(Topic ID: 328687)

SOLVED: WPC 089 NVRAM conversion problem

By tripplett

1 year ago


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  • 23 posts
  • 6 Pinsiders participating
  • Latest reply 1 year ago by tripplett
  • Topic is favorited by 2 Pinsiders

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#1 1 year ago

I’ve replaced a Terminator 2’s Mosel 6264 ram with a Ramtron 1608 nvram and it’s not booting. My first nvram and battery removal. Booted and D19 and D21 come on solid and stay on solid. I here a hum from the sound and the display shows nothing. Since led D19 should go out after 1 second I’m wondering if something is up with the blanking signal.

Details:
I cut the 6264 off by snipping each leg off close to the chip then carefully removing each pin one by one. I inspected the board closely for damaged pads and traces and even toned a few pins against the schematic. All were ok. 4DD9337C-73C3-461F-B2C7-D2BAB3C0766F (resized).jpeg4DD9337C-73C3-461F-B2C7-D2BAB3C0766F (resized).jpeg

I then soldered on the socket, again toned many (but not all) of the pins that looked suspect. All were again ok. F1C6B0A1-A77F-441F-8A0D-F93C22F19445 (resized).jpegF1C6B0A1-A77F-441F-8A0D-F93C22F19445 (resized).jpeg

Placed the Ramtronics, reinstalled the board, and no boot. D19 and 20 stay on solid. 63DD67A4-42D3-4BD9-A750-F8802B1E202F (resized).jpeg63DD67A4-42D3-4BD9-A750-F8802B1E202F (resized).jpeg

Verified 4.75v at the nvram so shouldn’t be resetting. Tried one of those no reset boards that pulls 5v from the 12v feed and got 4.88v at the nvram. No change - I didn’t expect one really.

Verified via PinWiki that my jumpers and resistors for the ram and memory are right. W3 out, R93 in. W1 in, W2 out. Somewhere I had seen a boot up sequence but can’t find it right now. I pulled the board and will verify every pin vs schematics but I’m not sure what else to check. Did I get a bad nvram or something? Did I miss a step?

#2 1 year ago
Quoted from tripplett:

I’ve replaced a Terminator 2’s Mosel 6264 ram with a Ramtron 1608 nvram and it’s not booting. My first nvram and battery removal. Booted and D19 and D21 come on solid and stay on solid. I here a hum from the sound and the display shows nothing. Since led D19 should go out after 1 second I’m wondering if something is up with the blanking signal.
Details:
I cut the 6264 off by snipping each leg off close to the chip then carefully removing each pin one by one. I inspected the board closely for damaged pads and traces and even toned a few pins against the schematic. All were ok. [quoted image]
I then soldered on the socket, again toned many (but not all) of the pins that looked suspect. All were again ok. [quoted image]
Placed the Ramtronics, reinstalled the board, and no boot. D19 and 20 stay on solid. [quoted image]
Verified 4.75v at the nvram so shouldn’t be resetting. Tried one of those no reset boards that pulls 5v from the 12v feed and got 4.88v at the nvram. No change - I didn’t expect one really.
Verified via PinWiki that my jumpers and resistors for the ram and memory are right. W3 out, R93 in. W1 in, W2 out. Somewhere I had seen a boot up sequence but can’t find it right now. I pulled the board and will verify every pin vs schematics but I’m not sure what else to check. Did I get a bad nvram or something? Did I miss a step?

Do you have another RAM chip to try? Either a 6264 SRAM or another NVRAM chip? There are fake RAMTRON chips out there. Did you buy it from a reputable source or off ebay? I would try another chip.

Also, the EPROM is uncovered. You should always keep that window covered. Too much exposure to UV will start to erase it. If a bit gets erased or corrupt it won't run. If you have access to an EPROM programmer you could verify the contents are still ok.

#3 1 year ago

Thanks for the reply. I don’t have another ram chip as I chose to cut the pins as close to the chip as possible to save the board. I also don’t have another nvram chip. The Ramtronics NVRAM came from Marco - so I’d hope it was a reputable source.

Yes, I know the eprom is uncovered I have a friend that’s going to flash it with the latest rom as soon as it is out - very soon I think (8.4?). Then I’ll put a label on it. Right now it’s on quite an old version.

#4 1 year ago

https://pinitech.com/blog.php?page=1

Search for "PSA - Not All NVRAM Is The Same Quality"

Marco probably bought a bunch of parts of questionable quality and is selling them. It's a crap shoot. If you purchased it from Marco contact their customer support.

Ramtron hasn't existed for about a decade. They were bought out by Cypress Semiconductor that was recently bought out by Infineon Technologies. Anything with a Ramtron manufacturer is a USED part. For sure.

#5 1 year ago

There’s a trace that runs between pins 8 and 9 that connects to a via under the ram chip that looks slightly suspect.

Everyone is on a good path that the Ramtron could be bad or counterfeit, but you’d need another 6264 or a memory tester to know for sure.

Do you have a logic probe? Could check the address and data lines at the nvram and processor to see if they are moving, to potentially confirm a signal is getting to them… or grab a schematic and buzz out all the traces of the nvram in both directions to make sure no traces are damaged.

#6 1 year ago
Quoted from DumbAss:

Search for "PSA - Not All NVRAM Is The Same Quality"

Marco probably bought a bunch of parts of questionable quality and is selling them. It's a crap shoot. If you purchased it from Marco contact their customer support.

Wow, I had no idea. I'll contact Marco, thanks.

Quoted from johnwartjr:

There’s a trace that runs between pins 8 and 9 that connects to a via under the ram chip that looks slightly suspect.

Everyone is on a good path that the Ramtron could be bad or counterfeit, but you’d need another 6264 or a memory tester to know for sure.

Do you have a logic probe? Could check the address and data lines at the nvram and processor to see if they are moving, to potentially confirm a signal is getting to them… or grab a schematic and buzz out all the traces of the nvram in both directions to make sure no traces are damaged.

I see the one you're talking about. It tests fine between that pad and U6-Pin22. I also checked it between U6 and U9 so all good. Maybe there was some flux on the board when I took the picture.
I will see if anyone local to me has another 6264 or rom tester - or just order a backup 6264 along with another NVRAM. So frustrating - all to remove the batteries on a machine that was working fine. Now I know why I put it off for a few months. I'm checking every pin now against the schematic. Also I do have a logic probe and that is my next step.

Thanks for the advice both of you.

EDIT: I've checked every pin vs the schematic - every one checks fine with a DMM, solder looks good, and there are no shorts between pins.

#7 1 year ago

I'm trying to find someone local in the Raleigh area that has an extra 6264, NVRAM, or ram tester. At this point I'm suspecting a counterfeit chip. Just looking at mine above it looks dull, like it was sanded, compared to the other chips around it. After all that work it is really annoying and disappointing.

#8 1 year ago

The last Ram chip I bought from Marco for a Sorcerer came and it was used and didnt work. I called and sent them some pictures and they sent a new one. Not sure how a used chip got in the bin but they made it right.

#9 1 year ago
Quoted from RGarriott:

Not sure how a used chip got in the bin but they made it right.

Quoted from DumbAss:

Ramtron hasn't existed for about a decade. They were bought out by Cypress Semiconductor that was recently bought out by Infineon Technologies. Anything with a Ramtron manufacturer is a USED part. For sure.

#10 1 year ago

They were the ones that said they weren’t sure how a used chip got in the bin.

#11 1 year ago
Quoted from RGarriott:

They were the ones that said they weren’t sure how a used chip got in the bin.

They are selling through hole DIP-28 (wide) ICs. I don't think I have seen a Cypress Semiconductor branded one of these. Cypress Semiconductor SOIC-28 ICs are common. You should start seeing Infineon Technologies SOIC-28 ICs shortly (if not already). The SOIC-28 requires an adapter to fit a DIP-28 socket.

It's not that they aren't sure how a used IC got in the bin. Anything with a Ramtron branding is a USED part. Marco might have though they bought "new" parts. They are not new parts. They are all used parts.

#12 1 year ago

Very weird. I have read about counterfeit chip’s being sold but didn’t think it would come from marco

#13 1 year ago
Quoted from RGarriott:

I have read about counterfeit chip’s being sold but didn’t think it would come from marco

I think Marco provides a great service to the pinball community. They are great for people who are just getting into restoring and maintaining machines. Their website is great for part numbers and searches / lookups. You will pay a small premium for this convenience but it's a great service.

As with most things in the world (not just pinball), it's always caveat emptor (buyer beware).

If you want a BRAND NEW IC then buy the one from Pinitech. There is another merchant (not barakandl) that is also selling Ramtron ICs at Cypress Semiconductor prices. Those Ramtron ICs from that merchant are also used. The issue with these used modules is that you don't know how much of the rated write cycles have been used prior to the part being pulled and recycled into the pinball ecosystem.

#14 1 year ago

Yea agreed - I though Marco would be a reliable source. But after searching this most of today I agree with @DumbAss. You can’t get a new Ramtron or any 28 pin through hole nvram anywhere that doesn’t look suspicious (ie eBay). You can get a few soic ones and I did see Cypress and Infineon out there. DigiKey wants you to buy 49 at once! Still shopping… I found a good source for through hole to soic boards w/ no pins - but it’s a 15 lot. I might buy 15 if I can get 15 soic nvram somewhere then just sell them here as assembled units - after I confirm they all work of course. Seems this is a common problem.

I also found the Pinitech source and will go that route if I just want one.
It looks like FM16W08 is the replacement for FM1608.

#15 1 year ago
Quoted from tripplett:

DigiKey wants you to buy 49 at once!

Those are being sold by Rochester Electronics. They have a lot of NOS. If you buy from them, they are likely new. Rochester Electronics often have large minimum purchase quantities which is definitely prohibitive for the average buyer.

Quoted from tripplett:

It looks like FM16W08 is the replacement for FM1608.

Glad you found this. You can buy either the tube or tape/reel packaging. It's the same core IC. These are SOIC-28 only. This IC is just not being made as DIP-28.

https://www.digikey.com/en/products/detail/infineon-technologies/FM16W08-SGTR/4090349

You also nailed the other side of the issue. You need the adapter boards and pins. That costs $. Then there's the labor of assembling the SOIC-28 adapter and male pins. For all the effort required, the $25 that Pinitech is asking is quite reasonable. NVRAMs used to be $15 or $20 a few years ago (before the onset of the pandemic and supply chain / manufacturing issues).

#16 1 year ago
Quoted from DumbAss:

For all the effort required, the $25 that Pinitech is asking is quite reasonable. NVRAMs used to be $15 or $20 a few years ago (before the onset of the pandemic and supply chain / manufacturing issues).

It is a good deal. But I like to tinker, 3D print, solder, make things, and make things work. I’ve even etched a few custom boards for RC hobbies. I want to help this problem. It looks like I can get enough supplies to build 15 NVRAM for lower than Pinitech’s price . I don’t want to compete - just build 3 for me and then sell the rest either as a kit or assembled for like $20 shipped.

#17 1 year ago

I have got several from weebly when he had them in stock, the last few have been from pinball electronics.

#18 1 year ago

The sleeve of 1608's I bought in 2006 is looking sweet now

Especially after I found them after forgetting I had them. Just used one on my AFM after the lovely duracell batteries I had installed about 6 mo ago leaked.

#19 1 year ago

So I received a new NVRAM module from PinballLife today and swapped it in. It still doing the same thing so perhaps that NVRAM from Marco is good after all.

The blanking line is being held high so it won't boot and D19 and D21 stay lit. I'm going to retrace everything yet again. i'm not sure what else to try at this point. I mean everything looks great. I do have an option to borrow a good working CP board but I'm going to go out on a limb here and say that one will probably work fine. I'm also going to get the EPROM tested. With no cover on it originally and me working under a bright work light to solder it's possible that now has issues.

https://www.pinballlife.com/anypin-dmd-nvram-battery-eliminator.html

#20 1 year ago
Quoted from tripplett:

So I received a new NVRAM module from PinballLife today and swapped it in. It still doing the same thing so perhaps that NVRAM from Marco is good after all.

Strictly, this is NOT proof that the FM1608 is good. This only adds to the data point that there is likely something wrong on the board. If it was working before you touched the board and now it is not working then it is likely your changes are the cause. What would prove the FM1608 is good is putting in a known good board and seeing the board POST.

Quoted from tripplett:

The blanking line is being held high so it won't boot and D19 and D21 stay lit. I'm going to retrace everything yet again.

Yes. Recheck ALL connections from U8. There are four potential branches from each of the 28 pins.

  1. Component side "up".
  2. Component side "down".
  3. Solder side "up".
  4. Solder side "down".

Not all branches are used.

A successful CPU board POST requires these ICs to be working:

  • U4=Processor (68B09E).
  • U6=EPROM (27C040 or equivalent).
  • U8=SRAM (6264 or equivalent).
  • U9=ASIC.
Quoted from tripplett:

I mean everything looks great.

<facetious>Your eyes don't have electron vision. Use something that gives you electron vision (DMM).</facetious>

Quoted from tripplett:

I'm also going to get the EPROM tested. With no cover on it originally and me working under a bright work light to solder it's possible that now has issues.

Odds of this happening are LOW. Not zero but low. Focus on the changes (work) that you did to the board. A common cause of issues that I have to repair is problematic board work done by someone immediately working on a board prior to asking me to look at it. This is not a personal attack. It's just a fact stating a common presentation cause.

You can also install a known good EPROM from another board. Connect ONLY the power (J210) and NOTHING ELSE.

This image might help as a guide but it's not definitive. It was made with the TwoBits board as the template, not an OEM board.

u8.jpgu8.jpg

#21 1 year ago

Excellent reply DA - no personal attack taken and I appreciate the help. The removal was good and looks clean. I feel confident with solder work but something could have easily happened. I cut all the pins off, flipped the board over, clipped a small pair of hemostats to each pin one by one, and unsoldered them letting gravity let them fall out. No bruit force was applied.

I’m going to borrow a known working cpu board to verify the two nvram chips. Those images will also definitely help, thanks. I did end to end testing but I didn’t do any testing for traces as they passed between the other pads. Most tests were with only J210 connected. Logic probe tests also seem to show correct output but I only checked at the chip, not downstream. I’m going to do that next. I did check the top of U8 socket to as far downstream as I could on the schematic but may have missed something. I’ll work on checking all 4 branches this way. By the way tonight the eprom was checked and was fine/verified too so you’re right - it isn’t the eprom.

Thanks for the advice, I’ll let you know when I find the culprit.

#22 1 year ago

I have several meanwell 12v DC power supplies from another hobby. I also have several 5v power supplies along with 5v buck converters. I had planned on repinning J210 so I have a few plugs and 100 pins. Anyone ever set up a bench test power supply for this kind of thing? It would make testing with the logic probe much easier.

I'm going to take a guess here looking at these schematics that only 5v is needed to test the board and that 12v just passes through the board for the switches via U16-20. Testing the logic only needs the 5v connection.

Edit: Well I should have just searched…
https://pinside.com/pinball/forum/topic/dc-benchtop-power-supply#post-4528152

#23 1 year ago

Found the problem. U8 NVRAM D2 (pin13) to U9 ASIC D2 (pin 31) had no connection. U8 was pulsing but U9 was not. Didn't tone either.

Investigated and discovered the trace was damaged where a thin horseshoe trace comes off the pin's pad to a through hole pad just off the chip. I've circled the area in yellow and marked the break in red. The through hole continues on the top of the board to pin 31 at the ASIC, marked with a red arrow. Damage must have occurred after my post solder tests but before putting the board back in the machine. That or it was just barely connected at first.

I connected a small 1/2" piece of 30 awg Kynar between the chip pad and the through hole pad and the board booted right up. It also booted with both the Ramtron and the PinballLife NVRAMs on the bench. Going to put them in the machine and test both to be sure.
EDIT: both nvrams were fine.

I learned a lot through this. Working on these 30 year old fragile areas of the board are not for the faint of heart. I'd do it again. And I learned a lot about each chip's datasheet and how the reset and halt circuits work in the process. I also made a bench power supply that helped with the testing immensely.
Thanks for all the help.

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