Can this board be revived. Merlin II R3 processor 1

[Bichela]

I got my old Merlin II processor with R3 laying around that went kaput. Red light stays on and never turns off. That is why we upgraded to the Merlin Legend/Magix CKE5 Processor.

I removed the rechargeable battery and it still won't boot. Replaced several capacitors and again nothing.

I believe a sudden power cycle caused the board to go offline.

I am fairly technical and willing to take the spare time to get it working. With no backup battery on the board you would think it would have cleared the static ram by now to allow it to start from scratch.

What is the next step to restoring this vintage piece of history?

 

[Dexman]

Short of trying to locate another processor online, I wouldn't put too much effort into trying to resurrect the existing one.

I "FEATURE 00"

http://dexman.webs.com/

 

[Bichela]

Since it is a hobbyist system... I am willing to do so. If at least to learn WHY it isn't working.

 

[merlinman]

Another LEGEND PROCESSOR is CHEAP on EBAY. I'd go there. You can look at my website too.....

http://merlinmanswebpage.yolasite.com

 

[exsmogger]

I'd guess one or more of the main chips are blown. As others have suggested, don't waste too much time on this.

Brian Cox
Georgia Telephone

http://Georgia-Telephone.com

http://www.linkedin.com/in/briancox1952

 

[merlinman]

The thing about The MERLIN II is there's no SPM programming, no good way to back it up and the batteries do go bad, and then all the memory is gone.

I ALWAYS replace them with at least a LEGEND R7.0.

That gives all the things you could ever want in a system using ATL Sets. + you can add voicemail.

http://merlinmanswebpage.yolasite.com

 

[Bichela]

The irony is the processor has a Admin port however. At least mine does. it also has that VME bus connector where the PCMCIA card slot would be. Clearly, the designers were planning on a windows/dos SPM for this model. Even my manuals mention that there was a SPM for this.

I wonder if the oscillator/clock went bad. I don't have a logic probe or another backplane/power supply to test this. I do know there is a diagnostic module that can plug into that VME bus type connector. I have seen it on eBay.

The biggest headache is all the chips are soldered in. There is no sockets. so doing a chip swap becomes very difficult.

 

[merlinman]

On a similar note, One day we (Avaya Tier 3) got a call on a MERLIN II that had a module in it with only 1 PORT. I forget what the tech called the service it had going into it, but we were able to get him to send us the card so we could figure it out. To our surprise, it was a T1 Module. That wasn't even offered on the MERLIN II. More research found that this one was a ONE TIME DEAL, and the support for it previously was done by Bell Labs. They had never even bothered to mention this Monster to us. As I recall, it didn't have a "STANDARD" T1 Module number.

So, there are some "ghosts" of weird things out there some where. Like the 412 ETR Module in my basement. (That does work, BTW)

http://merlinmanswebpage.yolasite.com

 

[pccsipoffice]

I wont tell you not to waist your time on it. But I would find one somewhere that
works so you can at least do some kind of voltage comparison or resistance comparison.
Even the folks that were trained to work on these component level often had specialized
equipment to speed up the testing and repair of these things.
good luck.

 

[Bichela]

I did a tech video on this, I disassembled the board and show its guts on YouTube. It appears either the RESET line of the 68000 processor is staying active low. The clock is not starting. Here is the link, warning. gets a bit long though as it get to non board issues in the end.

No matter, here is the video link.

https://youtu.be/HcFMm1Tj1Zg

 

[Bichela]

I wonder if the clock oscillator has failed. there are two of them near the MC68000PB chip. Does anyone have a schematic for this board? Would make tracing the problem a bit easier.

Also there is a Merlin 2 diagnostic module on Ebay. would this help to determine if the clock has gone bad. or perhaps the static ram modules.

 

[merlinman]

I was a TIER-3 Tech Support Engineer, and I worked DIRECTLY with BELL LABS on a lot of things for this product. I have never seen, nor have I ever heard anyone discuss a Schematic for these processors.

You could reverse Engineer to a degree (Connections to and from IC's) but I doubt you'll ever see a schematic.

I must say, you have much more time on your hands than I do, and I've been retired for over 15 Years.

http://merlinmanswebpage.yolasite.com

 

[Bichela]

I take that as a compliment if course, as Louis Rossmann would say, when you got paying customers, unless they want to pay more than what the board is worth, you swap it out. But, if you want to use it as a learning expirence. You can play with it as you have time.