pay for handling, I am in Indianapolis In.
Contact me (paco5560) we can make it work. I am 35 year electronic technologist, an chess lover, I repair my own machines, and try to have the machines up and running.
Best regards.
Francisco Hernandez
Hi,

thanks for the offer - PM sent

maybe some time we can try skype, that way you come to my repair place, I know the feeling, and I am with you, just trying you to see, who I am.
I can show you some of my chess computers, I am finishing a Novag Citrine, you know in this one all the sides come apart, I sand them and apply an epoxy paint, is still drying, when finished, I will send you some pictures.
In the same forum I read about you, I contact Arno, the guy that has the GAL'S for mine in Germany, I am waiting on him in how to pay for them, I hope as soon as I have mine working, send you pictures too.
Well my offer is still there, take your time.
Thanks keep in touch.
Francisco Hernandez

Carl Bicknell · Post by **Carl Bicknell** » Tue Mar 17, 2015 3:06 pm

I'm confused.
I thought it was just a couple of blown transistors. If you're also buying Gals from Germany then it can't be that simple...

paco5560 · Post by **paco5560** » Tue Mar 17, 2015 5:03 pm

Carl Bicknell wrote:I'm confused.
I thought it was just a couple of blown transistors. If you're also buying Gals from Germany then it can't be that simple...

In that many experience years I am buying it just in case, and cost of a
RISC 2500 worth it, I am doing this, beacouse in my univerzal readers, one gal is not reporting reading data of any kind, among other tests, of input-output for this devises (GALS), one is bad.
This gals are reading protected devices, I work a lot on this making develops, I have no output of any kind in one of them, I can not reverse engineering, with no good ones is totally impossible. I know what I am talking about.
For marketing purposes all people asume electronics devices are expencive, gals are $2.50 each what makes them expensive is the time in writing all boolean equations needed. Well I do not want go far technical.
All the technical support is my part to help.
If it is more complicated than expeced on your machine, I let you know, but this depends on some tests needed to find out the problem.
I can tell for the test on mine, main EPROM, with the program that makes this machine so powerfull, is in good shape and power supply transistors went bad ( they are "open" if found "sort circuited" more or all devices in the main board could went bad ). Hope I am not adding more questions to you.
Thanks for your patience.
Francisco H.

HIARCS Chess Forums

RISC 2500 blues

RISC 2500 blues

Re: RISC 2500 blues

Re: RISC 2500 blues

I can help to repair your RISC 2500

Re: I can help to repair your RISC 2500

Re: I can help to repair your RISC 2500

please don't be